[el.mustafa]

Hi everyone.

I don't know how Maxwell scales with multi-core processors.

For example:

There are a few Cinebench tests comparing Intel Xeons and AMD Opterons.
Would the tests of a scanline renderer such as Cinebench be useful to someone
using Maxwell render?

I'm interested because I encountered two render node solutions offered by the same company.

One with 96 Cores AMD 2.1GHZ (8 X 12-cores) which is considerably less expensive than
48 Cores Xeon 5645 (8 x 6-cores) running at 3.33 GHz.

What suits Maxwell best?
Faster processors or multiple cores?

El

[Half Life]

Faster processors definitely... I saw a test with 48 cores that suggests that efficiency per core drops as you get higher in core count -- not by much but by the time you get to 48 cores it looks like you lose about 20% efficiency per core over a standard 6 core solution. Which makes sense with all the extra overhead of managing that many data pipes.

Obviously there are advantages to having all those cores in one system -- but I would take the option with the fastest processors.

My understanding is this efficiency issue may level out at higher sample levels (20+), but not many seem to be willing to let their scenes mature to those levels to find out.

Best,
Jason.

[el.mustafa]

Thank you Jason.


The units are split into 4 render nodes so hopefully the
drop in performance will not be as bad as 20% on the 48 cores
as long as renders are in non-cooperative mode.

El

[Half Life]

Yes, that would be true based on what I understand -- and of course this may be less of an issue when dealing with high sample level scenes anyway

Best,
Jason.

[Bubbaloo]

Cooperative mode will have little if any impact on performance, until it merges the mxi's.

Get the 8 x 6-cores. I'm not 100% sure, but I'm willing to bet that the Intel 6-core will outperform the AMD 12 core head to head with Maxwell.

[brodie_geers]

What you guys haven't talked about yet, though, is the fact that the AMD setup has a total of 201.6 Ghz (96 cores x 2.1 Ghz/core) vs. the intel setup of 159.84 Ghz (48 cores x 3.33 Ghz/core) which is 26% more. From everything I've seen Maxwell acts pretty linearly, but I've never gotten into this many cores (if you have the time and inclination perhaps you could email a couple render farms for advice?), so even if there was a 20% hit which seems to be on the high end, the AMD would still be a bit faster (and quite a bit cheaper as was mentioned).

I do believe HT has been shown to increase speed, though. The xeons have HT, what about the AMDs?

-Brodie

[Half Life]

What I should have said to make it clear is: " the more cores the more you will notice a loss" because the tested system was only 48 cores the results only showed up to that point but it very clearly showed a loss as you added more cores.

What I'm saying is I don't believe it "tops out" at 20% loss -- I think the more cores the more you lose in efficiency... so the larger core count may be moot (unless as I said the jobs are divided in more sensible divisions of core-count)

Nearly linearly is not the same thing as linearly -- and obviously this is a very extreme core count not available to most users at this time... I imagine Maxwell will adapt when those core counts are considered more "normal".

Best,
Jason.

[numerobis]

What you guys haven't talked about yet, though, is the fact that the AMD setup has a total of 201.6 Ghz (96 cores x 2.1 Ghz/core) vs. the intel setup of 159.84 Ghz (48 cores x 3.33 Ghz/core) which is 26% more. From everything I've seen Maxwell acts pretty linearly, but I've never gotten into this many cores (if you have the time and inclination perhaps you could email a couple render farms for advice?), so even if there was a 20% hit which seems to be on the high end, the AMD would still be a bit faster (and quite a bit cheaper as was mentioned).

I do believe HT has been shown to increase speed, though. The xeons have HT, what about the AMDs?

-Brodie

no, AMD has no HT - a 12 core opteron can be compared with a 6 core xeon with ht
here are some cinebench scores:

http://www.anandtech.com/show/2978/amd- ... ore-xeon/6

in this comparison they used two Opteron 6174,12x 2.20GHz (~1000€ inkl. VAT) and two Xeon 5670, 6x2,93GHz (~1150€)


so the 2.10GHz Opteron 6172 (~850€) mentioned in this thread should be a bit slower and the xeon 5680 with 3,33GHz (~1350€) should be a bit faster. so the difference between these two systems should be more noticable.
A Xeon 5645 is only 2,4GHz (~450€) not 3,33GHz! so this one maybe could be at the same speed like the 2,1GHz opterons...

As far as i remember maxwell scales a bit better with HT-cores than cinebench - but i have no scores to prove it...

a new benchwell site would be helpful!!!! Where is the problem with it that it take 2 years to set up a new one?!?