View Full Version : learning_VAR performance

11-01-2002, 01:40 AM
I get 6.8 MTri/sec on GF4ti4600 P4-2200
under win2000 32bpp detonator 30.82.
Is it OK? I would expect much better performance.

11-01-2002, 07:35 AM
With my GF4TI4200 I get 45 MTri per second with one texture and one directionnal light... There are many program to benchmark your 3d card but I think your code isn't well optimized... don't forget to store indice buffer in RAM not in VRAM or AGP.


11-01-2002, 10:46 AM
Given that we're talking about the Learning VAR program from nVidia, I don't think they're doing something stupid. After all, it's nVidia's demo.

Your performance is low. I, for one, understand that the demo's interface isn't the easiest thing in the world. Maybe you should try increasing the number of polygons you throw at the card (if you haven't already). Generally, the best way to use learning_var to measure performance is to find the number of triangles that gives you the largest tri/sec number.

11-02-2002, 11:33 AM
Hmm.. I've tried this demo on three olmost identical system (same motherboard, CPU and videocard) and I got three different results:
1 - win2k 6.8 Mtris/sec and video driver config page says I have AGP bus but in PCI mode

2 - same machine but under linux. I get 24 Mtris/sec and /proc/drivers/nv/agp/status says I have AGP 4x with fast writes and SBA enabled

3 - another machine but under windows XP I get 22 Mtris/sec driver page says I have AGP bus

4 - another machine under win2k I get 39 MTris/sec and driver says I have AGP bus.

Interesting how should I configure AGP speed under win 2k and why it works in PCI mode on the first machine? Why I get only 22 Mtris/sec in 2-nd and 2-rd case?

11-02-2002, 11:48 AM
If you don't have the correct AGP drivers for your chipset, then your AGP bus will run in PCI mode, and be very slow. This is actually fairly common -- there's even OEM PCs you can buy that come without proper AGP drivers! (Hi, Micron!)

The most common reason by far is to upgrade the motherboard in a computer that retains its hard drive and OS install, and then not actually bothering to install the driver CD that came with the new motherboard.

The second most common reason is building a machine with a motherboard/chipset that's newer than the version of Windows you're installing. Win98 is ancient by these standards. Even WinXP is lacking some newer chip sets, such as VIA KT400 or the SiS AGP 8x one.

There's also the people who upgrade 16-bit Windows to Windows XP, and don't know to go get new OpenGL drivers; these people end up with software OpenGL and become very unhappy.

Because these problems are so common, we have the installer for our product actually detect these problems (and some other known ones, such as DVA=0 in WIN.INI on 16-bit Windows) and tell the user what to do.