Agner's CPU blog

New CPUs are out for 3-6 months already. There was many blog releases about Zen 5 microarchitecture rework etc, but it didn't come to test here yet.
One of big general improvements is that now Zen features full 512-bit datapath AVX-512 block, gaining additional +40-50% in related workloads, according to Phoronix
https://www.phoronix.com/review/amd-zen-5-core
https://www.phoronix.com/review/amd-zen5-avx-512-9950x
AMD also have released official timings. But as already known from Zen 4 spreadsheet, AMD usually marks variable latency/uops instructions as N/A or ucode without claryfing the exact range, so it much less specific than uops info or Agner Fog's tables in this regard.
https://www.amd.com/system/files/TechDocs/57647.zip

Thank you.
I cannot afford to buy every new microprocessor on the market, just to test it. It would be very helpful if somebody out there can give me access to one of the new microprocessors. All I need is a remote login to a Linux installation on the computer.

Sorry I'm running Windows 11 on a 7800X3D so I can't give you a linux shell but I'd be happy to run any tests for you.

At the moment I'm tesing with A_memcpy() and SetMemcpyCacheLimit() as I've got 96MB of L3 cache to play with.

I'm also interested with the affect of buffer alignment after I found MSVC was calling a memcpy() in a file called D:\a\_work\1\s\src\vctools\crt\vcruntime\src\string\amd64\amd\memcpy_avx_ermsb_aligned_amd.asm

My program does lots of copying of 2MB structs so a few bytes of alignment data doesn't make much difference

spudwa wrote

Sorry I'm running Windows 11 on a 7800X3D so I can't give you a linux shell but I'd be happy to run any tests for you.

If you want, you can boot Ubuntu from a USB stick and run my tests. It will be a great help if you run all my tests scripts and send the results to me.

https://ubuntu.com/tutorials/create-a-u ... on-windows

spudwa wrote: ↑

2025-03-08, 9:09:36

Sorry I'm running Windows 11 on a 7800X3D so I can't give you a linux shell but I'd be happy to run any tests for you.

7800X3D is Zen 4, not Zen 5.

Would WSL be okay?

Sorry about the Zenni 4/5 mistake. Didn't realize I'm obsolete already!

spudwa wrote:

Would WSL be okay?

I am not sure if the driver works under WSL.
I already have test results for Zen4