[ltp] cuda and the quadro nvs 140M, memory allocation issues

[Richard Neill]

Micha Feigin wrote:
> I'm trying to learn cuda programming (run programs on the gpu) under my t61
> with the quadro nvs 140m card.
> 
> I keep getting memory allocation failures and anything but very small
> allocations.
> 
> I don't know if it's related but it seems that the card is wrongly reporting
> the amount of memory it has.
> 
> AFAIK it should have 256MB memory. nvidia settings shows though that it has
> 512MB and I don't know how to check what it's saying.
> 
> I'm also guessing that X is taking too much of the video memory but not sure.
> 

At a guess, your card is pulling the common trick of claiming a large 
chunk of regular system RAM, and using it as a (lower-bandwidth) 
addition to the card's main RAM; you can usually switch this off in the 
BIOS.

You probably need
     1600x1200  pixels
x   2 screens (if dual display)
x   4-bytes per pixel for 32-bit RGBA colour
x   2 for double-buffering, if you want 3D accel

=  32Mbyte minimum for your actual system. So I'd expect you can 
allocate 128M safely for your experiments.


Richard


P.S. For amusement...don't actually do this:
http://thedailywtf.com/Comments/The-Skys-the-Limit!.aspx?pg=2