I had Nvidia TNT2 M64 16MB PCI slot graphics card. Tested it in my ASUS A7V8X mobo (sempron 2300 cpu) and worked fine. I sold it on ebay and buyer said could get no picture on it (even after trying various things I suggested about conflicts) I got it back and found still worked on my computer- so card not dead. I tried it on a friends Hewlett Packard pentium 3 - 550mhz system and it worked on that also. I wanted to find a computer it did NOT work on to try to solve problem - and I found that on another borrowed computer I can not get a picture. It is ASUS p2B mobo with p3 - 450mhz cpu (it does work fine using agp card or a different PCI card). So the quest was on to try to solve it - well i have tried everything i can think of but no picture on screen. I have used SANDRA on my own (A7V8X) computer and the ASUS p2B and find the following differences: In mainboard info under PCI Buses: A7V8X: Version 2.10 , number of bridges 1, PCI Bus 0 PCI (33Mhz), Mulitplier 1/5x. The only difference on the ASUS p2B is multiplier is 1/3x. (i have no idea what this means) Further down is the Expansion Slot section which for the A7V8X includes: PCI 32bit +5v +3.3v PME , but on the P2B system that bit shows : PCI 32bit +5V. No mention of +3.3v PME. So is that significant? What voltage(s) does a PCI graphics card usually need?, do they vary on PCI (I know AGP do). I am thinking that the card has no pic because there is no 3.3v supply which perhaps it needs - Can anyone help / comment on if this is the key to it? - and how common this difference is. Up until now i thought that all PCI graphics cards were compatible with all computers (at least as regards actually getting an image on the screen). Thought/ comments please

"A PCI connector accepts a card edge. The PCI connector will have one or two keys [plastic gaps] in the connector. One key-Way indicates 3.3 volt operation [instead of 5 volt operation], and the other Key-Way indicates 64-bit operation. A 32 bit card would only have one key at most to indicate 3.3 volt operation." From this page - http://www.interfacebus.com/Design_Connector_PCI.html#f 98% of the population is asleep. The other 2% are staring around in complete amazement, abject terror, or both.

Thanks for the link. I got this bit of info from it: 32-bit 5V: Connectors with the notch farthest from the backplate 32-bit 3.3V: Connectors with the notch closest to the backplate 32-bit Universal PCI: Connectors with notches in both the 5V and 3.3V positions 64-bit 5V: 32-bit 5V PCI connectors, two key ways off-set right of center 64-bit 3.3V: 32-bit 3.3V PCI connector, one key far left, one just center right 64-bit Universal PCI: 32-bit Universal PCI connector, one key far left, two key ways off-set right of center .I also used google and read some other similar stuff. My card has the 3.3v notch and the 5v notch so is 'universal'it seems, so as far as I can make out it should work with 5v or 3.3v. I can only assume that the card has a fault in it - will work with 3.3v supply but not 5v supply. This PCI stuff seems a bit more complicated than i originally thought.