After learning that running fsx in dx10 mode can offload some of the ram useage to the vram I am wondering if a gpu with alot of vram can cure oom issues.  With the pmdg 777, photoscenery and fsdt airports I am right at the vas limit for fsx.  Would more vram help free up some vas space for fsx?

Yes. DX10 frees up about 500Mb VAS.

Yes but would adding even more vram free up more vas?

With DX9 the video memory counts towards the 32 bit VAS limit of 4 GB because of the way the memory is allocated.

 

With DX10 and later this is not the case, the video memory does not count toward the program memory VAS limit which is still 4GB. What you will see if you monitor your VAS is that you are able to get a lot closer to that  4GB limit than you could with DX9.

 

You can quite clearly see this happen in P3D V2 because there are many times that video memory being used + VAS being used is more than 4GB together. 

 

So the answer to your question is no it doesn't free any more VAS up. It gives you more room to use higher res textures though 

 

It can still help though to have a 3 or 4GB video card. Especially if you ever intend on running P3D V2