I purchased an ATI 9600SE video card about a year ago, and I've just started to experience serious lagging problems with online gaming (even when both me and other players online have nice low pings) and minor lags with non-online games. I just purchased a new hard drive and reinstalled my XP Pro OS, and I also updated my Bios plus the driver for each physical component. Even with all that done, I started to experience lag!! Now, I'm talking about games such as Wolfenstein Enemy Territory (which you can run on a normal laptop), with minimal graphic requirements!
I don't understand it, I contacted ATI personally and checked few other things, but the problem seems to exist still. I know it's not a top-of-the-line video card, but it played Far Cry (high graphics) without a problem at medium level! I updated my chipset driver, graphics driver and all other drivers I can think of. Is it still a software problem? It's a retail graphics card from a store, so it's not a refurbished or used card, it shouldn't be physically malfunctioning.
Specifically, the lags are present during intense gaming, such as sitting on a train watching the train moving with rhythmic lagging (patterned), and I also see other people lagging, with nice low pings!!!! Especially when I get into a gun fight (duel) with another player, I see they lag heavily, but myself not lagging to them.
I hope that's detailed enough to eliminate common problem possibilities, because it's not a common problem (at least I don't think).