Multi Procesors (Xeons)

[Paul_Selhi]

Not sure if I have asked this before but how well does TFD work on a multi CPU rig ? Dual/Quad processors etc ?

[Jascha_Wetzel]

Multi-CPU machines are no different to TFD than a single CPU with a high core count. If you want to dig into the details, TFD runs in SMP mode rather than NUMA mode. As a result, what i wrote below about Threadripper performance also applies to Multi-CPU machines.

Threadripper performance

Yes, TFD will happily use as many cores as you can throw at it. The shot below is from a 3960X. Note that GPUs like the 1080, 2080 and comparable will still be much faster, though. This is because of the 5-10x higher throughput GPU memory has compared to any CPU. Also, the 64-core Threadripper 3990X is unlikely to be of much of value to TFD because it has to feed its cores through the same 4 memory channels as the 24 and 32 core versions do (for comparison, Epyc CPUs have 8 memory channels). Da…

[Paul_Selhi]

I don’t know if you recall and old web tutorial on building a dual xeon box and how cost effective it was buying up old xeons. Not that i have a penny to spare but hopefully things will turn around and I was thinking instead of a Threadripper maybe dual xeons, perhaps even second hand ex servers ? But then again you need double the RAM and A high end power supply etc etc. Still as a cheap render farm ? I really need another box as my PC gets tied up with sim and render tests, just did a 7 hour sim and am now rendering out…still I can waffle on forums. This test was to see if high level sims and high render settings are really worth it considering a lot of the final sim is masked by secondaries, camera cuts and other scene elements. I am at 5 mins a frame 2560x 1440 ( that is so i get youtube to compress to vp09 instead of that crappy avc1, yes I know I should use vimeo but YT gets the exposure !! YT will change the vid to vp09 once they get enough views) for a 240 frame animation on my old 3930K 6 core…still a good workhorse. I will try it on Redshift demo next . I love redshift for scene rendering but still not as keen on it for TFD as advanced render. For those unaware youtube recompresses all video to a really noisy format avc1 and that is very annoying when you have a high detail video, to get it to default to the cleaner vp09 I have found the trick is to upload at this high resolution but rarely do it !! One of my customers does render out redshift renders for me if i ask nicely but only for reasonable sized caches…this one is asking a bit much at 125 GB !!

[Jascha_Wetzel]

I don’t know how the cost/performance ratio changes for used hardware. For new parts that ratio is considerably worse for Xeons than for the current Threadrippers.

One advantage that Xeon and Epyc have over Threadripper are the higher memory channel counts. Typical Xeon/Epyc CPUs have 8 while Threadripper has 4. That translates to roughly twice the memory throughput (except that mem clocks are somewhat lower on Xeon/Epyc). This can be beneficial for voxel and particle sim and renders.