- Joined
- Mar 12, 2007
So in another post I was playing around with various GPU configurations trying to find a balance in PPD gain on the GPU's and PPD loss in overhead on the CPU.
550 TI about 11,200 PPD
I noticed when I added my 8800GT (5800 PPD) the 550 would drop to about 7000 PPD no matter the WU. Remove the 8800GT and we are back to 11,000. Swap it with the 9600GT (3800 PPD) the 550 stays over 11,0000.
Now the only possible explanation I can come up with is the 8800GT is PCI-E 1.0 and the other two are PCI-E 2.0 cards. I know the bus is backward compatible but I didn't think it would drop everything on the PCI bus to 1.0 speeds. Also I didn't think we were hitting the PCI-E 1.0 speed limits yet even on current high end cards. Does folding use up this much bus bandwidth?
550 TI about 11,200 PPD
I noticed when I added my 8800GT (5800 PPD) the 550 would drop to about 7000 PPD no matter the WU. Remove the 8800GT and we are back to 11,000. Swap it with the 9600GT (3800 PPD) the 550 stays over 11,0000.
Now the only possible explanation I can come up with is the 8800GT is PCI-E 1.0 and the other two are PCI-E 2.0 cards. I know the bus is backward compatible but I didn't think it would drop everything on the PCI bus to 1.0 speeds. Also I didn't think we were hitting the PCI-E 1.0 speed limits yet even on current high end cards. Does folding use up this much bus bandwidth?