Author:
Manufacturer: AMD

Hybrid CrossFire that actually works

The road to redemption for AMD and its driver team has been a tough one.  Since we first started to reveal the significant issues with AMD's CrossFire technology back in January of 2013 the Catalyst driver team has been hard at work on a fix, though I will freely admit it took longer to convince them that the issue was real than I would have liked.  We saw the first steps of the fix released in August of 2013 with the release of the Catalyst 13.8 beta driver.  It supported DX11 and DX10 games and resolutions of 2560x1600 and under (no Eyefinity support) but was obviously still less than perfect.  

In October with the release of AMD's latest Hawaii GPU the company took another step by reorganizing the internal architecture of CrossFire on the chip level with XDMA.  The result was frame pacing that worked on the R9 290X and R9 290 in all resolutions, including Eyefinity, though still left out older DX9 titles.  

One thing that had not been addressed, at least not until today, was the issues that surrounded AMD's Hybrid CrossFire technology, now known as Dual Graphics.  This is the ability for an AMD APU with integrated Radeon graphics to pair with a low cost discrete GPU to improve graphics performance and gaming experiences.  Recently over at Tom's Hardware they discovered that Dual Graphics suffered from the exact same scaling issues as standard CrossFire; frame rates in FRAPS looked good but the actually perceived frame rate was much lower.

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A little while ago a new driver made its way into my hands under the name of Catalyst 13.35 Beta X, a driver that promised to enable Dual Graphics frame pacing with Kaveri and R7 graphics cards.  As you'll see in the coming pages, the fix definitely is working.  And, as I learned after doing some more probing, the 13.35 driver is actually a much more important release than it at first seemed.  Not only is Kaveri-based Dual Graphics frame pacing enabled, but Richland and Trinity are included as well.  And even better, this driver will apparently fix resolutions higher than 2560x1600 in desktop graphics as well - something you can be sure we are checking on this week!

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Just as we saw with the first implementation of Frame Pacing in the Catalyst Control Center, with the 13.35 Beta we are using today you'll find a new set of options in the Gaming section to enable or disable Frame Pacing.  The default setting is On; which makes me smile inside every time I see it.

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The hardware we are using is the same basic setup we used in my initial review of the AMD Kaveri A8-7600 APU review.  That includes the A8-7600 APU, an Asrock A88X mini-ITX motherboard, 16GB of DDR3 2133 MHz memory and a Samsung 840 Pro SSD.  Of course for our testing this time we needed a discrete card to enable Dual Graphics and we chose the MSI R7 250 OC Edition with 2GB of DDR3 memory.  This card will run you an additional $89 or so on Amazon.com.  You could use either the DDR3 or GDDR5 versions of the R7 250 as well as the R7 240, but in our talks with AMD they seemed to think the R7 250 DDR3 was the sweet spot for the CrossFire implementation.

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Both the R7 250 and the A8-7600 actually share the same number of SIMD units at 384, otherwise known as 384 shader processors or 6 Compute Units based on the new nomenclature that AMD is creating.  However, the MSI card is clocked at 1100 MHz while the GPU portions of the A8-7600 APU are running at only 720 MHz. 

So the question is, has AMD truly fixed the issues with frame pacing with Dual Graphics configurations, once again making the budget gamer feature something worth recommending?  Let's find out!

Continue reading our look at Dual Graphics Frame Pacing with the Catalyst 13.35 Beta Driver!!

Podcast #283 - AMD Kaveri APU Launch, Gigabyte's New Slim Gaming Notebook, and CES 2014 Wrapup!

Subject: General Tech | January 15, 2014 - 09:26 PM |
Tagged: video, R9 290X, podcast, msi, Kaveri, gsync, gigabyte, freesync, benq, amd, a8-7600, 290x

PC Perspective Podcast #283 - 01/16/2014

Join us this week as we discuss the AMD Kaveri APU Launch, Gigabyte's New Slim Gaming Notebook, and CES 2014 Wrapup!

You can subscribe to us through iTunes and you can still access it directly through the RSS page HERE.

The URL for the podcast is: http://pcper.com/podcast - Share with your friends!

  • iTunes - Subscribe to the podcast directly through the iTunes Store
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  • MP3 - Direct download link to the MP3 file

Hosts: Ryan Shrout, Jeremy Hellstrom, Josh Walrath and Allyn Malventano

 
Program length: 1:13:50

AMD announces Garlic and Onion flavours on their first HSA chips

Subject: Processors | January 14, 2014 - 11:52 AM |
Tagged: a10-6700, a8-6500, a8-7600, amd, APU, hsa, i3-4330, Kaveri

Not only are the first Kaveri reviews arriving today, the A10-7850K is up for sale on both NewEgg and Amazon and the A10-7700K is available on NewEgg.  This new part, at 45W competes favourably with the previous 100W Trinity APU in most tests and when Ryan boosted it to 65W it gained a little more.  The Steamroller cores have been updated but not in a way that has a huge effect on CPU performance, on the other hand the 384 SIMD units composing the GPU portion of this chip are quite impressive, 1080p gaming of current generation titles is possible on this chip and we haven't seen it's big brother with 512 SIMD units yet.  In the Tech Report's review you can see that BF4 is playable on this chip and this is not the Mantle version optimized for AMD's new architecture.  It is also a pity that Thief was unavailable to see just what TrueAudio is capable of.  Unfortunately this chip will not find its home in gamers dream machines, that is simply not where AMD is targeting its CPUs.  However, for SFF systems that need to be energy efficient and where a discrete GPU is to big to fit Kaveri will usher in a new level of performance.

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"AMD's next-generation APU packs in a ton of innovation, including updated "Steamroller" CPU cores, GCN graphics, and advanced HSA features. But is it enough to restore AMD's competitiveness in desktop processors?"

Here are some more Processor articles from around the web:

Processors

Author:
Subject: Processors
Manufacturer: AMD

The AMD Kaveri Architecture

Kaveri: AMD’s New Flagship Processor

How big is Kaveri?  We already know the die size of it, but what kind of impact will it have on the marketplace?  Has AMD chosen the right path by focusing on power consumption and HSA?  Starting out an article with three questions in a row is a questionable tactic for any writer, but these are the things that first come to mind when considering a product the likes of Kaveri.  I am hoping we can answer a few of these questions by the end of this article, but alas it seems as though the market will have the final say as to how successful this new architecture is.

AMD has been pursuing the “Future is Fusion” line for several years, but it can be argued that Kaveri is truly the first “Fusion” product that completes the overall vision for where AMD wants to go.  The previous several generations of APUs were initially not all that integrated in a functional sense, but the complexity and completeness of that integration has been improved upon with each iteration.  Kaveri takes this integration to the next step, and one which fulfills the promise of a truly heterogeneous computing solution.  While AMD has the hardware available, we have yet to see if the software companies are willing to leverage the compute power afforded by a robust and programmable graphics unit powered by AMD’s GCN architecture.

(Editor's Note: The following two pages were written by our own Josh Walrath, dicsussing the technology and architecture of AMD Kaveri.  Testing and performance analysis by Ryan Shrout starts on page 3.)

Process Decisions

The first step in understanding Kaveri is taking a look at the process technology that AMD is using for this particular product.  Since AMD divested itself of their manufacturing arm, they have had to rely on GLOBALFOUNDRIES to produce nearly all of their current CPUs and APUs.  Bulldozer, Piledriver, Llano, Trinity, and Richland based parts were all produced on GF’s 32 nm PD-SOI process.  The lower power APUs such as Brazos and Kabini have been produced by TSMC on their 40 nm and 28 nm processes respectively.

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Kaveri will take a slightly different approach here.  It will be produced by GLOBALFOUNDRIES, but it will forego the SOI and utilize a bulk silicon process.  28 nm HKMG is very common around the industry, but few pure play foundries were willing to tailor their process to the direct needs of AMD and the Kaveri product.  GF was able to do such a thing.  APUs are a different kind of animal when it comes to fabrication, primarily because the two disparate units require different characteristics to perform at the highest efficiency.  As such, compromises had to be made.

Continue reading our review of the new AMD Kaveri A8-7600 APU!!