On Wed, Apr 25, 2018 at 09:46:32PM +0200, Michael Zapf wrote:
Hi all,
a new observation, maybe crucial to that problem.
I continued my tests on a PC in my second apartment. There I noticed that the bisect location does not apply anymore: This second PC was fast for the formerly bad commit as well. Still, the normal installation from Tumbleweed was still slow.
I rolled back the state of the test installation to try again. There I found:
Once I install ucode-intel 20180312-3.1, the system slows down from 900% to 300% in the benchmark. Rolling back before that ucode package was installed, it gets fast again.
Could this explain why my laptops are not affected, while my three PCs are all hit by this slowdown? It is hard to believe that my 2012 laptop with a Core i5-3320M now visibly outperforms my 2017 PC with a i7-7700K. Let alone that the dually installed Windows 10 on the same PC does not suffer from any slowdown at all (using the Windows build of MAME).
That might be the Spectre V2 fix on new processors, which will slow it down. Can you check output of: cat /sys/devices/system/cpu/vulnerabilities/spectre_v2 Ciao, Marcus -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org