request for comments: how many vram do you grant your APU?

[jpsollie]

Hi everyone,

I accidentally came by the Smokeless_UMAF project,
which is extremely useful for my laptop:
HP limits all its Amd APU laptops to a =2GB VRAM,
which is a lot for someone who's never gaming nor using multiple monitors.
But ... how much vram does a APU actually need these days?
You can say 2G is too much, but is 1G the sweet spot for regular desktop work?
or is 512MB a better idea?
I see, using radeontop, at normal office work, the GPU is using 3-400MB VRAM.

What would you say that a "non-ridiculous" amount of VRAM is these days?
_________________
The power of Gentoo optimization (not overclocked): [img]https://www.passmark.com/baselines/V10/images/503714802842.png[/img]

[logrusx]

Integrated display: 2560x1600;
External display: 1280x1024;

4k YouTube video playing on the integrated display, full screen;

VRAM in use: ~1.6G

I don't think 512MB is a good choice.

p.s. the integrated Vega (Ryzen 7 5800H) cannot play a 4k video on a 4k external display. Not because of memory but because of lack of iGPU computational power. If I want to do that I must switch on the nvidia card.

p.s.2 it takes 1GB without playing anything in the browser. So unless you're really short on memory, I wouldn't recommend cutting the vRAM for the iGPU.

Best Regards,
Georgi

[jpsollie]

[logrusx]

It is hardware accelerated, it just can't do it over HDMI. It may have something to do with the outputs being driven by the dGPU. I'm sure they are, because when I completely power off the dGPU, they are inactive.

Best Regards,
Georgi

[NeddySeagoon]

jpsollie,


For 2D, the absolute bare minimum is two pixel buffers.
That's X * Y * 2 * (colour depth bits /4) bytes.
Note that 24 bit colour uses 32 bits as there in no way to address a 24 bit quantity on x86/amd64.
Many GPUs won't like the bare minimum as they insist on working with X and Y that are integer multiples of 8.

Some off screen space in good too, as GPUs like to compose primitives in the GPU RAM and move them to the pixel buffer, as required.
Copying a region of RAM (Bit Blitting) is much faster than drawing it and at 60Hz refresh, there is only 16.666 ms to render each frame.

With 3D, it gets much more complicated. However, if you don't allocate enough Video RAM, the APU will borrow some main memory.
This is a bad thing, as the main memory access is slow.

It comes down to your usage.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[jpsollie]