A month ago I've OC my I7 920 from 2.67 to 4.0 and also upgraded my memory from 4GB 1333MHZ to 6GB 1600MHZ and I'm using the Vantage ALC for CPU cooling...Evrything was working fine and I was able to run prime95 for 8hr without getting any errors or warnings but recently fsx have been freezing from time to time but it doesn't last for long..only a few seconds...below are my OC infos...is there anything that needs to be changed that will fix my freezing issue.Ai Overclock Tuner.....................[Manual]CPU Ratio Setting......................[21.0]Intel® SpeedStep Tech............[Disabled]Xtreme Phase Full Power Mode...........[Enabled]BCLK Frequency.........................[191]PCIE Frequency.........................[100]DRAM Frequency.........................[DDR3-1531MHz]UCLK Frequency.........................[3063MHz]QPI Link Data Rate.....................[Auto]CPU Voltage Control....................[Manual]CPU Voltage............................[1.22500]CPU PLL Voltage........................[1.80]QPI/DRAM Core Voltage..................[1.21875]IOH Voltage............................[1.12]IOH PCIE Voltage.......................[1.50]ICH Voltage............................[1.20]ICH PCIE Voltage.......................[1.50]DRAM Bus Voltage.......................[1.64]DRAM DATA REF Voltage on CHA...........[Auto]DRAM CTRL REF Voltage on CHA...........[Auto]DRAM DATA REF Voltage on CHB...........[Auto]DRAM CTRL REF Voltage on CHB...........[Auto]DRAM DATA REF Voltage on CHC...........[Auto]DRAM CTRL REF Voltage on CHC...........[Auto]Load-Line Calibration..................[Enabled]CPU Differential Amplitude.............[800mV]CPU Clock Skew.........................[Delay 300ps]CPU Spread Spectrum....................[Disabled]IOH Clock Skew.........................[Auto]PCIE Spread Spectrum...................[Disabled]C1E Support............................[Disabled]Hardware Prefetcher....................[Enabled]Adjacent Cache Line Prefetch...........[Enabled]Intel® Virtualization Tech...........[Disabled]CPU TM Function........................[Disabled]Execute Disable Bit....................[Enabled]Intel® HT Technology.................[Enabled]Active Processor Cores.................[All]A20M...................................[Disabled]Intel® SpeedStep Tech............[Disabled]Intel® C-STATE Tech..................[Disabled]Intel Core I7 920 @ 2.67 OC 4.06GB of RAM DDR3-1600MHZ Sapphire Radeon 5870 1GBASUS P6T S.1366 INT X58/ICH10R ATX 3PCIE X16CORSAIR PS CMPSU-850TX 850W POWER

How are the CPU temps? I have my I7 950 clocked to 4ghz as well, and just recently I have been getting BSOD's. I think it mostly has to do with the summer like temps we have been getting here on the east coast, and my cpu is running hotter than I would like!Also I am surprised that you are able to get to 4ghz with that low voltage? I have to run at 1.25 to get stable.Also you should disable hyper threading as FSX and, many other applications dont benefit from it anyways.I hope you find a solution.Chris,

...is there anything that needs to be changed that will fix my freezing issue.

Yes! Post a HARDWARE question in the HARDWARE forum, not the FSX forum.

try running Memtest86, and see if your memory is OK.