sli vram question

[Max_46]

if i had 2 980 4gb, does that mean i have faster vram?

 

[ryguybuddy]

No, same amount and speed of VRAM.

 

[photonboy]

Hi,
SLI has different options, but for now we tend to use the AFR method, or Alternate Frame Rendering.

With AFR, each GPU has its own pool of memory and processes a frame, with the OTHER card having a GPU and its own pool of memory processing the NEXT frame (same data on both sets of memory so 2x4GB = 4GB in that sense).

i.e.
GPU1-> FRAME#1
GPU2-> FRAME#2
GPU1-> FRAME#3
etc.

*In the future we're going to see the SFR option, or Split Frame Rendering where GPU's can work on the same frame. The video memory won't be identical either so you have up to the total memory. So 2x4GB = 8GB (max).

Google for more info if you want.

SFR will mainly be a DX12 and Vulkan option.

 

[photonboy]

Other:
I don't recommend multiple GPU's to most people. In general for now you want the best, single GPU you can afford. Not all games support multiple GPU's, and some that do can have issues such as stutter, judder etc.

The newer game engines appear to make AFR difficult to implement (not just a DX12 issue). For example:
http://www.pcgamer.com/uh-oh-batman-arkham-knight-wont-support-multiple-gpus-after-all/