Hello, I've been searching for a solution to fix my problem when I stumbled upon this forum, which seems to be populated by people who know their stuff ! I hope you guys will be able to help me resolve my IMO strange problem... So here's the deal, I've installed the Catalyst 8.4 AGP HOTFIX on a fresh clean install of Vista SP1 32bits and then Rivatuner 2.09 to fix the default clock rate and the AGP speed. (I need to put the speed to 4x because at 8x, any 3d applications will freez my comp, but more on that later...)After the obligatary reboots requested by the installation of those 2 things, I decide to launch a game to try out DX10 stuff (CoH: Opposing Fronts.) and ZOMG, I see the intro logos lag before me. Once at the menu, same thing : everything is slow...I decide to launch another game, to see if the problem is widespread (Hellgate London) and SURPRISE, lag-fest at intro logos/menu. Once and for all, I want to know if this really is a problem with all 3D applications : I launch the 3D chess game whom came with Vista. Of course the thing lags as hell, even though this isn't the kind of game which demandes a LOT from a graphic card. As the stuborn chap that I am, I launch the Catalyst Control Panel to check out the settings. I almost let out a loud WTF? when I saw that the 3D preview windows ran smoothly and without any lag.... Bafled by this newfound discovery, I try a little experiment : I will survey the GPU usage feed through the HARDWARE MONITORING tool from Rivatuner. First test: I launch the chessgame. Another WTF goes by silently in my head as I look at the feedback. The GPU USAGE is rather inexistant, barely reaching 0.26%. No wonder even this game lags. Second test: I launch the Catalyst Control Panel to look at the 3D preview windows. And uhm, guess what fellows? The GPU USAGE returned normal scores, proving that the graphic card was working on it. Shortly after that, I made the usual "Uninstall drivers/Driver cleaner/Reinstall drivers" sweep, but still the same problem...... I noticed something interesting when I activated the Aero theme : For those who are not aware, the Aero theme from Vista enables some 3d features for the desktop using the GPU. Well when I was under that theme, because my GPU was being used, I could play the Chess game smoothly. But I had no luck with my other games (Company of Heroes and Hellgate London) because in SP1, Vista will automatically disable the Aero theme when you launch a game application.... Is there some kind of registry hack that could prevent Vista from disabling Aero ? (Like it was done under the first iteration of Vista.) Another little discovery I've made : I was in the regular Vista theme (thus no Aero GPU usage.) and noticed that when I reduced the window of the Chess game, it would run smoothly. However, putting back the window at maximum size reput the thing into lag mode. I've tried running my 2 games in windowed mode, however it did not change anything. Still the no GPU usage laging problem.... I've tried many drivers, old and new, inlcuding the newest 8.5 Catalyst but still no luck so I really think it might be a problem with the motherboard's AGP driver... So mates, what the hell do you think is going on right there ? I'd like to precise that the card works under XP! (Even though I had trouble installing the drivers like most people who own this damned card.) Which brings me to another question : My motherboard is AGP 8x compliant, but why won't the card function under 8x mode ? Has it something to do with voltage ? In my mobo's manual, it is said it supports 8x at 0.8v.