Advice needed to build a GPU rendering workstation

[cadman5]

Hi All:

I am thinking of building a GPU rendering workstation and I'd be grateful if I can get answers to some of my questions.

1. How many GTX 1080 can I put on a single workstation without affecting its stability due to heating or other issues?

2. What motherboard can you recommend that could fit 4 GTX1080 ?

3. How powerful needs to be the PSU to handle comfortable these 4 cards plus the rest of the system? (going for an i7 processor, not Xeon)

4. Are there any advantage / disadvantage of having these 4 cards externally connected through a GPU expander? If the expander option is better, is there a ready made solution that you could recommend?

5. How long these cards can normally last if used daily for rendering? (no overclocking). Will they underperform or easily broke with time?

6. Is there a Vray licence limitation on how many GPU cards can be used on a single system? What about licence limitations if using a GPU expander?

7. Will rendering with 4 GTX1080 be faster than say using a dual "14 core Xeon E5-2690 v4" processor? (I hope so, but would like to know for sure)


Any help will be appreciated.

[Raph4]

Hi cadman5.

1. If you want add one or more GTX1080 best is using watercooling.
I use one waterblock / GPU , picture of my setting here :
http://forums.chaosgroup.com/showthr...ition-vs-Other

it's not 4x 1080, but one 1080 + 2x 980Ti + K5200 inside large tower (Thermaltake Core X71).
The 1080 sends a lot of heat even at idle.

I don't recommand using more than one 1080 without waterblock.
I divide heat by two with waterblock and can control ALL FAN speed with one rheobus (Thermaltake Commander F6 RGB).

6. No limitation for GPU with vray licence.

[cadman5]

Thanks Raph4!

How powerful is the PSU inside your Thermaltake tower?

[Raph4]

I have added one 1200W PSU.
model: Corsair AX1200i

[gregvfx]

I am also looking for making a 4 GPUs workstation, I haven't built a computer for more than 15 years and I wonder if the number of PCIe lanes is making a difference?
Or is it for gaming only?

Also any news of a consumer version of NVLink? like how many years before we can see it in ASUS or GIGABYTE MOBO?

[savage309]

Pretty much this should answer 1, 2 and 3. 4 - there are expanders.

PCIe speed should not have major impact on the render speed, but I can't recommend any expander yet.

5 - AFAIK, they should work just fine.
6 - No limitation. 7 - It should, but as usual, it is always better to test first .

Considering it still has to hit the HPC market, I think it might be a safe bet that NVILINK will take a while longer until it becomes massively adopted.

Best,
Blago.

[eyepiz]

I built this setup years ago with the original Titans when they came out, all air with stock coolers and a 1500W PSU, it ran for days at a time at full blast on the (4) cards. the 1080's draw even less power.

The only disadvantage was that the GPU driving the displays was disabled most of the time for RT GPU while working, the UI lag was pretty bad.

[biochemical_animations]

I built this setup years ago with the original Titans when they came out, all air with stock coolers and a 1500W PSU, it ran for days at a time at full blast on the (4) cards. the 1080's draw even less power.

The only disadvantage was that the GPU driving the displays was disabled most of the time for RT GPU while working, the UI lag was pretty bad.

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Do you recall what the temps were on the gpus? I'm planning to build a 4 gpu rig next year and want to stay with air, but am concerned about the lack of gap between each card and how that might affect air flow cooling.

[eyepiz]

I don't recall what the max temps were, but they were within the operating range specifications and they don't run cool. I used a more aggressive fan curve when running them for days on end with animations. I had the super clocked Evga versions and they did not throttle, the Nvidia reference blower style cooler looks to be built to handle a 4-way card setup. I used them for about 3 years and not a single card died..maybe I was just lucky.

I did go through 4 PSU's before I could find one the could handle the massive amount of power the system was pulling off the wall.