Texture Download Performance

[Nigel J]

Hi All

I'm writing an application that does a lot of texture download, so I've been trying to get my test app to get close to the benchmark numbers that I found in the pdf that is contained on this page:

http://developer.nvidia.com/object/f...transfers.html

My machine is a dual CPU dual core Opteron box from Boxx systems (7400 model), with two Quadro 4500G cards running SLES 10. I'm hoping to attain similar figures to the those in the last line of table 1 on page 3, but I'm not!

In RGBA mode I'm getting consideably better numbers roughly 950MB/s almost twice the number, but for BGRA I get just over that at about 1000MB/s which is only 40% the number that is in the table.
I'm aware there are many differences between the two setups, but I'm confused as to why my benchmarks are so close together given that the table clearly shows BGRA texture download being between 3-5 times the speed of RGBA...

Any idea as to why I might be seeing these strange results?
Anyone know any methods for getting closer to the BGRA number?
(I'm using the PBO's as suggested in the pdf file)

Is the benchmark app that produced these figures available to download and try out at all?

thanks

Nigel