Integrated/discrete GPU and memory

[Yoshimura]

For device with integrated and discrete GPUs, does the integrated GPU can use the graphic RAM?

 

[jackoatmon]

the iGPU using the dGPU's vRAM ?

is that what you mean?

nah i would be very, very surprised

defeats the whole purpose of the vRAM, which is it's right here on the chip with insanely fast bus speed

or so my moderate level of understanding would lead me to believe

 

[mikeo007]

The iGPU will only share system RAM. It does not have access to the GPUs on package vRAM.

 

[Yoshimura]

the iGPU using the dGPU's vRAM ?

Yes, that what I mean.

This would prevent the iGPU to use the system memory as vRAM.

Maybe the iGPU could still access it at a normal bus speed?
[doublepost=1479140626][/doublepost]

The iGPU will only share system RAM. It does not have access to the GPUs on package vRAM.

So every time the system switches to the iGPU, the system memory drops?

 

[mikeo007]

So every time the system switches to the iGPU, the system memory drops?

Not in any meaningful way. It will only use as much RAM as it requires, and any task that requires more than a basic amount of vRAM is probably going to engage the dedicated GPU.