Just installed the branch prediction patch in my Win 11 VM. I have CCD1 of 7950x passed through and did two quick and dirty benchmarks (I’m not too much of a gamer)
Cinebench R23: 18800ish → 19400ish
Civ 6 gathering storm AI: 28.8 sec/turn → 28.0 sec/turn
So the patch is relevant within a VM as well. Don’t have time right now for elaborate benchmarks (nor the patience ever), but I guess it’s a proof of concept.
Interesting, as I’m getting ready to upgrade my WS to using the same CPU along with some VM’s including Windows 11.
don’t think the patch is available for win11 IOT
at least nothing has come up
You have to get it via the Optional Updates and then the other option is to sign up for the insider preview to get the 24H2 release until it gets rolled out to everybody.
cheers, i thought it was back ported?
Yes it’s backported. That’s the one I installed. KB5041587
Don’t want to mess with preview major updates on Windows… You still need to install this one manually, it is a preview update.
Wonder if this patch is what finally makes me ‘upgrade’ my Windows 10 install to 11. Will have to wait to see if any benchmarks make it worth it for a 5900x.
Nope, win 11 can FOAD. Windows 10 is still in support, they should be applying it there also. But I suspect they won’t for exactly this reason.
I don’t have much experience with W11 and only use W10 for some games at the moment. Have been using EndeavourOS more lately due to not liking the way Windows has been going for a while.
At some point Windows will be moved to the 512GB NVME or SATA for certain things, then move Linux to the two 1TB’s. Another HDD is needed to backup everything that is on the HDD/storage drive before switching that drive away from NTFS.
This is my working assumption. If a backport happens I expect it’ll be quiet like the backport of the Alder Lake scheduler changes was and, similarly, won’t get reported unless someone happens to notice a Win10+Zen perf increase.
At work the official word’s come down to hurry up about Windows 11 migration, so I’ve got a Zen 3, a Zen 4, and a Zen 5 build I’m planning to (re)bench on 10 and then roll forward to 11 to compare. Not a high priority, so maybe data by end September.
Hi @quilt
Did you test core isolation in the VM?
I tried core isolation in the VM for couple of days. It was a disaster under VM. It may half the performance in some applications.
My VM is Win10, with 7950x. Cinebench is not that sensitive in the context of branch prediction. Mostly affected are games, also block io such as virtio disk operations.
inb4 next year’s DEFCON talk, “Patching Hurts, Abusing Branch Prediction for RCE”
After the patch? No… I also had a lot of issues with core isolation/VBS in the VM (before). Have not tried re-enabling it. Some applications were not/barely affected, some lost A LOT of performance, IIRC. It might have to do with how they allocate memory(?) but not sure…