Power supply and 2 cards

[treddie]

Well...I was hoping to buy a 570 with 2Gb of memory at a decent price, but looks like I'll have to back down to a 560 w/ 2Gb.

My main concern now is, I am running an EX58 Motherboard with a GTX 260, a couple of hard drives and 12Gb RAM, all powered by a 750W Pwr supply. My UPS is showing a peak load of about 360W while the single GTX260 renders a huge Octane scene, and Maxwell renders a scene of its own using all 8 CPU threads. Does anyone have any advice on whether or not the 750W PS will be ample enough to handle the addition of the GTX560 alongside the old GTX260, and whether or not the 3 fans I have going now will suffice? The specs say that the GTX560 pulls a max of about 150W, so If I assume my peak load now of about 360 +150, I'll be seeing ballpark 510W when my system is pretty much running full bore. Throw in another 100W of hypothetical overload and that puts me at maybe 610W. SOUNDS like it should handle it, except for the pwr supply running a lot warmer AND that with the space between both cards being probably 1/8" at best, I imagine it could get pretty toasty in there (The GTX260 already runs too hot to touch by hand when its rendering).

[glimpse]

By numbers it should be enough, but it's hard to say for sure. In the end everything depends on efficiency and quality of your PSU. In these times some PSUs perform better some worse than the numbering on the box..quality is important, thats why price ranges differs so much. But by numbers, as said before it is enough.

About the temperature. You can always underclock your card a bit - yes You are going to loose some speed, but maybe at least your mind will be a bit more calm =)

[PolderAnimation]

Hi, my system is a 460 gtx + 580 GTX 12 gb RAM, 1 TB harddisk and a i7 2600.
I run this with a 650 watt power supply.
When I only run octane on 2 cards (without rendering on my cpu) I use 360 watt.
So I don't think I will go over the 650 watt if I render with my i7 2600.

I also tried a 570 gtx allong side my 580 gtx to render, but then I saw a peak of 650 watt when octane started and a second later it was stable on 380 watt. It never crashed but I put my old 460 gtx back, just in case.

This is all the info I have, I think 750W will do, specially because a 560gtx isn't a very power consuming card.

[treddie]

Thanks, glimpse.
SpeedFan says the 260 is running at around 84C (its published max is 105C). The 560 spec says 99C max. So I guess I'll just keep a sharp eye on the temps when I test it out.

PolderAnimation > That's encouraging. Are your two cards sitting right next to each other like mine will be?

[PolderAnimation]

My cards are very close together, I have 2 case fans (92mm I believe) running on medium speed.
It is enough for rendering on both cards. Dunno if it will be enough with a cpu running next to it.

[treddie]

Well, at least the CPU is up above with a decent 2" clearance, in my box. I'm feeling good about this overall.

[treddie]

Man, this 560 is killer. And its just a 560! My rendering time is about half what it was with the little 260. And I can load large models now. Temperature is decent at 80C for the 560 (Ambient temp is 25C-26C).
Power spikes at no higher than about 404W on my 750W Pwr Sply, while also tying up all of my CPU cores running a Maxwell job. Big thanks to Refractive for building Octane and making this possible! This GPU thing is like having a huge render farm inside my case.

I can't imagine what a Quadro or Tesla would do.

[treddie]

I have to revise my time improvement. It's way better than 2x...the old render on the 260 was at 2000x1000, and the new one on the 560 is 3000x1500 with a bitmap texture at roughly 4x resolution of the old. It's practically impossible to measure performance by looking at noise on the screen, and I forgot to log the stats on the left, but it's way better than twice the quality of the old render in the same time period, subjectively speaking.

[steveps3]

I went from a single 260 to 3 x 560ti cards. The difference nearly blew my hair off.

[treddie]

I wish I were in your shoes! But even my one 560 blows me away. I got up this morning to check a 4000x2000 test render I started last night and after 9 hours, it was probably about where a non-GPU-based MLT would have been at, at 30 DAYS. So using your setup, it would probably be noise free, or close to it by now.