The last time I had a dual GPU solution (6990 CF), the experience was horrible. 50fps with a single GPU was smoother than two of those cards running at 100fps.
I was looking for a resolution bump by getting a larger display, but I will need extra hardware to run it at 120fps. Do dual GPUs add as much input lag and micro-stutter as they did 3 years ago?
Dual GPUs: State of input lag + micro-stutter?
Re: Dual GPUs: State of input lag + micro-stutter?
i'm interested in this too.
which game do you have in mind?
which game do you have in mind?
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Chief Blur Buster
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Re: Dual GPUs: State of input lag + micro-stutter?
Microstutter of SLI has improved quite a lot. Especially with AMD "framepacing" improvements. But it is not perfect. NVIDIA is still superior for microstutter of multi-GPU setups.
Framerate affects GPU share of lag on a single GPU, in the input lag chain. For alternate frame rendering, Input lag tends to be equal to a single GPU at half framerate. This is because at 100fps, each GPU in a two-GPU configuration is taking 1/50sec per frame, rendering offset by about 1/100sec relative to the other. You get less lag at 75fps on a single GPU as a result. So doubling up your GPU, at best case, generally keeps your lag the same while doubling framerate. In the real world, it is usually worse. Split-frame rendering is used less often nowadays due to complexities of GPU special effects, making alternate frame the better performing choice.
If you care about microstutter+parallel it is a better situation today either way for both red and green than three years ago.
Framerate affects GPU share of lag on a single GPU, in the input lag chain. For alternate frame rendering, Input lag tends to be equal to a single GPU at half framerate. This is because at 100fps, each GPU in a two-GPU configuration is taking 1/50sec per frame, rendering offset by about 1/100sec relative to the other. You get less lag at 75fps on a single GPU as a result. So doubling up your GPU, at best case, generally keeps your lag the same while doubling framerate. In the real world, it is usually worse. Split-frame rendering is used less often nowadays due to complexities of GPU special effects, making alternate frame the better performing choice.
If you care about microstutter+parallel it is a better situation today either way for both red and green than three years ago.
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Re: Dual GPUs: State of input lag + micro-stutter?
Chief Blur Buster wrote:Microstutter of SLI has improved quite a lot. Especially with AMD "framepacing" improvements. But it is not perfect. NVIDIA is still superior for microstutter of multi-GPU setups.
Framerate affects GPU share of lag on a single GPU, in the input lag chain. For alternate frame rendering, Input lag tends to be equal to a single GPU at half framerate. This is because at 100fps, each GPU in a two-GPU configuration is taking 1/50sec per frame, rendering offset by about 1/100sec relative to the other. You get less lag at 75fps on a single GPU as a result. So doubling up your GPU, at best case, generally keeps your lag the same while doubling framerate. In the real world, it is usually worse. Split-frame rendering is used less often nowadays due to complexities of GPU special effects, making alternate frame the better performing choice.
If you care about microstutter+parallel it is a better situation today either way for both red and green than three years ago.
This is pretty much my experience. I have 2 Geforce 770s in SLI.
I haven't had any problem with stuttering but it adds a little input lag, especially with a frame rate cap. I disable SLI for games that I can max the fps out using a single GPU or if they are CPU bottlenecked.