AMD Vishera Multi-Core Scaling Performance

[phoronix]

Phoronix: AMD Vishera Multi-Core Scaling Performance

For some additional benchmarks to share this weekend, here are some multi-core scaling numbers from the AMD FX-8350 Vishera that launched a few days ago.

http://www.phoronix.com/vr.php?view=18080

[jannis]

Impressive results. Would've been nice to have those "normalized" to a "per core" value so one can directly see the overhead

[renkin]

Michael, Can you show the settings used for libvpx encoding?

[bug77]

I wonder whether all these are testing the scalability of the CPU or the software...

[bobwya]

I wonder whether all these are testing the scalability of the CPU or the software...

Gotta say that a normalised per-core comparision with the Ivy Bridge 3770K (or similar) would have been nice...

[PeterKraus]

Also, power consumption?

[jason]

Impressive results. Would've been nice to have those "normalized" to a "per core" value so one can directly see the overhead

As I read I did go through with a calculator and do just that without saving the results. Basically the results seemed to be 95-105% (estimated without a percentage calculation) scaling to using more cores. I started calculating at the compile times, but after the reading the forum I took a look at libvpx and it looks to be a very serial task were each addition core dropped per core performance badly. Showing seconds and fps are terrible for per core efficiently. I don't fps at all, time per frame is better.

[schmidtbag]

I'd say this CPU scales quite nicely, a hell of a lot better than i7 when turning off HT. Id say AMD did a pretty good job with their module idea, i just think they should've stuck with a longer pipeline rather than higher clock speed. However, even though going from 6 to 8 cores does seem to scale properly in most of the tests, the overall performance addition you get doesn't quite seem worth it, although I'm not sure how much the FX61xx series will cost. The dumb part is the phenom II x6 is likely going to be still faster than the FX hex cores.

[mayankleoboy1]

I'd say this CPU scales quite nicely, a hell of a lot better than i7 when turning off HT. Id say AMD did a pretty good job with their module idea, i just think they should've stuck with a longer pipeline rather than higher clock speed. However, even though going from 6 to 8 cores does seem to scale properly in most of the tests, the overall performance addition you get doesn't quite seem worth it, although I'm not sure how much the FX61xx series will cost. The dumb part is the phenom II x6 is likely going to be still faster than the FX hex cores.

longer pipelines with slower clocks will make a poor performing CPU. If there is a branch prediction mismatch, the entire pipeline has to be flushed and filled with new data. AFAIK, longer pipelines go hand in hand with faster clocks.
What AMD can definitely do to improve performance, is to improve their branch prediction algos. But that is already a diminishing result problem. The predictions algos are already highly fine tuned. And any more fine tuning is workload dependent.

[smitty3268]

AFAIK, longer pipelines go hand in hand with faster clocks.

This is correct. Longer pipelines exist to increase clock speed, with the downside of doing less work per-clock.