If it's a PC-Chips M810LMR, then there is some performance sleeping in it - hop over to the PC-Chips Lottery site, and grab the "tweaker's BIOS" for it. That's the same BIOS as shipped, but with many chipset configuration tweaky bits unhidden to play with. People have been reporting performance increases from nil to 35 percent, depending on what they do with it.
Besides, a TNT2-M64, also being a very memory bandwidth compromised "budget" solution, doesn't do much better in performance than does the integrated unit ...
regards, Peter