Hi, as you know, nVidia drivers are a bit crippled to not support HBR2 mode via DisplayPort on WinXP on DP 1.2 capable VGAs (even the same version of drivers for Win7 can do it) so you stucked at max. 3840 x 2160 @30 Hz. But I found this interesting thread: Windows XP (x64) and very high resolutions with NVIDIA (and now: ATi / AMD) – The GAT at XIN.at where the user Yas presented his hack to modify HDMI output pixel clock artifical limitation. I tried this hack myself on GTX970 and it enabled me to go up to 3840 x 1600 @89 Hz (pixel clock ~600 MHz). But there’s another artifical limitation to 1600p so more hacking would be needed to break this stupid limit and enable full 3840 x 2160 @60 Hz. Anyone would be interested? I belive that checks would be somewhere near offsets that Yas described. I’m too busy with real-life stuff…