Today,I took my 7950GT AGP 512MB to exchange a 7950GT AGP 256MB,and install it in win98 again and then the test result was wonderful .Because it was successful to install it in win98 with 3G RAM which use himemx.exe. So now,I can sure that win98 can't handle VideoCard with 512MB VRAM with AGP actually(whether the PCIE can work or not ?). I tested the VideoCard with 3DMark2001 & 2003 in win98, and both of the test results are all pass,it works fine.The only problem is like the other ones who use MDGX's Driver with Nvidia 7-Series VideoCard,the win98 can't shutdown normally but can restart.So it's not a serious problem for me,because I can restart my PC to WINXP and shutdown it. Finally,here are some pictures that captured from my win98 system about the 7950GT AGP 256MB test result . 1. The win98 install 7950GT AGP successful . but in Nvidia Control Panel recognizes as unknown. 2.3DMark 2001's test result. 3.3DMark03's test result.