Question regarding Processors

[padre.ayuso]

Hi Ondra and the rest of the team!

Has anyone noticed a performance difference between AMD & Intel processors? I have 4 slaves two of them (the Intel) have 2.67GH and the other two slaves have an AMD with 2.4GH of speed. The rest of the slaves are built exactly the same, with the same RAM, etc. But, the Intel machines seem to render in Corona 10 times faster than the AMD machines, which are rendering literally forever!!!!! I can see it in DR, whereas the AMD machines do 4 passes while the Intel ones do 40 passes in the same amount of time.

I'll keep doing some tests, but I thought it would be good to document this if it has not been yet.

[juang3d]

Can you specify what exactly CPU are those?

Anyways AMD is being historically slower than Intel CPU's

Cheers

[maru]

Anyways AMD is being historically slower than Intel CPU's

Nope. Corona is based on Embree ( https://software.intel.com/en-us/articles/embree-photo-realistic-ray-tracing-kernels ) and it will always work much faster on Intel cpus.
2017 update: Corona works really well on AMDs! Just check out the benchmark results: https://corona-renderer.com/benchmark/

[juang3d]

Yeah, but still AMD is being slower since some years, cheaper also, but slower, if you check all the benchmarks there is no AMD cup in the most top part.
With that said, that does not mean that there are no good AMD cpu's, just saying that we have to know what cpu's they are, and afaik (and I may have understood it wrong) AMD cpu's does support embree also (I think I read Keymaster saying this not so long ago)

Cheers!

[padre.ayuso]

All this makes sense now.

AMD: Opteron Processor 6234 2.4 GHz; 16GB RAM   64 bit system (2 processors)

Intel Xeon CPU  X5650 @ 2.67GHz (2 processors) 12GB RAM; 64 bit RAM

So basically the Intel one is 10 times faster, and I think what was explained earlier makes sense.

[Juraj]

Embree doesn't give more than 30perc advantage at most, AMD simply has weak architecture and had for many years now, the days of Athlon64 are gone sadly.

Opterons are just weak budget cpus, for some tasks (they were popular for mining in past 2 years but even there are better solutions now).

[padre.ayuso]

I have been doing some more renderings and while it differs on the scene, AMD chip was WAY slower than the Intel. This is obviously not a criticism on Corona, but rather when buying a computer and wanting to do CPU renderings, DON'T GET AMD!

Cheers!

[Ondra]

Embree doesn't give more than 30perc advantage at most, AMD simply has weak architecture and had for many years now, the days of Athlon64 are gone sadly.

When first implemented, embree made waaay bigger difference in Corona than 30% - it is líke some crazy unicorn pony magic!

I also tested embree on an AMD rig, and it was not significantly slower. I suspect Corona is slower there because I only develop and optimize on Intel. Maybe sometimes in the future I will try to optimize also on AMD.

[padre.ayuso]

I also tested embree on an AMD rig, and it was not significantly slower. I suspect Corona is slower there because I only develop and optimize on Intel.
[/quote]

Ah! Ondra, that makes sense now. Anyhow, even on Mental Ray, I can see my AMD Slaves to be slower than the Intel ones but it was only with Corona that I could see this to be a full 100% fact.

[Christa Noel]

When first implemented, embree made waaay bigger difference in Corona than 30% - it is líke some crazy unicorn pony magic!

I also tested embree on an AMD rig, and it was not significantly slower. I suspect Corona is slower there because I only develop and optimize on Intel. Maybe sometimes in the future I will try to optimize also on AMD.

yes keymaster, that would be nice if corona is optimized for AMD
i believe that many of corona users are AMD users too. always wait for this development

[Captain Obvious]

When first implemented, embree made waaay bigger difference in Corona than 30% - it is líke some crazy unicorn pony magic!

I also tested embree on an AMD rig, and it was not significantly slower. I suspect Corona is slower there because I only develop and optimize on Intel. Maybe sometimes in the future I will try to optimize also on AMD.

yes keymaster, that would be nice if corona is optimized for AMD
i believe that many of corona users are AMD users too. always wait for this development

The cold hard truth is that AMD are really quite far behind on the CPU performance curve at the moment. There isn't so much that can be done to optimize that away. Ondra's time is much better spent fixing bugs and improving functionality in Corona, rather than putzing around with low-level optimizations that are really the compiler's job. If you care that much about performance, just buy an Intel-based render slave. *shrug*

AMD were ahead back in the Pentium 4 days, but now they're behind. It happens. They might get ahead again, or someone else might get ahead; who knows. But right now, Intel are the CPU performance leaders. By a wide margin.

[padre.ayuso]

Yeah, I guess the thing to do is to dump my two HP slaves that I bought for 2K each and get Intel based... :(
Irregardless, I'm sure Ondra can handle the hard pressing matters first and then tackle the AMD issue. Truth is, MR is also slower in AMD but not to so remarkable as in Corona, where the difference was almost 10 times slower which then may put some people off from using Corona if all they have is AMD chips on their computers, it may, just say, limit the market. If my workstation is AMD based and I try Corona and it is not way faster than VRay I may stay with VRay, rather than buy a new workstation with Intel just to test if Corona works better on the new station. Anyhow, this is not an issue that is important to me, but I thought it may be good for Ondra to know so that he can deal with it as he sees fit.

[Captain Obvious]

10x slower makes it sound like there's some kind of performance bug. I was expecting the top-end AMDs to be more like... I dunno, maybe half the performance of the top-end Intels. Not 1/10th.

[padre.ayuso]

10x slower makes it sound like there's some kind of performance bug. I was expecting the top-end AMDs to be more like... I dunno, maybe half the performance of the top-end Intels. Not 1/10th.

Yeah, well, it also depends on the scene, but the one I was working on was more than half, definitely, and at times it seemed like 1/10th, specially when on the DR window it said that my other two intel slaves were doing 40 passes in the time that my AMD slave was doing 4. So give it a safe margin of 5 or even 6 passes to the AMD and we are still talking a lot of difference. Perhaps it is a performance bug, but all cores were up to 100% on the AMD and everything seemed to be working fine (I checked that all before I concluded the difference on the two machines).

[Christa Noel]

i never do some research / comparation about rendering performance of both kind of CPU. i have 4 PC station, AMD fx6300, i7-4770, i5-4570, i5-4570. i think AMD isnt behind intel CPU, unless we disregards the CPU prices..
CaptainObvious, just like i said before. you should do a research about renderingperformance on CPU. so that, it makes your words more accurate & more valuable to be read. whenever you done this, you may share the result here please..

but thats doesnt even matter whatever anyone said.. i have never get disappointed by AMD's performance.

then... yes keymaster, keep up do your best to improving corona's performance & quality. AMD is the other priority, but dont delete it from your schedule.