Ok, so the unthinkable has happened. My PC has decided to throw an epishit, and quite possibly even present me with a challenge to resolve as the error could be one of 3 components, what makes it all the harder is these 3 components can all exhibit the same sign I currently have. The point in this thread is largely for reference for anyone who may need it. Now some details; Problem description: Random restarts & varying BSODs. Detailed analysis: With CPU & RAM at stock all is well. Lowering multiplier to 8x or 7x and Increasing FSB to 300MHz results in the random restarts & BSODs. Increasing multiplier to 10x and FSB to 250MHz makes no difference. Unlikely to be a faulty Mainboard as if that were the case, the 50MHz FSB drop should show an increase in stability at least. However the possibility is not ruled out. Due to the FSB change if the CPU memory controller was dying it also should of backed that up, however there was no change, ruling the possibility out of that, however this is still an option. Of particular note is the fact my TCCD even @ stock was unhappy running SPD timings of 2.5-4-4-8 @ DDR400 2.6v. Interestingly adjusting the timings manually to 2-2-2-6 @ DDR400 and increasing Vdimm to 2.8v cured this. Indeed, 2.8v is rather high just for DDR400, especially from TCCD. However, HCI Memtest reports no errors, but SPI 32MB test fails. Steps taken thus far: Multiplier & FSB changes, chipset, Vdimm, LDT & Vcore adjustments made. No effect. Varying RAM timing adjustments & switching the modules position, no effect. Applicable DIMM slots tested, functioning. Varying BIOSes tried, no change. Timing adjustments. Current working theory: SPD timings pre-programmed to modules has become damaged somehow, or modules have developed a fault which cannot be picked up by conventional means. System spec: See drop-down tab Next steps: More timing adjustments, moving modules to yellow DIMM slots to varify DIMM slots are not at fault. Current mood: Pissed off. Thus ends the analysis, for now..