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Why Aero requires so much VRAM?

Posted: 14. Jul 2011, 13:06
by Technologov
Other 3D usecases, WineD3D + OpenGL use VRAM dynamically, so you can assign just 16 MB of video RAM initially to the VM.
The rest will be taken from physical video card somehow.

Why does Aero needs much bigger assignment up-front ?

Re: Why Aero requires so much VRAM?

Posted: 15. Jul 2011, 15:50
by misha
In two words, the big amount of guest VRAM is required to enable fast guest->host ogl data transfers over guest VRAM, to avoid extra memcopies, etc. This is especially critical for fast texture data transfers critical for Aero.

Re: Why Aero requires so much VRAM?

Posted: 15. Jul 2011, 15:58
by Perryg
Does it improve if you set the memory to the MAX (256)? I know the 256 is for multi monitor but will using the max help in single monitor mode or is anything over 128 a waste?

Re: Why Aero requires so much VRAM?

Posted: 15. Jul 2011, 17:05
by misha
Perryg wrote:Does it improve if you set the memory to the MAX (256)? I know the 256 is for multi monitor but will using the max help in single monitor mode or is anything over 128 a waste?
No, it should not help unless you're going to run many ogl/d3d applications simultaneously.

Re: Why Aero requires so much VRAM?

Posted: 15. Jul 2011, 17:11
by Perryg
I suspected as much from looking at the source, but wanted to get the final determination. Thank you!

Re: Why Aero requires so much VRAM?

Posted: 17. Jul 2011, 17:37
by Perryg
I have tested this some more and found that with 128MB of vRam as long as you do not change the screen size it works fairly well. But if you change the screen size using the (host+F) toggle or the min/max on the toolbar it refuses to draw the screen unless you save state and then start again.
I set the vRam to 256 and it allows the screen resize (host+F) or even mouse drag to operate as it should.

System Ubuntu 10.10 x86_64 (no VT-x) 1024 base memory. win-7 pro x86_32, Beta-3 GAs, single monitor.
Windows-7-2011-07-17-10-18-50-128MBvRam.log
With 128MB vRam
(88.74 KiB) Downloaded 23 times
Windows-7-2011-07-17-10-22-33-256MBvRam.log
With 256 MB vRam
(63.37 KiB) Downloaded 26 times