blitting to system RAM from VRAM

  • Thread starter Thread starter postman
  • Start date Start date
P

postman

Is there a way to blit from VIDEO RAM to SYSTEM RAM? I know it is not
a recommended way of doing things, I just wanted to find out if ATI
and NVIDIA card's hardware blitter supports it.

Thanks
 
postman said:
Is there a way to blit from VIDEO RAM to SYSTEM RAM? I know it is not
a recommended way of doing things, I just wanted to find out if ATI
and NVIDIA card's hardware blitter supports it.
Click to expand...

I'm sure they do, as a lot of their low-range cards seem to use system
memory to increase their video memory size. I think Nvidia calls it
TurboCache, and AMD calls it HyperMemory.

Yousuf Khan
 
I'm sure they do, as a lot of their low-range cards seem to use system
memory to increase their video memory size. I think Nvidia calls it
TurboCache, and AMD calls it HyperMemory.

        Yousuf Khan
Click to expand...

The system memory is used for buffer object storage. But that aside,
the problem isn't transfering the data but the resolve needed to
acquire the correct data to transfer. If the client cannot return
until the data transfrer is complete, this can consume considerable
amount of CPU time polling for the result. If this is done by sending
a request with non-blocking query, it's doable, but there isn't public
API for that.

Hardware can do what the OP is asking, but it needs someone to want to
write the software support.. FWIW, the compute shaders in coming APIs
and hardware might have something useful for this kind of activities.

p.s. I am assuming that the OP wants rendered image. If not, I'm so
sorry. =)
 
Back
Top