Does Vray benefit from SLI?

[Pretty Picture Girl]

Hi,

I have the option of one GTX 1080 Ti (= Benchmark 13776, 3584 CUDA cores, 11 GB Memory 250Watt, starting at approx 960Euro) ) or running two GTX 1080 (2x Benchmark 12770, 2560 CUDA cores, 8GB Memory, 180 Watt, starting at approx 509Euro).

What will work better in Vray from a render perspective?
Do I need them to run in SLI to boost VRAY render performance or can I run them both without SLI?
There is only one main monitor and an auxillary monitor attached, and my motherboard could only offer SLI via "Different SLI".
I hear SLI helps only in games and Vray can make use also of CUDA cores on both cards without SLI. Is that correct?

I am not gaming on this machine, Quadro is not an option.

Thanks,

Pretty

[savage309]

I hear SLI helps only in games and Vray can make use also of CUDA cores on both cards without SLI. Is that correct?

Yes, this is correct. Do not add SLI, V-Ray fill figure the multi GPU usage by its own.

1080ti is great for V-Ray GPU rendering. It is usually a good idea to have (small, cheap or even integrated) GPU dedicated for monitor only, so the GPUs can do just rendering.

Best,
Blago.

[Pretty Picture Girl]

Thanks Blago.
Great news!

So sounds like the two cards might be the better option

One more, would the increased VRam of a 1080 Ti offer real benefit over a standart 1080?

Thanks,

Pretty

[savage309]

It is always a good idea to have more RAM. In my tests 1080ti is >35% faster than 1080.

Best,
Blago.

[sheehan_partners_nm]

savage309
I am adding a similar question to this thread. My workstation (HP Z620) has a Quadro M4000. If I add a second one, will I benefit without buying a SLI bridge connector? Just by plugin in 2 cards will vray figure out automatically what to do?
Does it matter how the monitors (two of them) are connected to the cards? Both on the same or each card one monitor?
Thanks a lot!

[georgi.georgiev]

sheehan_partners_nm

Adding a second GPU to the computer will benefit the performance of V-Ray. As long as the operating system recognizes the configured GPUs, V-Ray will engage them when rendering. Additionally, you could use the GPU Device Selection tool to select which devices are used. It is accessible from the Rhino menu V-Ray > Tools or the following filepath - C:\Program Files\Chaos Group\V-Ray\V-Ray for Rhinoceros\tools\vray_gpu_device_select.exe

Regarding the monitors, it is advisable to have a dedicated GPU for the monitors so that you do not experience any hang ups while rendering.

[sheehan_partners_nm]

Thanks for the reply! Sounds good then. My understanding is I do not need to purchase the SLI bridge connector, just plug the second Quadro on the motherboard and good to go!

[georgi.georgiev]

Hi,

Apologies for missing to elaborate on the SLI component!

Please be informed that bridging GPUs with NVLink (NVLink enabled cards only) would have the benefit of shared memory, however, this is not the case with SLI. Furthermore, SLI in most cases would slow down rendering so it is not recommended.

[sheehan_partners_nm]

Hi,

Apologies for missing to elaborate on the SLI component!

Please be informed that bridging GPUs with NVLink (NVLink enabled cards only) would have the benefit of shared memory, however, this is not the case with SLI. Furthermore, SLI in most cases would slow down rendering so it is not recommended.

Perfect, very clear! Thank you so much