I had a good run but ever since getting to the fire temple it’s crashing every 5 minutes
That’s actually a misconception, though one that was often propagated so it stuck, unfortunately.
The Steam Deck will dynamically allocate video memory - way below 4GBs, or even larger than 4GBs, regardless of what you set as the UMA framebuffer setting. And it will change this allocation in real time, during each frame, as it monitors memory pressure.
The UMA buffer will indeed give a default “the GPU would like to report that 4GBs of memory are mapped to itself when the driver loads” but the CPU can (and will!) immediately ignore that as soon as needed.
Don’t believe me? If you got 15 minutes to do a little experiment, try setting it at 256MB. 256MB for a device running modern games? No way! It won’t get past the loading screen, right? Well, it will, and the performance will be quite literally identical to setting it at 4GB.
Addendum: some games give warnings of “Your system do not meet the minimum requirements of VRAM” when running on systems with APUs, in that particular case, setting a large UMA buffer will probably work to bypass the warning… But again, performance is similar.
Theoretically I agree with you, but I finally broke down and changed mine due to some instability and I haven’t had a problem since.
It’s completely possible that’s just placebo since my understanding of how it should work says you are right.
Oh, I’m not claiming you’ll get any problems - you won’t, don’t worry, you can set it or leave it be without issues. You don’t have to revert your setting, sorry if my comment gave that impression.
But it will not give you any benefits, really. It’s like setting a different wallpaper - you can do it, it won’t harm anything, but it won’t actually improve games.
My understanding on the advantage for the VRAM change is that RAM gets priority over VRAM. If the systems needs more RAM, it will allocate the VRAM to RAM, and then reallocate back to VRAM, over and over. Increasing the minimum VRAM both keeps the VRAM from dropping below 4GB during high RAM demand and reduces the system swapping RAM between VRAM and RAM. That swapping back and forth can cause stuttering, which is the main thing the VRAM change is trying to fix.
I don’t fault your logic, but unfortunately (and I really do mean unfortunately) that’s not the case. The CPU gets absolute priority and can quickly take memory for itself.
Perhaps on other APU architectures that’s not the case, I wouldn’t know, but with the Steam Deck the CPU is always the maximum priority for memory allocation.
@kadu @Fubarberry FWIW the author of cryoutilities has done benchmarks and figured that increasing the default on the Deck does improve performance in some games slightly. He claims that introducing the swapfile also mitigates any potential disadvantages.
