Will Crossfire/SLI benefit Compute Shader performace?

Question

I'm digging into DX11 Compute Shaders. And I wonder if there will be any performance increase with adding one more video card with Crossfire/SLI. Or adding one more video card without using Crossfire/SLI.

Has anyone experimented with this?

Answer 1

I run a system with two Nvidia Maxwell archietcture GPU's. I don't use Crossfire/SLI.

Crossfire/SLI won't affect the Shader compute performance per-se. Crossfire/SLI manipulates the image frame rendering output do one of several things:

1) Render a partial frame on different GPU's 2) Render alternative frames on different GPU's 3) A combination of 1) and 2) 4) Improvements in anti-aliasing

See http://www.hardwaresecrets.com/article/SLI-vs-CrossFire/391

Crossfire/SLI is useful for improving rendering performance of images, games etc. It does nothing to improve the compute performance.

Adding an extra video cards without Crossfire/SLI, will benefit compute performance, if you can partition the work across the multiple GPU's without incurring too much overhead. This can be done with CUDA and OpenCL by creating multiple device queues and queuing work to each device. I don't know if DX11 Shaders can do this?