This is a weird one. I have been having annoying problems with this rig for the past couple of days after more than three years of heavy use and rock solid reliability. System is as follows: ASUS P6T Deluxe (the first one, not the V2, not the P6TD) i7 920 @ 3.8 GHz 12GB Corsair Dominator GT (6x2GB modules) This machine has ran the i7 at 3.8GHz without issue, but is capable of 4GHz as well. I dropped it to 3.8 when I upgraded to 12GB in order to get the memory frequency right so I could run all 6 modules in the board. That worked out to be about 1600MHz which isn't bad for a fully populated X58 board. For some reason, a couple of days ago I decided to see if I could get it to run the 12GB at over 1600MHz and the chip at 4GHz. It turns out that it can't, constantly BSODing at or before the windows desktop, so I reloaded my old OC profile, checked the settings and rebooted it. Everything was going fine until I realized that the board was only picking up 8GB of RAM - a problem I experienced when I initially installed the additional 6GB of Dominator GT and tried booting it @ 4GHz. I have since tried everything to enable Windows to detect all 12GB including manually entering timings, upping the QPI voltage, dropping the BCLK and even stock X.M.P settings, but nothing I've tried so far has worked. On top of this problem - and I don't know if this is related or not - I now have an annoying problem where Windows will detect an "unknown device" connected to the USB2 ports on the board, then constantly and randomly play the Windows 7 "device connected, device disconnected, device failed to connect" sounds. I have disconnected everything from the system except the USB mouse and keyboard, but it still persists. I've had to disable these sounds in Window to stop it driving me mad when I'm trying to use the computer. This is now little more than an overspec'd office PC that I occasionally do video editing and CAD on, but it's strange that it has started doing this all of a sudden and I still hate to see it causing problems like this after so much reliability. I hate to say it, but it feels like my trusty P6T board might be starting to let go. Any ideas?