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DisplayPort to Save the Day?
During an impromptu meeting with AMD this week, the company's Corporate Vice President for Visual Computing, Raja Koduri, presented me with an interesting demonstration of a technology that allowed the refresh rate of a display on a Toshiba notebook to perfectly match with the render rate of the game demo being shown. The result was an image that was smooth and with no tearing effects. If that sounds familiar, it should. NVIDIA's G-Sync was announced in November of last year and does just that for desktop systems and PC gamers.
Since that November unveiling, I knew that AMD would need to respond in some way. The company had basically been silent since learning of NVIDIA's release but that changed for me today and the information discussed is quite extraordinary. AMD is jokingly calling the technology demonstration "FreeSync".
Variable refresh rates as discussed by NVIDIA.
During the demonstration AMD's Koduri had two identical systems side by side based on a Kabini APU . Both were running a basic graphics demo of a rotating windmill. One was a standard software configuration while the other model had a modified driver that communicated with the panel to enable variable refresh rates. As you likely know from our various discussions about variable refresh rates an G-Sync technology from NVIDIA, this setup results in a much better gaming experience as it produces smoother animation on the screen without the horizontal tearing associated with v-sync disabled.
Obviously AMD wasn't using the same controller module that NVIDIA is using on its current G-Sync displays, several of which were announced this week at CES. Instead, the internal connection on the Toshiba notebook was the key factor: Embedded Display Port (eDP) apparently has a feature to support variable refresh rates on LCD panels. This feature was included for power savings on mobile and integrated devices as refreshing the screen without new content can be a waste of valuable battery resources. But, for performance and gaming considerations, this feature can be used to initiate a variable refresh rate meant to smooth out game play, as AMD's Koduri said.
Introduction and Unboxing
We've been covering NVIDIA's new G-Sync tech for quite some time now, and displays so equipped are finally shipping. With all of the excitement going on, I became increasingly interested in the technology, especially since I'm one of those guys who is extremely sensitive to input lag and the inevitable image tearing that results from vsync-off gaming. Increased discussion on our weekly podcast, coupled with the inherent difficulty of demonstrating the effects without seeing G-Sync in action in-person, led me to pick up my own ASUS VG248QE panel for the purpose of this evaluation and review. We've generated plenty of other content revolving around the G-Sync tech itself, so lets get straight into what we're after today - evaluating the out of box installation process of the G-Sync installation kit.
All items are well packed and protected.
Included are installation instructions, a hard plastic spudger for opening the panel, a couple of stickers, and all necessary hardware bits to make the conversion.
Sapphire Triple Fan Hawaii
It was mid-December when the very first custom cooled AMD Radeon R9 290X card hit our offices in the form of the ASUS R9 290X DirectCU II. It was cooler, quieter, and faster than the reference model; this is a combination that is hard to pass up (if you could buy it yet). More and more of these custom models, both in the R9 290 and R9 290X flavor, are filtering their way into PC Perspective. Next on the chopping block is the Sapphire Tri-X model of the R9 290X.
Sapphire's triple fan cooler already made quite an impression on me when we tested a version of it on the R9 280X retail round up from October. It kept the GPU cool but it was also the loudest of the retail cards tested at the time. For the R9 290X model, Sapphire has made some tweaks to the fan speeds and the design of the cooler which makes it a better overall solution as you will soon see.
The key tenets for any AMD R9 290/290X custom cooled card is to beat AMD's reference cooler in performance, noise, and variable clock rates. Does Sapphire meet these goals?
The Sapphire R9 290X Tri-X 4GB
While the ASUS DirectCU II card was taller and more menacing than the reference design, the Sapphire Tri-X cooler is longer and appears to be more sleek than the competition thus far. The bright yellow and black color scheme is both attractive and unique though it does lack the LED light that the 280X showcased.
Sapphire has overclocked this model slightly, to 1040 MHz on the GPU clock, which puts it in good company.
|AMD Radeon R9 290X||ASUS R9 290X DirectCU II||Sapphire R9 290X Tri-X|
|Rated Clock||1000 MHz||1050 MHz||1040 MHz|
|Memory Clock||5000 MHz||5400 MHz||5200 MHz|
|TDP||~300 watts||~300 watts||~300 watts|
|Peak Compute||5.6 TFLOPS||5.6+ TFLOPS||5.6T TFLOPS|
There are three fans on the Tri-X design, as the name would imply, but each are the same size unlike the smaller central fan design of the R9 280X.
The First Custom R9 290X
It has been a crazy launch for the AMD Radeon R9 series of graphics cards. When we first reviewed both the R9 290X and the R9 290, we came away very impressed with the GPU and the performance it provided. Our reviews of both products resulted in awards of the Gold class. The 290X was a new class of single GPU performance while the R9 290 nearly matched performance at a crazy $399 price tag.
But there were issues. Big, glaring issues. Clock speeds had a huge amount of variance depending on the game and we saw a GPU that was rated as "up to 1000 MHz" running at 899 MHz in Skyrim and 821 MHz in Bioshock Infinite. Those are not insignificant deltas in clock rate that nearly perfectly match deltas in performance. These speeds also changed based on the "hot" or "cold" status of the graphics card - had it warmed up and been active for 10 minutes prior to testing? If so, the performance was measurably lower than with a "cold" GPU that was just started.
That issue was not necessarily a deal killer; rather, it just made us rethink how we test GPUs. The fact that many people were seeing lower performance on retail purchased cards than with the reference cards sent to press for reviews was a much bigger deal. In our testing in November the retail card we purchased, that was using the exact same cooler as the reference model, was running 6.5% slower than we expected.
The obvious hope was the retail cards with custom PCBs and coolers would be released from AMD partners and somehow fix this whole dilemma. Today we see if that was correct.
A slightly smaller MARS
The NVIDIA GeForce GTX 760 was released in June of 2013. Based on the same GK104 GPU as the GTX 680, GTX 670 and GTX 770, the GTX 760 disabled a couple more of the clusters of processor cores to offer up impressive performance levels for a lower cost than we had seen previously. My review of the GTX 760 was very positive as NVIDIA had priced it aggressively against the competing products from AMD.
As for ASUS, they have a storied history with the MARS brand. Typically an over-built custom PCB with two of the highest end NVIDIA GPUs stapled together, the ASUS MARS cards have been limited edition products with a lot of cache around them. The first MARS card was a dual GTX 285 product that was the first card to offer 4GB of memory (though 2GB per GPU of course). The MARS II took a pair of GTX 580 GPUs and pasted them on a HUGE card and sold just 1000 of them worldwide. It was heavy, expensive and fast; blazing fast. But at a price of $1200+ it wasn't on the radar of most PC gamers.
Interestingly, the MARS iteration for the GTX 680 never occurred and why that is the case is still a matter of debate. Some point the finger at poor sales and ASUS while others think that NVIDIA restricted ASUS' engineers from being as creative as they needed to be.
Today's release of the ASUS ROG MARS 760 is a bit different - this is still a high end graphics card but it doesn't utilize the fastest single-GPU option on the market. Instead ASUS has gone with a more reasonable design that combines a pair of GTX 760 GK104 GPUs on a single PCB with a PCI Express bridge chip between them. The MARS 760 is significantly smaller and less power hungry than previous MARS cards but it is still able to pack a punch in the performance department as you'll soon see.
Quality time with G-Sync
Readers of PC Perspective will already know quite alot about NVIDIA's G-Sync technology. When it was first unveiled in October we were at the event and were able to listen to NVIDIA executives, product designers and engineers discuss and elaborate on what it is, how it works and why it benefits gamers. This revolutionary new take on how displays and graphics cards talk to each other enables a new class of variable refresh rate monitors that will offer up the smoothness advantages of having V-Sync off, while offering the tear-free images normally reserved for gamers enabling V-Sync.
NVIDIA's Prototype G-Sync Monitor
We were lucky enough to be at NVIDIA's Montreal tech day while John Carmack, Tim Sweeney and Johan Andersson were on stage discussing NVIDIA G-Sync among other topics. All three developers were incredibly excited about G-Sync and what it meant for gaming going forward.
Also on that day, I published a somewhat detailed editorial that dug into the background of V-sync technology, why the 60 Hz refresh rate existed and why the system in place today is flawed. This basically led up to an explanation of how G-Sync works, including integration via extending Vblank signals and detailed how NVIDIA was enabling the graphics card to retake control over the entire display pipeline.
In reality, if you want the best explanation of G-Sync, how it works and why it is a stand-out technology for PC gaming, you should take the time to watch and listen to our interview with NVIDIA's Tom Petersen, one of the primary inventors of G-Sync. In this video we go through quite a bit of technical explanation of how displays work today, and how the G-Sync technology changes gaming for the better. It is a 1+ hour long video, but I selfishly believe that it is the most concise and well put together collection of information about G-Sync for our readers.
The story today is more about extensive hands-on testing with the G-Sync prototype monitors. The displays that we received this week were modified versions of the 144Hz ASUS VG248QE gaming panels, the same ones that will in theory be upgradeable by end users as well sometime in the future. These monitors are TN panels, 1920x1080 and though they have incredibly high refresh rates, aren't usually regarded as the highest image quality displays on the market. However, the story about what you get with G-Sync is really more about stutter (or lack thereof), tearing (or lack thereof), and a better overall gaming experience for the user.
Another retail card reveals the results
Since the release of the new AMD Radeon R9 290X and R9 290 graphics cards, we have been very curious about the latest implementation of AMD's PowerTune technology and its scaling of clock frequency as a result of the thermal levels of each graphics card. In the first article covering this topic, I addressed the questions from AMD's point of view - is this really a "configurable" GPU as AMD claims or are there issues that need to be addressed by the company?
The biggest problems I found were in the highly variable clock speeds from game to game and from a "cold" GPU to a "hot" GPU. This affects the way many people in the industry test and benchmark graphics cards as running a game for just a couple of minutes could result in average and reported frame rates that are much higher than what you see 10-20 minutes into gameplay. This was rarely something that had to be dealt with before (especially on AMD graphics cards) so to many it caught them off-guard.
Because of the new PowerTune technology, as I have discussed several times before, clock speeds are starting off quite high on the R9 290X (at or near the 1000 MHz quoted speed) and then slowly drifting down over time.
Another wrinkle occurred when Tom's Hardware reported that retail graphics cards they had seen were showing markedly lower performance than the reference samples sent to reviewers. As a result, AMD quickly released a new driver that attempted to address the problem by normalizing to fan speeds (RPM) rather than fan voltage (percentage). The result was consistent fan speeds on different cards and thus much closer performance.
However, with all that being said, I was still testing retail AMD Radeon R9 290X and R9 290 cards that were PURCHASED rather than sampled, to keep tabs on the situation.
EVGA Brings Custom GTX 780 Ti Early
Reference cards for new graphics card releases are very important for a number of reasons. Most importantly, these are the cards presented to the media and reviewers that judge the value and performance of these cards out of the gate. These various articles are generally used by readers and enthusiasts to make purchasing decisions, and if first impressions are not good, it can spell trouble. Also, reference cards tend to be the first cards sold in the market (see the recent Radeon R9 290/290X launch) and early adopters get the same technology in their hands; again the impressions reference cards leave will live in forums for eternity.
All that being said, retail cards are where partners can differentiate and keep the various GPUs relevant for some time to come. EVGA is probably the most well known NVIDIA partner and is clearly their biggest outlet for sales. The ACX cooler is one we saw popularized with the first GTX 700-series cards and the company has quickly adopted it to the GTX 780 Ti, released by NVIDIA just last week.
I would normally have a full review for you as soon as we could but thanks to a couple of upcoming trips that will keep me away from the GPU test bed, that will take a little while longer. However, I thought a quick preview was in order to show off the specifications and performance of the EVGA GTX 780 Ti ACX.
As expected, the EVGA ACX design of the GTX 780 Ti is overclocked. While the reference card runs at a base clock of 875 MHz and a typical boost clock of 928 MHz, this retail model has a base clock of 1006 MHz and a boost clock of 1072 MHz. This means that all 2,880 CUDA cores are going to run somewhere around 15% faster on the EVGA ACX model than the reference GTX 780 Ti SKUs.
We should note that though the cooler is custom built by EVGA, the PCB design of this GTX 780 Ti card remains the same as the reference models.
An issue of variance
AMD just sent along an email to the press with a new driver to use for Radeon R9 290X and Radeon R9 290 testing going forward. Here is the note:
We’ve identified that there’s variability in fan speeds across AMD R9 290 series boards. This variability in fan speed translates into variability of the cooling capacity of the fan-sink.
The flexibility of AMD PowerTune technology enables us to correct this variability in a driver update. This update will normalize the fan RPMs to the correct values.
The correct target RPM values are 2200RPM for the AMD Radeon R9 290X ‘Quiet mode’, and 2650RPM for the R9 290. You can verify these in GPU-Z.
If you’re working on stories relating to R9 290 series products, please use this driver as it will reduce any variability in fan speeds. This driver will be posted publicly tonight.
Great! This is good news! Except it also creates some questions.
When we first tested the R9 290X and the R9 290, we discussed the latest iteration of AMD's PowerTune technology. That feature attempts to keep clocks as high as possible under the constraints of temperature and power. I took issue with the high variability of clock speeds on our R9 290X sample, citing this graph:
I then did some digging into the variance and the claims that AMD was building a "configurable" GPU. In that article we found that there were significant performance deltas between "hot" and "cold" GPUs; we noticed that doing simple, quick benchmarks would produce certain results that were definitely not real-world in nature. At the default 40% fan speed, Crysis 3 showed 10% variance with the 290X at 2560x1440:
GK110 in all its glory
I bet you didn't realize that October and November were going to become the onslaught of graphics cards it has been. I know I did not and I tend to have a better background on these things than most of our readers. Starting with the release of the AMD Radeon R9 280X, 270X and R7 260X in the first week of October, it has pretty much been a non-stop battle between NVIDIA and AMD for the hearts, minds, and wallets of PC gamers.
Shortly after the Tahiti refresh came NVIDIA's move into display technology with G-Sync, a variable refresh rate feature that will work with upcoming monitors from ASUS and others as long as you have a GeForce Kepler GPU. The technology was damned impressive, but I am still waiting for NVIDIA to send over some panels for extended testing.
Later in October we were hit with the R9 290X, the Hawaii GPU that brought AMD back in the world of ultra-class single GPU card performance. It has produced stellar benchmarks and undercut the prices (then at least) of the GTX 780 and GTX TITAN. We tested it in both single and multi-GPU configurations and found that AMD had made some impressive progress in fixing its frame pacing issues, even with Eyefinity and 4K tiled displays.
NVIDIA dropped a driver release with ShadowPlay that allows gamers to record playback locally without a hit on performance. I posted a roundup of R9 280X cards which showed alternative coolers and performance ranges. We investigated the R9 290X Hawaii GPU and the claims that performance is variable and configurable based on fan speeds. Finally, the R9 290 (non-X model) was released this week to more fanfare than the 290X thanks to its nearly identical performance and $399 price tag.
And today, yet another release. NVIDIA's GeForce GTX 780 Ti takes the performance of the GK110 and fully unlocks it. The GTX TITAN uses one fewer SMX and the GTX 780 has three fewer SMX units so you can expect the GTX 780 Ti to, at the very least, become the fastest NVIDIA GPU available. But can it hold its lead over the R9 290X and validate its $699 price tag?
More of the same for a lot less cash
The week before Halloween, AMD unleashed a trick on the GPU world under the guise of the Radeon R9 290X and it was the fastest single GPU graphics card we had tested to date. With a surprising price point of $549, it was able to outperform the GeForce GTX 780 (and GTX TITAN in most cases) while under cutting the competitions price by $100. Not too bad!
Today's release might be more surprising (and somewhat confusing). The AMD Radeon R9 290 4GB card is based on the same Hawaii GPU with a few less compute units enabled (CUs) and an even more aggressive price and performance placement. Seriously, has AMD lost its mind?
Can a card with a $399 price tag cut into the same performance levels as the JUST DROPPED price of $499 for the GeForce GTX 780?? And, if so, what sacrifices are being made by users that adopt it? Why do so many of our introduction sentences end in question marks?
The R9 290 GPU - Hawaii loses a small island
If you are new to the Hawaii GPU and you missed our first review of the Radeon R9 290X from last month, you should probably start back there. The architecture is very similar to that of the HD 7000-series Tahiti GPUs with some modest changes to improve efficiency with the biggest jump in raw primitives per second to 4/clock over 2/clock.
The R9 290 is based on Hawaii though it has four fewer compute units (CUs) than the R9 290X. When I asked AMD if that meant there was one fewer CU per Shader Engine or if they were all removed from a single Engine, they refused to really answer. Instead, several "I'm not allowed to comment on the specific configuration" lines were given. This seems pretty odd as NVIDIA has been upfront about the dual options for its derivative GPU models. Oh well.
When AMD released the Radeon R9 290X last month, I came away from the review very impressed with the performance and price point the new flagship graphics card was presented with. My review showed that the 290X was clearly faster than the NVIDIA GeForce GTX 780 and (and that time) was considerably less expensive as well - a win-win for AMD without a doubt.
But there were concerns over a couple of aspects of the cards design. First was the temperature and, specifically, how AMD was okay with this rather large silicon hitting 95C sustained. Another concern, AMD has also included a switch at the top of the R9 290X to switch fan profiles. This switch essentially creates two reference defaults and makes it impossible for us to set a baseline of performance. These different modes only changed the maximum fan speed that the card was allowed to reach. Still, performance changed because of this setting thanks to the newly revised (and updated) AMD PowerTune technology.
We also saw, in our initial review, a large variation in clock speeds both from one game to another as well as over time (after giving the card a chance to heat up). This led me to create the following graph showing average clock speeds 5-7 minutes into a gaming session with the card set to the default, "quiet" state. Each test is over a 60 second span.
Clearly there is variance here which led us to more questions about AMD's stance. Remember when the Kepler GPUs launched. AMD was very clear that variance from card to card, silicon to silicon, was bad for the consumer as it created random performance deltas between cards with otherwise identical specifications.
When it comes to the R9 290X, though, AMD claims both the GPU (and card itself) are a customizable graphics solution. The customization is based around the maximum fan speed which is a setting the user can adjust inside the Catalyst Control Center. This setting will allow you to lower the fan speed if you are a gamer desiring a quieter gaming configuration while still having great gaming performance. If you are comfortable with a louder fan, because headphones are magic, then you have the option to simply turn up the maximum fan speed and gain additional performance (a higher average clock rate) without any actual overclocking.
ASUS R9 280X DirectCU II TOP
Earlier this month AMD took the wraps off of a revamped and restyled family of GPUs under the Radeon R9 and R7 brands. When I reviewed the R9 280X, essentially a lower cost version of the Radoen HD 7970 GHz Edition, I came away impressed with the package AMD was able to put together. Though there was no new hardware to really discuss with the R9 280X, the price drop placed the cards in a very aggressive position adjacent the NVIDIA GeForce line-up (including the GeForce GTX 770 and the GTX 760).
As a result, I fully expect the R9 280X to be a great selling GPU for those gamers with a mid-range budget of $300.
But another of the benefits of using an existing GPU architecture is the ability for board partners to very quickly release custom built versions of the R9 280X. Companies like ASUS, MSI, and Sapphire are able to have overclocked and custom-cooled alternatives to the 3GB $300 card, almost immediately, by simply adapting the HD 7970 PCB.
Today we are going to be reviewing a set of three different R9 280X cards: the ASUS DirectCU II, MSI Twin Frozr Gaming, and the Sapphire TOXIC.
ARM is Serious About Graphics
Ask most computer users from 10 years ago who ARM is, and very few would give the correct answer. Some well informed people might mention “Intel” and “StrongARM” or “XScale”, but ARM remained a shadowy presence until we saw the rise of the Smartphone. Since then, ARM has built up their brand, much to the chagrin of companies like Intel and AMD. Partners such as Samsung, Apple, Qualcomm, MediaTek, Rockchip, and NVIDIA have all worked with ARM to produce chips based on the ARMv7 architecture, with Apple being the first to release the first ARMv8 (64 bit) SOCs. The multitude of ARM architectures are likely the most shipped chips in the world, going from very basic processors to the very latest Apple A7 SOC.
The ARMv7 and ARMv8 architectures are very power efficient, yet provide enough performance to handle the vast majority of tasks utilized on smartphones and tablets (as well as a handful of laptops). With the growth of visual computing, ARM also dedicated itself towards designing competent graphics portions of their chips. The Mali architecture is aimed at being an affordable option for those without access to their own graphics design groups (NVIDIA, Qualcomm), but competitive with others that are willing to license their IP out (Imagination Technologies).
ARM was in fact one of the first to license out the very latest graphics technology to partners in the form of the Mali-T600 series of products. These modules were among the first to support OpenGL ES 3.0 (compatible with 2.0 and 1.1) and DirectX 11. The T600 architecture is very comparable to Imagination Technologies’ Series 6 and the Qualcomm Adreno 300 series of products. Currently NVIDIA does not have a unified mobile architecture in production that supports OpenGL ES 3.0/DX11, but they are adapting the Kepler architecture to mobile and will be licensing it to interested parties. Qualcomm does not license out Adreno after buying that group from AMD (Adreno is an anagram of Radeon).
ShadowPlay is NVIDIA's latest addition to their GeForce Experience platform. This feature allows their GPUs, starting with Kepler, to record game footage either locally or stream it online through Twitch.tv (in a later update). It requires Kepler GPUs because it is accelerated by that hardware. The goal is to constantly record game footage without any noticeable impact to performance; that way, the player can keep it running forever and have the opportunity to save moments after they happen.
Also, it is free.
I know that I have several gaming memories which come unannounced and leave undocumented. A solution like this is very exciting to me. Of course a feature on paper not the same as functional software in the real world. Thankfully, at least in my limited usage, ShadowPlay mostly lives up to its claims. I do not feel its impact on gaming performance. I am comfortable leaving it on at all times. There are issues, however, that I will get to soon.
This first impression is based on my main system running the 331.65 (Beta) GeForce drivers recommended for ShadowPlay.
- Intel Core i7-3770, 3.4 GHz
- NVIDIA GeForce GTX 670
- 16 GB DDR3 RAM
- Windows 7 Professional
- 1920 x 1080 @ 120Hz.
- 3 TB USB3.0 HDD (~50MB/s file clone).
The two games tested are Starcraft II: Heart of the Swarm and Battlefield 3.
A bit of a surprise
Okay, let's cut to the chase here: it's late, we are rushing to get our articles out, and I think you all would rather see our testing results NOW rather than LATER. The first thing you should do is read my review of the AMD Radeon R9 290X 4GB Hawaii graphics card which goes over the new architecture, new feature set, and performance in single card configurations.
Then, you should continue reading below to find out how the new XDMA, bridge-less CrossFire implementation actually works in both single panel and 4K (tiled) configurations.
A New CrossFire For a New Generation
CrossFire has caused a lot of problems for AMD in recent months (and a lot of problems for me as well). But, AMD continues to make strides in correcting the frame pacing issues associated with CrossFire configurations and the new R9 290X moves the bar forward.
Without the CrossFire bridge connector on the 290X, all of the CrossFire communication and data transfer occurs over the PCI Express bus that connects the cards to the entire system. AMD claims that this new XDMA interface was designed for Eyefinity and UltraHD resolutions (which were the subject of our most recent article on the subject). By accessing the memory of the GPU through PCIe AMD claims that it can alleviate the bandwidth and sync issues that were causing problems with Eyefinity and tiled 4K displays.
Even better, this updated version of CrossFire is said to compatible with the frame pacing updates to the Catalyst driver to improve multi-GPU performance experiences for end users.
When an extra R9 290X accidentally fell into my lap, I decided to take it for a spin. And if you have followed my graphics testing methodology in the past year then you'll understand the important of these tests.
A slightly new architecture
Last month AMD brought media, analysts, and customers out to Hawaii to talk about a new graphics chip coming out this year. As you might have guessed based on the location: the code name for this GPU was in fact, Hawaii. It was targeted at the high end of the discrete graphics market to take on the likes of the GTX 780 and GTX TITAN from NVIDIA.
Earlier this month we reviewed the AMD Radeon R9 280X, R9 270X, and the R7 260X. None of these were based on that new GPU. Instead, these cards were all rebrands and repositionings of existing hardware in the market (albeit at reduced prices). Those lower prices made the R9 280X one of our favorite GPUs of the moment as it offers performance per price points currently unmatched by NVIDIA.
But today is a little different, today we are talking about a much more expensive product that has to live up to some pretty lofty goals and ambitions set forward by the AMD PR and marketing machine. At $549 MSRP, the new AMD Radeon R9 290X will become the flagship of the Radeon brand. The question is: to where does that ship sail?
The AMD Hawaii Architecture
To be quite upfront about it, the Hawaii design is very similar to that of the Tahiti GPU from the Radeon HD 7970 and R9 280X cards. Based on the same GCN (Graphics Core Next) architecture AMD assured us would be its long term vision, Hawaii ups the ante in a few key areas while maintaining the same core.
Hawaii is built around Shader Engines, of which the R9 290X has four. Each of these includes 11 CU (compute units) which hold 4 SIMD arrays each. Doing the quick math brings us to a total stream processor count of 2,816 on the R9 290X.
Our Legacys Influence
We are often creatures of habit. Change is hard. And often times legacy systems that have been in place for a very long time can shift and determine the angle at which we attack new problems. This happens in the world of computer technology but also outside the walls of silicon and the results can be dangerous inefficiencies that threaten to limit our advancement in those areas. Often our need to adapt new technologies to existing infrastructure can be blamed for stagnant development.
Take the development of the phone as an example. The pulse based phone system and the rotary dial slowed the implementation of touch dial phones and forced manufacturers to include switches to select between pulse and tone based dialing options on phones for decades.
Perhaps a more substantial example is that of the railroad system that has based the track gauge (width between the rails) on the transportation methods that existed before the birth of Christ. Horse drawn carriages pulled by two horses had an axle gap of 4 feet 8 inches in the 1800s and thus the first railroads in the US were built with a track gauge of 4 feet 8 inches. Today, the standard rail track gauge remains 4 feet 8 inches despite the fact that a wider gauge would allow for more stability of larger cargo loads and allow for higher speed vehicles. But the cost of updating the existing infrastructure around the world would be so cost prohibitive that it is likely we will remain with that outdated standard.
What does this have to do with PC hardware and why am I giving you an abbreviated history lesson? There are clearly some examples of legacy infrastructure limiting our advancement in hardware development. Solid state drives are held back by the current SATA based storage interface though we are seeing movements to faster interconnects like PCI Express to alleviate this. Some compute tasks are limited by the “infrastructure” of standard x86 processor cores and the move to GPU compute has changed the direction of these workloads dramatically.
There is another area of technology that could be improved if we could just move past an existing way of doing things. Displays.
The AMD Radeon R9 280X
Today marks the first step in an introduction of an entire AMD Radeon discrete graphics product stack revamp. Between now and the end of 2013, AMD will completely cycle out Radeon HD 7000 cards and replace them with a new branding scheme. The "HD" branding is on its way out and it makes sense. Consumers have moved on to UHD and WQXGA display standards; HD is no longer extraordinary.
But I want to be very clear and upfront with you: today is not the day that you’ll learn about the new Hawaii GPU that AMD promised would dominate the performance per dollar metrics for enthusiasts. The Radeon R9 290X will be a little bit down the road. Instead, today’s review will look at three other Radeon products: the R9 280X, the R9 270X and the R7 260X. None of these products are really “new”, though, and instead must be considered rebrands or repositionings.
There are some changes to discuss with each of these products, including clock speeds and more importantly, pricing. Some are specific to a certain model, others are more universal (such as updated Eyefinity display support).
Let’s start with the R9 280X.
AMD Radeon R9 280X – Tahiti aging gracefully
The AMD Radeon R9 280X is built from the exact same ASIC (chip) that powers the previous Radeon HD 7970 GHz Edition with a few modest changes. The core clock speed of the R9 280X is actually a little bit lower at reference rates than the Radeon HD 7970 GHz Edition by about 50 MHz. The R9 280X GPU will hit a 1.0 GHz rate while the previous model was reaching 1.05 GHz; not much a change but an interesting decision to be made for sure.
Because of that speed difference the R9 280X has a lower peak compute capability of 4.1 TFLOPS compared to the 4.3 TFLOPS of the 7970 GHz. The memory clock speed is the same (6.0 Gbps) and the board power is the same, with a typical peak of 250 watts.
Everything else remains the same as you know it on the HD 7970 cards. There are 2048 stream processors in the Tahiti version of AMD’s GCN (Graphics Core Next), 128 texture units and 32 ROPs all being pushed by a 384-bit GDDR5 memory bus running at 6.0 GHz. Yep, still with a 3GB frame buffer.
A new generation of Software Rendering Engines.
We have been busy with side projects, here at PC Perspective, over the last year. Ryan has nearly broken his back rating the frames. Ken, along with running the video equipment and "getting an education", developed a hardware switching device for Wirecase and XSplit.
My project, "Perpetual Motion Engine", has been researching and developing a GPU-accelerated software rendering engine. Now, to be clear, this is just in very early development for the moment. The point is not to draw beautiful scenes. Not yet. The point is to show what OpenGL and DirectX does and what limits are removed when you do the math directly.
Errata: BioShock uses a modified Unreal Engine 2.5, not 3.
In the above video:
- I show the problems with graphics APIs such as DirectX and OpenGL.
- I talk about what those APIs attempt to solve, finding color values for your monitor.
- I discuss the advantages of boiling graphics problems down to general mathematics.
- Finally, I prove the advantages of boiling graphics problems down to general mathematics.
I would recommend watching the video, first, before moving forward with the rest of the editorial. A few parts need to be seen for better understanding.