1080ti power draw under load? Workstation question

[OddsCrazyStuff]

Quote

https://www.facebook.com/groups/OctaneRender/permalink/835546873289059/

11x GTX 1080ti (no OC),
dual Xeon v4 (max ECC RAM 1024GB),
max power draw 2150W on dual titanium 1600W PSU

 

If 11x 1080Ti + dual Xeon draws 2150W, does that mean 7x 1080Ti (what can fit on an EATX motherboard) with X99/X299/X399, will draw less then 2000W?

 

I got the crazy Superflower 2000W 8Pack PSU (http://www.super-flower.com.tw/products_detail.php?class=2&sn=16&ID=119&lang=), but I'm not sure even it can handle that type of rig.

 

Was planning 4, but found this (7x 980Ti on 1600W)(http://tomglimps.com/7_gpu_workstation-1000_octanebench/). Which suggest I might be able to get more GPU power for 3D rendering and such.

[Enderman]

Yeah it will definitely be less than 2kW.

[reapzzer]

Just make sure to cool it somehow. You don't want to melt inside or throttle like crazy

[OddsCrazyStuff]

Just now, reapzzer said:

Just make sure to cool it somehow. You don't want to melt inside or throttle like crazy

480mm + 2x360mm radiators, so dont think cooling is an issue.

Even if the surface is too little, so should this model handle the heat (will just be a bit noisy at load): http://hardwarelabs.com/nemesis/gtr/gtr-480/

 

5 minutes ago, Enderman said:

Yeah it will definitely be less than 2kW.

Guess the question then is, would it draw more on startup?

[Enderman]

6 minutes ago, OddsCrazyStuff said:

480mm + 2x360mm radiators, so dont think cooling is an issue.

Even if the surface is too little, so should this model handle the heat (will just be a bit noisy at load): http://hardwarelabs.com/nemesis/gtr/gtr-480/

 

Guess the question then is, would it draw more on startup?

Nah, will be ok.

[OddsCrazyStuff]

This has me confused:

 

7x AMD R9 Nano with dual Xeon draws a little over 1500W, while 11x Nvidia 1080Ti with dual Xeon draws 2150W. Based on the 2 sources.

The TDP for the GPU setups is 1225W for R9 Nano and 2750W for 1080Ti, yet only the R9 Nano system makes sense with normal powerdraw math.

 

Ether so does the 1080Ti draw less then the rated 250W or so does Octane Render not use 100% of the all the GPUs.

Knowing which one it is, lets me know if I can put 7x 1080Ti on a single PSU or if I need to mod the case for a 2nd PSU.

[STRMfrmXMN]

I would not power 7 1080 Tis on a 2000W PSU. If we estimate (safely) that each card uses 300W (279 according to this, but I'm being safe here - you're powering thousands and thousands worth of hardware) then you're hitting 2100W for *just* the GPUs.

[Marinatall_Ironside]

3 hours ago, OddsCrazyStuff said:

 

If 11x 1080Ti + dual Xeon draws 2150W, does that mean 7x 1080Ti (what can fit on an EATX motherboard) with X99/X299/X399, will draw less then 2000W?

 

I got the crazy Superflower 2000W 8Pack PSU (http://www.super-flower.com.tw/products_detail.php?class=2&sn=16&ID=119&lang=), but I'm not sure even it can handle that type of rig.

 

Was planning 4, but found this (7x 980Ti on 1600W)(http://tomglimps.com/7_gpu_workstation-1000_octanebench/). Which suggest I might be able to get more GPU power for 3D rendering and such.

To answer your question, yes 7 GTX 1080 Ti's with X99 will pull less than 2 kW, but you also have to consider storage (SSD/HDD RAID), RAM (number of sticks), and the board it'll sit on (boards with PLX switches or dual CPU sockets will need a maximum of 150 watts to properly operate) so the total system power draw with everything considered is going to be less than 2 kW, but that's pushing pretty damn close to the 2 kW limit. 

 

With that kind of system, you're definitely going to need dual power supplies to power that thing. Running a power supply 80% or more of its total load capacity will wear down the power supply faster than running it 40-60% of its total load, plus you'll be hitting the efficiency sweet spot. Efficiency definitely drops when you go 80% or more.

 

My idea for the dual power supply setup would be this:

• 2 kW Super Flower Leadex Platinum 8Pack: 6 of the 11 GPUs + CPUs.
• 1.6 kW Super Flower Leadex Platinum: 5 of the 11 GPUs + all the storage.

Despite Pascal being pretty damn efficient when it comes to performance-per-watt and getting power consumption down, each GTX 1080 Ti is going to draw close to or exactly its rated TDP of 250 watts at stock when directly measuring power draw, like how PCPer does it. So 250 watts multiplied by 11 GPUs is going to be pulling a total maximum of 2.750 kW, which is why when I gave you the idea of dual power supplies, I divided the GPUs across the 2 kW and the 1.6 kW models.

 

To get two power supplies to start at the same time, you're going to have to build a special 24-pin cable with an auxiliary connector designed to interface with the PS_ON, GND, and PWR_OK (this may not be needed for certain models) pins, if I'm correct with how I would do dual power supply connectors.

 

There are dual power supply adapters out there if you want to use that approach, but I would build one yourself so you can customize the length for easier cable management. Either way works.

Edited July 19, 2017 by JurunceNK

[OddsCrazyStuff]

45 minutes ago, JurunceNK said:

To answer your question, yes 7 GTX 1080 Ti's with X99 will pull less than 2 kW, but you also have to consider storage (SSD/HDD RAID), RAM (number of sticks), and the board it'll sit on (boards with PLX switches or dual CPU sockets will need a maximum of 150 watts to properly operate) so the total system power draw with everything considered is going to be less than 2 kW, but that's pushing pretty damn close to the 2 kW limit.

So I would be fine under load, but not recommended.

 

Guess I need to start looking into dual PSUs then.

[Marinatall_Ironside]

50 minutes ago, OddsCrazyStuff said:

So I would be fine under load, but not recommended.

 

Guess I need to start looking into dual PSUs then.

Yes.

[Corsair Blake]

Personally, for something like this, I'd run dual PSU. I'd quite possible run a pair of RM1000i units. Hook up each PSU through USB to gather performance data and ensure proper operation per unit.