Question IPC revision for Raptor Lake / Zen4 in light of Spectre V2

[igor_kavinski]

I suppose there will be a minimum of 5% impact on Raptor Lake and Zen 4 IPC due to Spectre V2 (BHI) mitigation patches in most workloads. Alder Lake will be screwed shortly by a Windows update mitigating BHI. What else? Can Zen 5 and Meteor Lake/Arrow Lake be modified at this point to avoid this performance regression?

 

[Mopetar]

It's at times like this I wonder how I got to be a mediocre Excel monkey instead of having my dream job of testing the latest and greatest hardware for the performance impact of just-landed-security-vulnerability-mitigations. Oh wait, I know. Coz most offices don't give a damn about how slow their hardware is gonna get by some mitigation patch but they do care about having an Excel monkey around to do their dirty work. *sigh*

Why should they care if Facebook runs slower than it used to?

 

[Hougy]

Things are not looking good for future PC ports of PS5/Xbox Series X games on Alder Lake that will depend on the DirectStorage API. 5800X3D is looking pretty attractive in this context.

Why won't DirectStorage work with Alder Lake, do you have a link? Will it work with Raptor Lake?

 

[igor_kavinski]

Why won't DirectStorage work with Alder Lake, do you have a link? Will it work with Raptor Lake?

I'm not saying it won't work. If and when Windows gets patched for the BHI security flaw, NVMe SSD I/O performance may drop. Nothing is certain for now. We have to wait for the patch to be released and SSD performance impact needs to be measured to get the full picture.

AMD CPUs have a better chance of avoiding such a performance degrade, if it indeed happens due to the Windows BHI mitigation patch.

 

[TheELF]

I'm not saying it won't work. If and when Windows gets patched for the BHI security flaw, NVMe SSD I/O performance may drop. Nothing is certain for now. We have to wait for the patch to be released and SSD performance impact needs to be measured to get the full picture.

AMD CPUs have a better chance of avoiding such a performance degrade, if it indeed happens due to the Windows BHI mitigation patch.

The whole idea of direct API is to get a data STREAM going as fast as possible, it's not going to be tons of small files going back and forth it's going to be big batches of data being pushed one way so the mitigations should have little to no effect on that.