I'm not new to PC builds but components are a LOT more powerful than 5 years ago on my last big build and I typically can sort out all my issues as I go but I need some assistance with this one since I have not had hardware failures before. New build and all hardware components in my profile. Issue I am having is when I tested the game GTAIV after playing many other games (Borderlands, NFS, Gas Guzzlers etc) I started to have lockups of the video card. I have 3 monitors connected to this cars (only one for gaming obviously) with the main 42" monitor connected via HDMI and the 2 smaller monitors via DVI. I have CPU and all components running at stock speeds with no overclocking. When I play GTA I can play for about 10 minutes before aall 3 displays will turn to rainbow colours and then all go blank. Sometimes the PC will reboot and sometimes it will be "frozen" but the game audio is still there so this is where I believe I have a video card issue and probably power or heat related. I have a system monitor running for all CPU and GPU temps while I play and I note that the GPU reaches about 70c when the cutout occurs and the CPU is at about 42c. Looking at power consumption of the P/S it seems the system is only demanding 400W max from the supply so there is loads of headroom. Where I believe I may have something wrong with my installation is the card has 2 PCIe power connectors on it. My card has 2 x 8pin connectors but Gigabyte specs say that a 6+8pin connector are fitted. I have a SINGLE 8 pin power feed from my PSU which has a TWIN 8 pin at the end and I have this single power feed supplying the card. I have not worked with a monster card like this and I am thinking I should be using 2 separate feeds from the PSU? I am mainly asking for ideas while at work to try and get a plan for when I start troubleshooting.