View Full Version : Display Lists and VAR

12-25-2002, 03:34 PM
Thanks in advance for any help...

Simple question - Do the current nvidia and ati drivers store display lists on the hardware? Or is using VAR or some other extensions the only way to get vertex data on the card?

Thanks again

12-25-2002, 05:31 PM
Display lists are reasonably well optimized.

However, I've said it before and I'll say it again: storing geometry in VRAM is seldom the best possible place for it. Usually, your program is fill rate limited. When it's fill rate limited, that means that you're bound on throughput of reading textures, and reading and writing framebuffer data, to/from the VRAM. Adding additional strain on VRAM by putting geometry in VRAM seems like it would hurt.

Meanwhile, AGP 2x will give you 0.5 GB/s throughput (and faster versions go up from there) for *FREE* for your geometry. Supposing you store one set of position, one set of normals, and one set of s,t all in shorts, for a total of 16 bytes per vertex, this means you can push through 33 million vertices per second, or over a million vertices per frame at 30 fps!

Even adding another texture coordinate, plus a tangent and binormal, you will get at least half a million vertices per frame through AGP 2x. Hopefully your triangle needs aren't quite there yet :-)

12-26-2002, 04:27 AM
VAR is also great for dynamic geometry. And you could decide if you use video or APG mem.