Video Memory

[NoOp]

On 03/02/2009 03:38 AM, Ray Parrish wrote:

> 
> So... I'm not too sure what this is saying, as I do not know what the 
> memory ranges are specifying for sure. The second memory range matches 
> the reported 256 MB's reported by most utilities in Ubuntu, and dividing 
> the last memory range by 1024 only once matches 128 MB's but that 
> decimal number before division is only 131070.999658496 so if it's in 
> bytes it doesn't make sense to only divide once.
> 
> Anybody out there write device drivers for video cards?
> 
> I guess I'll just have to continue to be mystified as to how much memory 
> my card is actually using.
> 
> Later, Ray Parrish
> 

My _guess_ would be that your card is using shared memory and with your
512MB of ram it's 'Total Effective Memory' is 256MB. See:

<http://nvidia.custhelp.com/cgi-bin/nvidia.cfg/php/enduser/std_adp.php?p_faqid=243&p_created=1112744684&p_sid=9XVIqNrj&p_accessibility=0&p_redirect=&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9NDEsNDEmcF9wcm9kcz0wJnBfY2F0cz0wJnBfcHY9JnBfY3Y9JnBfc2VhcmNoX3R5cGU9YW5zd2Vycy5zZWFyY2hfbmwmcF9wYWdlPTEmcF9zZWFyY2hfdGV4dD1tZW1vcnk*&p_li=&p_topview=1>

You might find these of interest:
http://lwn.net/Articles/257417/
[Memory management for graphics processors]

Also, to get an idea of what each of your processes are using in the way
of memory you can use pmap. You'll find this interesting:

$ pmap `pidof compiz.real`
and
$ pmap `pidof compiz.real` -d |more

See: http://marc.info/?l=xfree-xpert&m=96835767116567&w=2
and 'man pmap'