Thursday, August 22nd 2024
AMD Works with Microsoft to Improve Zen 3 thru Zen 5 Performance in Windows 11 24H2
AMD Ryzen 9000 "Granite Ridge" desktop processors have been out for a couple of weeks now, and the "Zen 5" based processors have fallen short of gaming performance expectations, set mainly by some of the numbers AMD put out in its Computex 2024 reveal for the processors. The consensus among the tech press is that these processors are roughly 3-5% faster than Ryzen 7000 series "Raphael," but with noteworthy improvements in energy efficiency. AMD set out to study why there are such vast deltas in performance between its numbers and those of reviews, and arrived a few possible explanations. The company also stated that it is working with Microsoft to fix this in the next major update to Windows 11.
One of them is that AMD's testing was done on Windows 11 23H2 with Admin mode (i.e. a local system administrator account was used), while some reviewers tested with a regular user account that has some admin privileges. Apparently this affects the way the branch prediction units of "Zen 5" processors work. "Our automated test methodology was run in "Admin" mode which produced results that reflect branch prediction code optimizations not present in the version of Windows reviewers used to test Ryzen 9000 Series," AMD said in a statement.
AMD also pointed out that in its first-party tests that compare Ryzen 9000 series processor models to Intel's, the company ran the 14th Gen Core chips with the same DDR5-6000 memory speed with the same timings, and used Intel's baseline power profile that uses stock power limits for these processors (125 W base- and 252 W maximum turbo power in case of the Core i9-14900K and the i7-14700K, for example).
AMD said that it's working with Microsoft to bring the "correct" branch prediction behavior seen in admin mode to regular Windows 11 user accounts. These updates will be incorporated in the retail release of Windows 24H2, although you won't have to wait until then. Microsoft will release this as an "optional update" sooner than that, so it could be implemented on Windows 11 23H2. Here's the best part—it turns out that the admin mode discrepancy even affects "Zen 4" and "Zen 3" processors, which means even Ryzen 5000 thru Ryzen 7000 series processors should get a performance uplift in regular Windows 11 user accounts.
Source:
AMD
One of them is that AMD's testing was done on Windows 11 23H2 with Admin mode (i.e. a local system administrator account was used), while some reviewers tested with a regular user account that has some admin privileges. Apparently this affects the way the branch prediction units of "Zen 5" processors work. "Our automated test methodology was run in "Admin" mode which produced results that reflect branch prediction code optimizations not present in the version of Windows reviewers used to test Ryzen 9000 Series," AMD said in a statement.
AMD said that it's working with Microsoft to bring the "correct" branch prediction behavior seen in admin mode to regular Windows 11 user accounts. These updates will be incorporated in the retail release of Windows 24H2, although you won't have to wait until then. Microsoft will release this as an "optional update" sooner than that, so it could be implemented on Windows 11 23H2. Here's the best part—it turns out that the admin mode discrepancy even affects "Zen 4" and "Zen 3" processors, which means even Ryzen 5000 thru Ryzen 7000 series processors should get a performance uplift in regular Windows 11 user accounts.
83 Comments on AMD Works with Microsoft to Improve Zen 3 thru Zen 5 Performance in Windows 11 24H2
instead of improving and adding on it's breaking and repairing what was fine and working
Watched this video in morning and FC6 and CP2077 are outliers it seems.
Then again, I wonder if WIn10LTSCEntIoT even has such issues that need addressing?
average person can use this without any issues.
-if older was already better, there wouldn't be any need for a new fix/update/component. (which, wouldn't be the first time such has happened.)
Though I guess the true answer is probably behind at minimum a couple NDAs and a graduate-level course in modern processor architecture.
At least by the L1T/Wendell vid, I got the jist that the issue revolves around 'virtualized security'. Is this even an issue at all for those not running VBS, Linux in Win10, HyperV, etc.?
Knowing the optimizations in the past few years specifically for MPO and flip model, there's no way I would go back to anything earlier than 23H2, let alone Win10 for that matter. Even if it was LTSC.
But then again, Win10 never really had performance problems with bigger Zen 3 CPUs whereas Win11 has. So maybe for Zen 3 I'd just stick with Win10.
I find it baffling that large thing like this (performance degradation with common Windows setup) is missed in testing the product before release.
They do test the product before release, right?
Maybe if running the games/apps with "Run as administrator" will work the same as running them with the Administrator user?
I see that lately we have to update the BIOS each month and do a lot of tweaks in BIOS to get "stock" performance and stability (on Intel and AMD now) + OS tweaks! :)
Win 11 Bare metal >= Future patch
Probably
Not holding my breath for large gains to be had from admin/scheduling fixes, but it's welcome that they're committed to trying to get people the touted performance.