A third primary processor
As the Hot Chips conference begins in Cupertino this week, Qualcomm is set to divulge another set of information about the upcoming Snapdragon 820 processor. Earlier this month the company revealed details about the Adreno 5xx GPU architecture, showcasing improved performance and power efficiency while also adding a new Spectra 14-bit image processor. Today we shift to what Qualcomm calls the “third pillar in the triumvirate of programmable processors” that make up the Snapdragon SoC. The Hexagon DSP (digital signal processor), introduced initially by Qualcomm in 2004, has gone through a massive architecture shift and even programmability shift over the last 10 years.
Qualcomm believes that building a balanced SoC for mobile applications is all about heterogeneous computing with no one processor carrying the entire load. The majority of the work that any modern Snapdragon processor must handle goes through the primary CPU cores, the GPU or the DSP. We learned about upgrades to the Adreno 5xx series for the Snapdragon 820 and we are promised information about Kryo CPU architecture soon as well. But the Hexagon 600-series of DSPs actually deals with some of the most important functionality for smartphones and tablets: audio, voice, imaging and video.
Interestingly, Qualcomm opened up the DSP to programmability just four years ago, giving developers the ability to write custom code and software to take advantages of the specific performance capabilities that the DSP offers. Custom photography, videography and sound applications could benefit greatly in terms of performance and power efficiency if utilizing the QC DSP rather than the primary system CPU or GPU. As of this writing, Qualcomm claims there are “hundreds” of developers actively writing code targeting its family of Hexagon processors.
The Hexagon DSP in Snapdragon 820 consists of three primary partitions. The main compute DSP works in conjunction with the GPU and CPU cores and will do much of the heavy lifting for encompassed workloads. The modem DSP aids the cellular modem in communication throughput. The new guy here is the lower power DSP in the Low Power Island (LPI) that shifts how always-on sensors can communicate with the operating system.
Core and Interconnect
The Skylake architecture is Intel’s first to get a full release on the desktop in more than two years. While that might not seem like a long time in the grand scheme of technology, for our readers and viewers that is a noticeable change and shift from recent history that Intel has created with the tick-tock model of releases. Yes, Broadwell was released last year and was solid product, but Intel focused almost exclusively on the mobile platforms (notebooks and tablets) with it. Skylake will be much more ubiquitous and much more quickly than even Haswell.
Skylake represents Intel’s most scalable architecture to date. I don’t mean only frequency scaling, though that is an important part of this design, but rather in terms of market segment scaling. Thanks to brilliant engineering and design from Intel’s Israeli group Intel will be launching Skylake designs ranging from 4.5 watt TDP Core M solutions all the way up to the 91 watt desktop processors that we have already reviewed in the Core i7-6700K. That’s a range that we really haven’t seen before and in the past Intel has depended on the Atom architecture to make up ground on the lowest power platforms. While I don’t know for sure if Atom is finally trending towards the dodo once Skylake’s reign is fully implemented, it does make me wonder how much life is left there.
Scalability also refers to the package size – something that ensures that the designs the engineers created can actually be built and run in the platform segments they are targeting. Starting with the desktop designs for LGA platforms (DIY market) that fits on a 1400 mm2 design on the 91 watt TDP implementation Intel is scaling all the way down to 330 mm2 in a BGA1515 package for the 4.5 watt TDP designs. Only with a total product size like that can you hope to get Skylake in a form factor like the Compute Stick – which is exactly what Intel is doing. And note that the smaller packages require the inclusion of the platform IO chip as well, something that H- and S-series CPUs can depend on the motherboard to integrate.
Finally, scalability will also include performance scaling. Clearly the 4.5 watt part will not offer the user the same performance with the same goals as the 91 watt Core i7-6700K. The screen resolution, attached accessories and target applications allow Intel to be selective about how much power they require for each series of Skylake CPUs.
The fundamental design theory in Skylake is very similar to what exists today in Broadwell and Haswell with a handful of significant and hundreds of minor change that make Skylake a large step ahead of previous designs.
This slide from Julius Mandelblat, Intel Senior Principle Engineer, shows a higher level overview of the entirety of the consumer integration of Skylake. You can see that Intel’s goals included a bigger and wider core design, higher frequency, improved right architecture and fabric design and more options for eDRAM integration. Readers of PC Perspective will already know that Skylake supports both DDR3L and DDR4 memory technologies but the inclusion of the camera ISP is new information for us.
I knew that the move to DirectX 12 was going to be a big shift for the industry. Since the introduction of the AMD Mantle API along with the Hawaii GPU architecture we have been inundated with game developers and hardware vendors talking about the potential benefits of lower level APIs, which give more direct access to GPU hardware and enable more flexible threading for CPUs to game developers and game engines. The results, we were told, would mean that your current hardware would be able to take you further and future games and applications would be able to fundamentally change how they are built to enhance gaming experiences tremendously.
I knew that the reader interest in DX12 was outstripping my expectations when I did a live blog of the official DX12 unveil by Microsoft at GDC. In a format that consisted simply of my text commentary and photos of the slides that were being shown (no video at all), we had more than 25,000 live readers that stayed engaged the whole time. Comments and questions flew into the event – more than me or my staff could possible handle in real time. It turned out that gamers were indeed very much interested in what DirectX 12 might offer them with the release of Windows 10.
Today we are taking a look at the first real world gaming benchmark that utilized DX12. Back in March I was able to do some early testing with an API-specific test that evaluates the overhead implications of DX12, DX11 and even AMD Mantle from Futuremark and 3DMark. This first look at DX12 was interesting and painted an amazing picture about the potential benefits of the new API from Microsoft, but it wasn’t built on a real game engine. In our Ashes of the Singularity benchmark testing today, we finally get an early look at what a real implementation of DX12 looks like.
And as you might expect, not only are the results interesting, but there is a significant amount of created controversy about what those results actually tell us. AMD has one story, NVIDIA another and Stardock and the Nitrous engine developers, yet another. It’s all incredibly intriguing.
It comes after 8, but before 10
As the week of Intel’s Developer Forum (IDF) begins, you can expect to see a lot of information about Intel’s 6th Generation Core architecture, codenamed Skylake, finally revealed. When I posted my review of the Core i7-6700K, the first product based on that architecture to be released in any capacity, I was surprised that Intel was willing to ship product without the normal amount of background information for media and developers. Rather than give us the details and then ship product, which has happened for essentially every consumer product release I have been a part of, Intel did the reverse: ship a consumer friendly CPU and then promise to tell us how it all works later in the month at IDF.
Today I came across a document posted on Intel’s website that dives into very specific detail on the new Gen9 graphics and compute architecture of Skylake. Details on the Core architecture changes are not present, and instead we are given details on how the traditional GPU portion of the SoC has changed. To be clear: I haven’t had any formal briefing from Intel on this topic or anything surrounding the architecture of Skylake or the new Gen9 graphics system but I wanted to share the details we found available. I am sure we’ll learn more this week as IDF progresses so I will update this story where necessary.
What Intel calls Processor Graphics is what we used to call simply integrated graphics for the longest time. The purpose and role of processor graphics has changed drastically over the years and it is now not only responsible for 3D graphics rendering but compute, media and display capabilities of the Intel Skylake SoC (when discrete add-in graphics is not used). The architecture document used to source this story focuses on Gen9 graphics, the compute architecture utilized in the latest Skylake CPUs. The Intel HD Graphics 530 on the Core i7-6700K / Core i5-6600K is the first product released and announced using Gen9 graphics and is also the first to adopt Intel’s new 3-digit naming scheme.
This die shot of the Core i7-6700K shows the increased size and prominence of the Gen9 graphics in the overall SoC design. Containing four traditional x86 CPU cores and 1 “slice” implementation of Gen9 graphics (with three visible sub-slices we’ll describe below), this is not likely to be the highest performing iteration of the latest Intel HD Graphics technology.
Like the Intel processors before it, the Skylake design utilizes a ring bus architecture to connect the different components of the SoC. This bi-directional interconnect has a 32-byte wide data bus and connects to multiple “agents” on the CPU. Each individual CPU core is considered its own agent while the Gen9 compute architecture is considered one complete agent. The system agent bundles the DRAM memory, the display controller, PCI Express and other I/O interface that communicate with the rest of the PC. Any off-chip memory requests and transactions occur through this bus while on-chip data transfers tend to be handled differently.
Subject: Graphics Cards, Processors, Mobile | August 12, 2015 - 11:30 AM | Ryan Shrout
Tagged: snapdragon 820, snapdragon, siggraph 2015, Siggraph, qualcomm, adreno 530, adreno
Despite the success of the Snapdragon 805 and even the 808, Qualcomm’s flagship Snapdragon 810 SoC had a tumultuous lifespan. Rumors and stories about the chip and an inability to run in phone form factors without overheating and/or draining battery life were rampant, despite the company’s insistence that the problem was fixed with a very quick second revision of the part. There are very few devices that used the 810 and instead we saw more of the flagship smartphones uses the slightly cut back SD 808 or the SD 805.
Today at Siggraph Qualcomm starts the reveal of a new flagship SoC, Snapdragon 820. As the event coinciding with launch is a graphics-specific show, QC is focusing on a high level overview of the graphics portion of the Snapdragon 820, the updated Adreno 5xx architecture and associated designs and a new camera image signal processor (ISP) aiming to improve quality of photos and recording on our mobile devices.
A modern SoC from Qualcomm features many different processors working in tandem to impact the user experience on the device. While the only details we are getting today focus around the Adreno 530 GPU and Spectra ISP, other segments like connectivity (wireless), DSP, video processing and digital signal processing are important parts of the computing story. And we are well aware that Qualcomm is readying its own 64-bit processor architecture for the Kryo CPU rather than implementing the off-the-shelf cores from ARM used in the 810.
We also know that Qualcomm is targeting a “leading edge” FinFET process technology for SD 820 and though we haven’t been able to confirm anything, it looks very like that this chip will be built on the Samsung 14nm line that also built the Exynos 7420.
But over half of the processing on the upcoming Snapdragon 820 fill focus on visual processing, from graphics to gaming to UI animations to image capture and video output, this chip’s die will be dominated by high performance visuals.
Qualcomm’s lists of target goals for SD 820 visuals reads as you would expect: wanting perfection in every area. Wouldn’t we all love a phone or tablet that takes perfect photos each time, always focusing on the right things (or everything) with exceptional low light performance? Though a lesser known problem for consumers, having accurate color reproduction from capture, through processing and to the display would be a big advantage. And of course, we all want graphics performance that impresses and a user interface that is smooth and reliable while enabling NEW experience that we haven’t even thought of in the mobile form factor. Qualcomm thinks that Snapdragon 820 will be able to deliver on all of that.
Subject: Processors | August 11, 2015 - 10:39 PM | Jeremy Hellstrom
Tagged: skylake-u, Intel
Fanless Tech just posted slides of Skylake-U the ultraportable version of Skylake, all of which have an impressively low TDP of 15W which can be reduced to either 10W or in some cases all the way down to 7.5W. As they have done previously all are BGA socketed which means you will not be able to upgraded nor are you likely to see them in desktops, not necessarily a bad thing for this segment of the mobile market but certainly worth noting.
There will be two i7 models and two i5 along with a single i3 version, the top models of which, the Core i7-6600U and Core i5-6300U sport a slightly increased frequency and support for vPro. Those two models, along with the i7-6500U and i5-6200U will have the Intel HD graphics 520 with frequencies of 300/1050 for the i7's and 300/1000 for the i5 and i3 chips
Along with the Core models will come a single Pentium chip, the 4405U and a pair of Celerons, the 3955U and 3855U. They will have HD510 graphics, clocks of 300/950 or 300/900 for the Celerons and you will see slight reductions in PCIe and storage subsystems on teh 4405U and 3855U. The naming scheme is less confusing that some previous generations, a boon for those with family or friends looking for a new laptop who are perhaps not quite as obsessed with processors as we are.
Subject: Graphics Cards, Processors, Mobile, Shows and Expos | August 10, 2015 - 01:01 PM | Scott Michaud
Tagged: vulkan, spir, siggraph 2015, Siggraph, opengl sc, OpenGL ES, opengl, opencl, Khronos
When the Khronos Group announced Vulkan at GDC, they mentioned that the API is coming this year, and that this date is intended to under promise and over deliver. Recently, fans were hoping that it would be published at SIGGRAPH, which officially begun yesterday. Unfortunately, Vulkan has not released. It does hold a significant chunk of the news, however. Also, it's not like DirectX 12 is holding a commanding lead at the moment. The headers were public only for a few months, and the code samples are less than two weeks old.
The organization made announcements for six products today: OpenGL, OpenGL ES, OpenGL SC, OpenCL, SPIR, and, as mentioned, Vulkan. They wanted to make their commitment clear, to all of their standards. Vulkan is urgent, but some developers will still want the framework of OpenGL. Bind what you need to the context, then issue a draw and, if you do it wrong, the driver will often clean up the mess for you anyway. The briefing was structure to be evident that it is still in their mind, which is likely why they made sure three OpenGL logos greeted me in their slide deck as early as possible. They are also taking and closely examining feedback about who wants to use Vulkan or OpenGL, and why.
As for Vulkan, confirmed platforms have been announced. Vendors have committed to drivers on Windows 7, 8, 10, Linux, including Steam OS, and Tizen (OSX and iOS are absent, though). Beyond all of that, Google will accept Vulkan on Android. This is a big deal, as Google, despite its open nature, has been avoiding several Khronos Group standards. For instance, Nexus phones and tablets do not have OpenCL drivers, although Google isn't stopping third parties from rolling it into their devices, like Samsung and NVIDIA. Direct support of Vulkan should help cross-platform development as well as, and more importantly, target the multi-core, relatively slow threaded processors of those devices. This could even be of significant use for web browsers, especially in sites with a lot of simple 2D effects. Google is also contributing support from their drawElements Quality Program (dEQP), which is a conformance test suite that they bought back in 2014. They are going to expand it to Vulkan, so that developers will have more consistency between devices -- a big win for Android.
While we're not done with Vulkan, one of the biggest announcements is OpenGL ES 3.2 and it fits here nicely. At around the time that OpenGL ES 3.1 brought Compute Shaders to the embedded platform, Google launched the Android Extension Pack (AEP). This absorbed OpenGL ES 3.1 and added Tessellation, Geometry Shaders, and ASTC texture compression to it. It was also more tension between Google and cross-platform developers, feeling like Google was trying to pull its developers away from Khronos Group. Today, OpenGL ES 3.2 was announced and includes each of the AEP features, plus a few more (like “enhanced” blending). Better yet, Google will support it directly.
Next up are the desktop standards, before we finish with a resurrected embedded standard.
OpenGL has a few new extensions added. One interesting one is the ability to assign locations to multi-samples within a pixel. There is a whole list of sub-pixel layouts, such as rotated grid and Poisson disc. Apparently this extension allows developers to choose it, as certain algorithms work better or worse for certain geometries and structures. There were probably vendor-specific extensions for a while, but now it's a ratified one. Another extension allows “streamlined sparse textures”, which helps manage data where the number of unpopulated entries outweighs the number of populated ones.
OpenCL 2.0 was given a refresh, too. It contains a few bug fixes and clarifications that will help it be adopted. C++ headers were also released, although I cannot comment much on it. I do not know the state that OpenCL 2.0 was in before now.
And this is when we make our way back to Vulkan.
SPIR-V, the code that runs on the GPU (or other offloading device, including the other cores of a CPU) in OpenCL and Vulkan is seeing a lot of community support. Projects are under way to allow developers to write GPU code in several interesting languages: Python, .NET (C#), Rust, Haskell, and many more. The slide lists nine that Khronos Group knows about, but those four are pretty interesting. Again, this is saying that you can write code in the aforementioned languages and have it run directly on a GPU. Curiously missing is HLSL, and the President of Khronos Group agreed that it would be a useful language. The ability to cross-compile HLSL into SPIR-V means that shader code written for DirectX 9, 10, 11, and 12 could be compiled for Vulkan. He expects that it won't take long for a project to start, and might already be happening somewhere outside his Google abilities. Regardless, those who are afraid to program in the C-like GLSL and HLSL shading languages might find C# and Python to be a bit more their speed, and they seem to be happening through SPIR-V.
As mentioned, we'll end on something completely different.
For several years, the OpenGL SC has been on hiatus. This group defines standards for graphics (and soon GPU compute) in “safety critical” applications. For the longest time, this meant aircraft. The dozens of planes (which I assume meant dozens of models of planes) that adopted this technology were fine with a fixed-function pipeline. It has been about ten years since OpenGL SC 1.0 launched, which was based on OpenGL ES 1.0. SC 2.0 is planned to launch in 2016, which will be based on the much more modern OpenGL ES 2 and ES 3 APIs that allow pixel and vertex shaders. The Khronos Group is asking for participation to direct SC 2.0, as well as a future graphics and compute API that is potentially based on Vulkan.
The devices that this platform intends to target are: aircraft (again), automobiles, drones, and robots. There are a lot of ways that GPUs can help these devices, but they need a good API to certify against. It needs to withstand more than an Ouya, because crashes could be much more literal.
Subject: Processors | August 8, 2015 - 09:55 PM | Scott Michaud
Tagged: Skylake, Intel, delid, CPU die, cpu, Core i7-6700K
PC Watch, a Japanese computer hardware website, acquired at least one Skylake i7-6700K and removed the heatspreader. With access to the bare die, they took some photos and tested a few thermal compound replacements, which quantifies how good (or bad) Intel's default thermal grease is. As evidenced by the launch of Ivy Bridge and, later, Devil's Canyon, the choice of thermal interface between the die and the lid can make a fairly large difference in temperatures and overclocking.
Image Credit: PC Watch
They chose the vice method for the same reason that Morry chose this method in his i7-4770k delid article last year. This basically uses a slight amount of torque and external pressure or shock to pop the lid off the processor. Despite how it looks, this is considered to be less traumatic than using a razer blade to cut the seal, because human hands are not the most precise instruments and a slight miss could damage the PCB. PC Watch, apparently, needed to use a wrench to get enough torque on the vice, which is transferred to the processor as pressure.
Image Credit: PC Watch
Of course, Intel could always offer enthusiasts with choices in thermal compounds before they put the lid on, which would be safest. How about that, Intel?
Image Credit: PC Watch
With the lid off, PC Watch mentioned that the thermal compound seems to be roughly the same as Devil's Canyon, which is quite good. They also noticed that the PCB is significantly more thin than Haswell, dropping in thickness from about 1.1mm to about 0.8mm. For some benchmarks, they tested it with the stock interface, an aftermarket solution called Prolimatech PK-3, and a liquid metal alloy called Coollaboratory Liquid Pro.
Image Credit: PC Watch
At 4.0 GHz, PK-3 dropped the temperature by about 4 degrees Celsius, while Liquid Metal knocked it down 16 degrees. At 4.6 GHz, PK-3 continued to give a delta of about 4 degrees, while Liquid Metal widened its gap to 20 degrees. It reduced an 88 C temperature to 68 C!
Image Credit: PC Watch
There are obviously limitations to how practical this is. If you were concerned about thermal wear on your die, you probably wouldn't forcibly remove its heatspreader from its PCB to acquire it. That would be like performing surgery on yourself to remove your own appendix, which wasn't inflamed, just in case. Also, from an overclocking standpoint, heat doesn't scale with frequency. Twenty degrees is a huge gap, but even a hundred MHz could eat it up, depending on your die.
It's still interesting for those who try, though.
Subject: Processors | August 5, 2015 - 07:20 PM | Jeremy Hellstrom
Tagged: sunrise point, Skylake, Intel, ddr4, Core i7-6700K, core i7, 6700k, 14nm
By now you have read through Ryan's review of the new i7-6700 and the ASUS Z170-A as well as the related videos and testing, if not we will wait for you to flog yourself in punishment and finish reading the source material. Now that you are ready, take a look at what some of the other sites thought about the new Skylake chip and Sunrise Point chipset. For instance [H]ard|OCP managed to beat Ryan's best overclock, hitting 4.7GHz/3600MHz at 1.32v vCore with some toasty but acceptable CPU temperatures. The full review is worth looking for and if some of the rumours going around are true you should take H's advice, if you think you want one buy it now.
"Today we finally get to share with you our Intel Skylake experiences. As we like to, we are going to focus on Instructions Per Clock / IPC and overclocking this new CPU architecture. We hope to give our readers a definitive answer to whether or not it is time to make the jump to a new desktop PC platform."
Here are some more Processor articles from around the web:
- Intel's Core i7-6700K 'Skylake' @ The Tech Report
- Asus' Z170-A motherboard @ The Tech Report
- Intel Core i7-6700K & i5-6600K Skylake CPU @ Kitguru
- Asus Maximus VIII Hero @ Kitguru
- A Preview Of Intel’s First Skylake Processors & Z107 Chipset @ Techgage
- Intel Core I7 6700K Review, Skylake is Falling! @ Bjorn3d
- Intel 6th Generation Core i7 6700K Review @ OCC
Light on architecture details
Our Intel Skylake launch coverage is intense! Make sure you hit up all the stories and videos that are interesting for you!
- The Intel Core i7-6700K Review - Skylake First for Enthusiasts (Video)
- Skylake vs. Sandy Bridge: Discrete GPU Showdown (Video)
- ASUS Z170-A Motherboard Preview
- Intel Skylake / Z170 Rapid Storage Technology Tested - PCIe and SATA RAID
The Intel Skylake architecture has been on our radar for quite a long time as Intel's next big step in CPU design. Through leaks and some official information discussed by Intel over the past few months, we know at least a handful of details: DDR4 memory support, 14nm process technology, modest IPC gains and impressive GPU improvements. But the details have remained a mystery on how the "tock" of Skylake on the 14nm process technology will differ from Broadwell and Haswell.
Interestingly, due to some shifts in how Intel is releasing Skylake, we are going to be doing a review today with very little information on the Skylake architecture and design (at least officially). While we are very used to the company releasing new information at the Intel Developer Forum along with the launch of a new product, Intel has instead decided to time the release of the first Skylake products with Gamescom in Cologne, Germany. Parts will go on sale today (August 5th) and we are reviewing a new Intel processor without the background knowledge and details that will be needed to really explain any of the changes or differences in performance that we see. It's an odd move honestly, but it has some great repercussions for the enthusiasts that read PC Perspective: Skylake will launch first as an enthusiast-class product for gamers and DIY builders.
For many of you this won't change anything. If you are curious about the performance of the new Core i7-6700K, power consumption, clock for clock IPC improvements and anything else that is measurable, then you'll get exactly what you want from today's article. If you are a gear-head that is looking for more granular details on how the inner-workings of Skylake function, you'll have to wait a couple of weeks longer - Intel plans to release that information on August 18th during IDF.
So what does the addition of DDR4 memory, full range base clock manipulation and a 4.0 GHz base clock on a brand new 14nm architecture mean for users of current Intel or AMD platforms? Also, is it FINALLY time for users of the Core i7-2600K or older systems to push that upgrade button? (Let's hope so!)