On 07/30/10 03:37, Nick Bowler wrote:
On 2010-07-29 11:30 -0600, Luke Palmer wrote:
If you are trying to redraw in realtime, eg. 30 FPS or so, I don't think you're going to be able to. There is just not enough GPU bandwidth (and probably not enough CPU).
Updating an 800x600 texture at 30fps on a somewhat modern system is absolutely *not* a problem.
It depends. Updating 800x600 screen at 24-bit color 30 times per second requires 800*600*24*30 = 345600000 bytes/s = 329 MB/s which is larger than the size of typical Video Memory, and the first version of PCI Express (introduced 2003) is only 250 MB/s/lane. While the bandwidth and Video Memory size is sufficient to transfer 329MB/s, it is quite near to the limit, especially if you have another programs running, which may cause some resource contention or if you used some memory-heavy techniques like double buffering. You're probably quite safe if you have PCI Express version 2, have over 1GB RAM, and a good Video Card. You're probably quite screwed if your VGA uses a Shared Memory Architecture (i.e. it uses RAM for video memory, this easily causes resource contention).