The graphics card that integrates your processor, what VRAM does it use in your PC?

It’s pretty well known that the iGPUs currently on the market are a huge leap forward from what we saw just a few years ago, but this is bringing a very interesting consequence to deal with: the performance of your “supposed” VRAM. How does the processor allocate graphics memory to the iGPU ? And above all, how much does performance depend on this type of memory?

Integrated graphics cards on both motherboards and processors have always depended on external memory to be used as video RAM or VRAM, but for some time now the assignments are different and it is convenient to understand why.

The graphics card that integrates your processor

Your iGPU is still using system RAM as VRAM

And it does so for a very simple reason: the benefit/cost ratio. The processors that have iGPU and that are not called as such APU because the CPU part prevails over its opposite, usually have a low-level graphics card, competent for certain tasks yes, but not for gaming as such. For this reason, and although this type of device could have HBM memory to its credit and manage to trigger performance due to the final costs for the price of the processor, this is not done.

AMD-HSA2

But it is not done for APUs as such and for the same reasons. The technology is there, it’s mature, but it’s expensive to implement and no one in their right mind would pay the extra cost, so the range of processors would end up dying compared to that of the rival. The solution to have VRAM? The usual one, the one of a lifetime: use system RAM , that is, DDR memory as an information exchanger.

The difference is the way of assigning it by your PC, since in the past a very small part was reserved for VRAM, only a few MB, until the potential of the iGPU took off, the games demanded more video memory and it had to change the system.

Graphics APIs and the importance of speed

Some APUs still allow maximum allocation from the BIOS/UEFI, but as such this is tending to go away because Shared Memory is doing a better job these days thanks to DX12 and AMD and Intel drivers.

Normally the parameter that defines the VRAM in BIOS is the DVMT Pre-Allocated VRAM, where as a rule it leaves up to 4,096 MB assigned. Windows and DX12 using what is known as hUMA (particularly at AMD) or Unified Memory Architecture. This system shares the PC’s RAM memory with the iGPU and if our processor and platform allow it, it should be in AUTO, since it will be, as we say, the system that manages to increase or reduce the size of the frame buffer through a consistent memory model and bidirectional (HSA in AMD).

UMA

The proportion of RAM that is used is determined in part by the allocation as shared memory, which at the same time overlaps with Windows Virtual Memory in the event of a lack of RAM in the system. The thing to understand here is that the API and driver will oscillate the amount of VRAM allocated in a ratio between 1:4 and 1:2 , depending on the case.

That is, if the system requires 1 GB of VRAM for the iGPU, our PC should have 4 GB in the best case and 2 GB in the worst. It is far from being an exact rule, as we say it is managed in a completely open and free way (if we indicate it in AUTO ), so the VRAM of your iGPU continues to be and will continue to be the system RAM on PC.