Matlab Dual GPU memory usage

Question

I have a Dual GPU card named Titan Z. I have Matlab 2016a trying to solve a sparse Ax=b equation set for different ' b ' values. Titan Z has two GPUs and 6 GB ram for each gpu

Here is the problem.

1. If I solve a Ax=b problem on 1 GPU, let's say a ' A ' matrix size of 2GB, Matlab copies this matrix to each GPU's vram. GPU-Z reports that each GPU has 2 GB of data and only 1 GPU is working
2. If I solve two Ax=b problem on 2 GPU, let's say ' A ' matrix size of 2GB, Matlab again copies this matrix to each GPU's vram twice. Now GPU-Z reports that each GPU has 4GB of data and two GPU is working simultaneously.
3. If I try to solve a '4GB' problem simultaneously Nvidia driver crashes due to insufficient Vram. But I can solve it on one GPU. not on 2 GPU simultaneously.

Problem is Matlab copies those matrices twice, when it is not needed, more interestingly, it does this when two GPUs uses exact same ' A ' matrix but different ' b ' vectors.

How can I solve this problem?

Answer 1

It is a bit late reply to my own question but here is the solution. Disabling multi-GPU mode in Nvidia Control Panel solved the problem. Basically it disables the sli and gpus can run independently. It was simple as that.