Anomalous Extended Instructions Score – Ryzen 7 8840HS

[Mark35]

Hi,

I recently saw PerformanceTest on a Ryzen 7 8840HS system and noticed a major discrepancy in the Extended Instructions score resulting in a score of 5105 instead of the usual 25000:

• Extended Instructions: 551 Million Matrices/Sec
• Expected Average: ~20,748 Million Matrices/Sec
• Baseline ID: 510344758499
• Other scores: All other metrics (Integer Math, Floating Point, Physics, etc.) are within expected range or slightly above average.
• PassMark Software - Display Baseline ID# 5103447

[David (PassMark)]

For that baseline, the tests were done on on a rare operating system, CachyOS. And this isn't one the OSs that we officially support. In fact we've never even heard of it. I would not be surprised if that was the cause.

For the Extended Instructions test there is an initial step to identify the available instruction sets. These include SSE, FMA, AVX, AVX512 & NEON. (We are also working on adding AMX in a future release). Maybe this detection step fails on this OS and the code path falls back to the un-accelerated C++ path. This would explain this poor result on this machine. This also also why running benchmarks is important for the user to detect and fix stuff like this.

[Mark35]

Interesting,
I noticed however that the same OS and likely same PC scored 24797 in a previous test with SSE score

16,794 Million Matrices/Sec

Baseline ID# 5103444

[David (PassMark)]

Hard to be sure of the cause without access to the machine and / or collecting some debug logs.
Could just be something simple, like some background task running at the same time the Extended Instructions test was running.