More AMD Zen Microarchitecture Tuning For Mesa Is Likely Ahead

[phoronix]

Phoronix: More AMD Zen Microarchitecture Tuning For Mesa Is Likely Ahead

Published back in September was some Mesa RadeonSI tuning for AMD Zen CPUs. That tuning to pin the application thread and driver execution thread to the same L3 cache benefits the Zen micro-architecture with its multiple core complexes (CCX). That code was merged a short time later unconditionally but it looks like that behavior needs to be refined for delivering maximum performance...

http://www.phoronix.com/scan.php?page=news_item&px=Mesa-Zen-Needs-More-Tweaking

[shmerl]

The belief is that for applications/games that can make use of many cores, the L3 thread pinning might negate the performance benefit otherwise.

It should be disabled by default then, since normal application is expected to use all cores these days.

[LeJimster]

I must admit I've been conflicted about this one as some titles benefit from the additional cores. With the new chiplet design of Zen 2 this optimization might not be necessary for next gen cpu's, let's hope that is the case.