I couldn't detect which packages are responsible for it, but Shadow of The Tomb Raider (Vulkan) has suffered 16% perform drop after glibc massive update (between January and February) in current. It seems like a CPU bottleneck, according to the benchmark.

I have GTX 1650 Super, and both kernel and Nvidia drivers (460.56) are still the same.

Funny enough, OpenGL performance hasn't changed at all.

I don't know much about this topic I admit. Did you try reinstalling the nvidia drivers? The way I understand it, they are kernel modules that should be rebuilt from time to time.

I tried it, but it didn't change anything.

This is very odd. I actually got an 11% improvement with the 460.56 driver (GTX 1070 Ti - 99% GPU bound) compared to the same test a month ago with the 460.39 driver. The only additional system differences from a month ago are all the slackpkg+ updates (as of last night) and a custom low-latency 5.10.22 kernel. Odd.

Perhaps it is as you noted a CPU bottleneck in your system since in my system the CPU far outstrips my GPU. I want a 3080 but who knows when that can happen . My CPU is an i5-10600K mildly clocked to 5.0 GHz all cores. That still doesn't explain why my scores went up.

For Intel processors turning on all in-kernel security features can be devastating, some have reported up to 40% drop in performance. It has nothing to do with Linux of course and has everything to do with Intel hardware bugs. If you do not build your own kernels and had a kernel upgrade lately then the reason is likely right there.

That makes sense, Emerson, as I commonly use "make oldconfig" or "make olddefconfig" which would defeat new defaults.

The thing is: the kernel and the drivers haven't changed!

Anyway, when building kernel I just need to call 'make oldconfig' to not apply security features? I have an old and simple Pentium G4560 (2 cores + 2 threads), so any performance improvement is welcome

'make olddefconfig' is the worst you can do to your custom kernel, it will apply the new defaults without asking you.

shrug:
just run diff to see what is new the leave it or remove new option.

Found it how to disable kernel mitigations: https://linuxreviews.org/HOWTO_make_..._on_Intel_CPUs

And here some benchmarks: https://www.phoronix.com/scan.php?pa...ltdown-2&num=2

1 members found this post helpful.

You run 'make oldconfig' and it will ask you. If you like the easy way, that is.

fulalas,

thank you! I had all these options carefully disabled in my kernel, your research and findings make life easier. I need max CPU performance for video processing in my desktop and I'll leave those mitigations for my servers.

I don't find this likely, but is there any chance at all that your CPU frequency scaling settings might have changed?

@dugan, it's set to 'performance' since forever -- I've just double checked it.

I'm about to find out what is causing the performance drop. It's something inside /lib64 (not /usr/lib64). I need more time to test it and then I'll let you guys know.

either or
So is oldconfig asking or applying new defaults without asking?