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VR-Zone.com - Microsoft Re-Releases Patches for AMD Bulldozer ArchitectureReported by Theo Valich on Friday, January 13 2012 2:57 amFew weeks back, Microsoft caused a lot of fuss by releasing an incomplete Windows 7 / Server 2008 R2 patch for AMD Bulldozer architecture, which should increase the performance. Download those today.
NEWSSeveral weeks ago,
Microsoft caused quite a confusion by releasing
a patch that was supposed to increase performance of AMD Bulldozer architecture (FX and Opteron 6200 processors) and its Windows 7 and Windows Server 2008 R2 operating systems.
If you recall,
the task scheduler in upcoming Windows 8 operating system properly detects and executes threads on the AMD Bulldozer architecture, while Windows 7 based operating systems do not. However,
Microsoft recalled the patch as the release was incomplete and could have caused system instability.
Just as AMD elaborated, there are
two patches for the architecture, and they need to be installed in the correct order.
If you own a Bulldozer based system, you have to install in this order:
FIRST INSTALL THIS KB2645594The CPU scheduling techniques that are used by Windows 7 and Windows Server 2008 R2 are not optimized for the AMD Bulldozer module architecture. Therefore, multithreaded workloads may not be optimally distributed on computers that have one of these processors installed in a lightly-threaded environment. This may result in decreased system performance for some applications. When this update is installed, the scheduler will be aware that your Bulldozer processor contains dual-core modules. In essence, threads 1-4 now get assigned to their own module first.
THEN INSTALL KB2646060The CPU Power Policies that are used by Windows 7 and Windows Server 2008 R2 are not optimized for the dual core AMD Bulldozer module architecture. This can result in decreased system performance with multithreaded workloads in lightly-threaded environments. When this update is installed, Bulldozer modules will be less likely to achieve the C6 power state. This potentially results in increased power consumption in more lightly-threaded environments.
Let us know in your comments if this patch actually increased the performance of your system or not.
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Microsoft patches Bulldozer’s performance — we investigateBy Joel Hruska on January 12, 2012 at 4:29 pm
When AMD launched Bulldozer back in October, the company claimed that problems with Windows 7 thread scheduler prevented the CPU from
delivering peak performance. According to AMD, Windows 7 didn’t accurately understand how best to schedule threads to take advantage of the company’s shared architecture, and as a result “there are possibilities where opportunities for resource sharing or activate [sic] higher Turbo Core frequencies are missed.”
Microsoft has just released a pair of hotfixes that claim to resolve the issues that handicapped Bulldozer. Curious to see what might have changed, we dusted off our test rig, installed both updates, and ran some of the same tests we’d previously checked.
The updates in question are
KB2646060 and
KB2645594. The first changes how often Bulldozer achieves the C6 power state. MS notes that “this potentially results in increased power consumption in more lightly-threaded environments.” The second update is more vague, mentioning that “multithreaded workloads may not be optimally distributed… in a lightly-threaded environment. This may result in decreased system performance for some applications.”
AMD’s own statements on how much the update improves performance are similarly modest. “Our testing shows that not every application realizes a performance boost. In fact, heavily threaded apps (those designed to use all 8 cores), get little or no uplift from this hotfix – they are already maxing out the processor. In other cases, the uplift averages out to a 1-2 percent uplift.”
writes Adam Kozak, AMD’s product marketing manager.
Here’s what we saw when we installed the updates and started testing. As in our original article, Turbo Core was disabled. A 4M/8C configuration means that a test was run on all four modules with both cores enabled per module. Previously, a 4M/4C configuration was notably faster than 4M/8C in quad-threaded workloads do to scheduling problems.
The good news is that these updates improve Bulldozer’s performance by 2.74% in Cinebench and 3.33% in Maxwell Render. The bad news is just how limited the updates are. As AMD notes, these boosts are limited to “lightly threaded environments” — we saw no performance improvement when we benchmarked these tests with all eight cores enabled.
Hopefully the updated scheduler and AMD’s own admission that it’s of limited use will help put a finish to persistent rumors that reviewers, Intel, and the Illuminati have somehow conspired to make Bulldozer’s performance out to be worse than it actually is. AMD’s demos at
CES 2012 have focused nearly exclusively on the company’s graphics performance, as evidenced by this screenshot of the company’s CES page:
The demos of up-and-running Trinity silicon confirmed reports that the chip is ramping well and that GPU performance is a substantial improvement over Llano, but too many websites have combined two separate statements from AMD. First, that Trinity is based on Bulldozer and has up to four cores, and second, that AMD is targeting a 17W power envelope for its own ultra thin-and-light segment.
The fact that both of these statements are true doesn’t mean that AMD is planning to launch a 17W quad-core based on Piledriver. Even Intel never tried to hit anything near that with a mainstream Sandy Bridge part, opting instead to wait for 22nm and the debut of
Ivy Bridge.
As we head towards AMD’s Financial Analyst Day in February, everything is rosy on the graphics side — at least, apart from the company’s inability to earn
any significant profit from the business — but the CPU side of the equation is full of questions. Bulldozer isn’t getting any magic software-side improvements. Trinity’s GPU is awesomesauce, but the CPU will be doing well to match Llano’s performance-per-watt and 28nm follow-ups to Bobcat remain conspicuous in their absence.
Oct 24 2011, 09:36 PM
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