http://h10025.www1.hp.com/ewfrf/wc/genericDocument?lc=en&cc=us&dlc=en&docname=bph07028

Now keep in mind that there is no electrical difference from 2.0 to 2.1. I will not document or debate this nuance.

Now that we know it's an i810 board and the interface goes right to said chipset let's find out what SiSoftware Sandra reported.

"Manufacturer : HP Pavilion 04
Model : P7492A-ABA 310n
... (much stuff)
PCI Bus(es)
Version : 2.10
No Bridges : 1
PCI Bus 0 : 32-bit PCI (33MHz)
PCI Bus 1 : 32-bit PCI (33MHz)
Multiplier : 1/3x"

It's 2.10

Done.

Now the only time this usually comes up is when a person has it locking up. The usual cause is a clean install of windows and forgetting the Intel i810 drivers.

Bob