Blackmagic Forum

Possibly a Dwaine question, but I'm open to anyone who has the right answer! I've had quite a few odd questions of late.

Without doing extensive trial-and-error experimentation, I'm trying to determine how best to reconfigure my cheesegrater mac pro to improve render times.

I have an older GPX expansion chassis. I was running two 680s - one in the mac and one in the expansion chassis. Then, I replaced the one in the expansion chassis with a Titan XP. However, although I could now render 4k frames without stalling or crashing, the overall render time for HD did not improve significantly. I flipped the switch so the 680 is gui only, and is not being used for render.

Finally, I was able to get two 1080ti cards at a fair price - so I've just pulled the titan and put two 1080ti into the expansion chassis. The Mac and resolve see them just fine. I've left the 680 in as the GUI.

Weirdly, though, I'm not getting significant better render times - not much better than the dual 680, actually. I figured NR in particular would improve dramatically, but it's really not.

(Source is mostly DNG from a pair of very fast local SAS raids.)

Could the 680 be slowing down the 1080ti, even though it's GUI only? Also, I read the 1080ti is power hungry - so I'm reluctant to move one into the mac itself.

Anyone us this specific or similar configuration? Just wondering if there's something obvious I'm missing or choosing to ignore.

I'm putting enough money into graphics cards that starting to wonder if I'm tossing good money after bad and perhaps should consider building a PC (or hackintosh,) but I need ProRes, and I've been on Macs for some time now. (Also, need to stop spending money on this problem!)

Thanks in advance for any tips.

Well, first of all, you didn't waste your money. Those cards will serve you well with a newer Mac or a PC too.

Now, which "cheese grater" do you have? It should be a 4,1 or a 5,1, anything less won't cut it anyway. Plus, those machines are somewhat limited in other areas too. Resolve needs a very balanced system, which CPU do you have? If it's not a dual CPU, I wouldn't even bother to use that machine any more. If it is, get the newest and fastest one you can afford and have the firmware upgraded, so that it becomes a 5,1 (if it was a 4,1).

The 680 might throttle down your system too, take it off and see if one 1080ti can run in the main box. Finally, you may not see as much of an improvement with the second one in the expansion as you expect, the whole data throughput in those machines is a bit outdated. We got a pretty balanced system with one Titan-X in an old MP with a 12-core CPU, but that was about it.

Huh... so a newer system may well be in the offing... ahrg.

This system is a 12-core 5,1 but with 2.66 processors, rather than 3.33 or 3.46. Everything else is kind of as tweaked out as it can be.

The machine works fine-ish, but I really expected improvement from the new GPUs, and they're not making much of a difference. Certainly not $1400 worth.

Yes, sorry for that. Either put the 1080ti into the machine, drop the 680 and enjoy (the power supply should suffice) and sell the rest.

Or get a PC or Hackintosh with newer hardware.

Or go for maxed out iMac (non Pro) with 8 GB VRAM and a TB3 expansion chassis with one 1080ti. Maybe even two, but I can't promise it'll do much. But that machine is going to surprise you.

When we maxed out our cheesegrater in late 2016, it made a lot of sense. With the 2017 iMacs, not that much any more. Let's just hope Apple finally delivers a reasonably expendable new MacPro (instead of that overpriced iMac Pro), or we may leave them behind. I say that as a die-hard Apple fan, who switched from PC to Mac around 2002 and never looked back – until now!

Putting one of the 1080ti in directly in the Mac seems to be working fine. true test will be render, but it does seem to to work better. NR doesn't even flinch now.

Unfortunately, I'm using a lot of Boris BCC OFX plug-ins which, I recently learned in another thread, are processor dependent and single-core. Uhg.

I made what I hoped would be a 'stress test' rendering a full show to a codec different than my cache codec, and any of the shots will BCC render 3-5 fps, which is what I was getting before spending money on new graphics cards. The shots with blur and NR, or just a half-dozen grading nodes, render 40-60 fps, so about 50% faster than before, so there's that. And no crashing for power, at least not yet.

I'll try rendering at 4k later today and see what kind of speeds I get. (with dual 680s the system was 2-5 fps or just stalled completely.)


gh

Well, if something is completely CPU based and even single core, you can't do much about it.
Maybe try to find better tools, which are optimised for GPU ?

Greg Huson wrote:Putting one of the 1080ti in directly in the Mac seems to be working fine. True test will be render, but it does seem to to work better. NR doesn't even flinch now. Unfortunately, I'm using a lot of Boris BCC OFX plug-ins which, I recently learned in another thread, are processor dependent and single-core. Uhg.

Greg, we try to manage this problem by creating a 5.1 render station that only does renders, and that at least frees up the main system for paid clients. The problem in your case would be having to pay for a second set of BorisFX plug-ins -- but they can and will give you a reduced price on multiple licenses.