SunnyWaffleZ

Alright so it seems like one of the sticks WAS bad, as well as a DIMM slot. Which is peculiar because that wasn't the case a few weeks ago. I've opted to remove the two 13333 and keep the 1866. I may RMA it if I have time. Thanks everyone.

I'll see to that. Would be my third RMA with this board.

I know the RAM and the PSU are fine. It beeps 5 times if there's 4 sticks though, regardless of the type. I don't think it would start if it was the PSU.

System Specs Windows 7 Ultimate (64 bit) ATI Radeon 5770 Intel i5 2500k ASRock Z75 Pro3 2x G.SKILL Sniper Series 8GB (2 x 4GB) 240-Pin DDR3 1866 2x G.SKILL Sniper Series 8GB (2 x 4GB) 240-Pin DDR3 1333 COOLER MASTER Elite 460w My friend suggested that it could be the PSU, but I am doubtful since I (shouldn't) be near the 460W load. According to approximations from PCPartPicker and another website, I am roughly around 355W. It does not matter where I put the RAM or which stick combinations, since I am aware that they are running at different speeds. If there are 4 sticks in, it is a no-go. ABAB, AABB, BABA, BAAB, all sorts of combinations of stick placement fail, while simultaneously any combination using just 3 sticks work. Currently I have an xABA combination with the 1866 RAM being the A and the 1333 RAM being the B. I should also note it does not seem like I can overclock, as ASRock's pre-configured settings result in the same POST code. So just to reiterate, the sticks are all functional. The PSU is no where near its max output. The RAM slots are all working. However, to further complicate matters, only 8GB are being detected by the System. I am at a loss, and this has been going on for months. The only reason I didn't really concern myself with it is because I didn't care. The computer itself runs very well, allowing me to browse, play a video game, and listen to music all at the same time. But I do crash rather frequently, with no real indicator of why. It could be in the middle of just listening to music or in the middle of any game. I figured if maybe I could solve this problem the system might be more stable. Overheating is definitely not a problem, nor is air flow. I have 2x120mm front intakes, 1x120mm bottom intake, 1x120mm Hyper 212 EVO, the PSU 120mm exhaust, and a top rear exhaust (120mm) next to the EVO. Currently burning Ultimate Boot CD to see if that leads to a solution. In the meantime, can anyone assist me?