Video Memory

Lucio M Nicolosi lmnicolosi at
Sun Mar 1 03:17:56 UTC 2009

>> No, that can't be right, because if I run the free command, it reports
>> 384 MB's of total physical RAM available to the system, plus the swap
>> file. I just think *something* is fooling all of these other programs
>> into reporting 256 MB's for the video card, and it's really only running
>> 128 MB's.
>> Here's the output of the free command.
>> ray at ray-desktop:~$ free -m
>>             total       used       free     shared    buffers     cached
>> Mem:           375        366          9          0          0         51
>> -/+ buffers/cache:        314         60
>> Swap:         1023        501        522
> Best Regards and sorry I couldn't help.
> Lucio

Back to business,

Made some tests w/ my board (onboard nvidia)

Independent of the amount of memory allocated for BIOS frame buffers
(from 32 to 512) the following is always the same (i.e. not correct)

lspci -v -s 02:00.0
02:00.0 VGA compatible controller: nVidia Corporation GeForce 8200 (rev a2)
	Subsystem: nVidia Corporation Device cb84
	Flags: bus master, fast devsel, latency 0, IRQ 22
	Memory at fd000000 (32-bit, non-prefetchable) [size=16M]
	Memory at f0000000 (64-bit, prefetchable) [size=128M]
	Memory at fa000000 (64-bit, prefetchable) [size=32M]
	I/O ports at dc00 [size=128]
	[virtual] Expansion ROM at feae0000 [disabled] [size=128K]
	Capabilities: <access denied>
	Kernel driver in use: nvidia
	Kernel modules: nvidia, nvidiafb

nvidia-xconfig shows either 256Mb or 512Mb of video memory depending
on the frame buffer size but only these numbers (i.e. not correct)

The amount of memory available ( F.I. cat /proc/meminfo) reflects yes
(by subtraction) the allocated frame buffer. (correct)

So it seems that it is difficult for linux to directly assess the
amount of allocated video memory, (try googling it, got some hits but
didn't take note) and most commands return questionable values.


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