P55 UD4P Memory Issue (2gb instead of 4gb)

[xAlias]

I setup my old system in a new casing (690 II) and installed a Hyper 212 Plus cooler and new gpu. Everything seemed fine. The next day i thought about tinkering with the CPU clocks and changed the blck to around 140. I also updated the bios to the latest F10.
Strangely, while booting it shows as 2 gb of memory. In bios, it shows as the 4 gb but 2 gb doesnt seem to be enabled.

Reverting the clocks , bios (to F8) etc all doesnt seem to restore the missing memory.

The system doesnt boot with memory in the 2nd slot but the same memory works when put alone in the 1st slot.

I tried also reseating the CPU and cooler as well as the memory.

Any thoughts/help on why this is happening? 🙁


My specs:

Intel I5 750
Gigabyte P55 UD4P (bios F8)
CORSAIR CMD4GX3M2A1600C8 (2X2Gb)
MSI GTX 560

 

[deimos3428]

So previously, both DIMMs worked together but now they only work individually.

Other Thoughts:

1. I would've guessed the new BIOS was the problem too, but you've reverted it already. Did you clear the CMOS afterwards?
2. Did you remove the DIMMs when you installed the cooler? That may have caused one to fail (static discharge). Have you tested both DIMMs individually?
3. Perhaps you are simply reinstalling them in inappropriate slots. The manual suggests that for Dual-Channel operation, the two modules should be installed in slots DDR3_1 and DDR3_3 (white connectors). Some motherboards are more picky about this sort of thing than others; a single DIMM might work fine in any slot.

Other than that, I dont know.

 

[xAlias]

Thanks for replying.

1. I did not clear the CMOS afterwards.
2. Yes, the DIMMs were removed when installing the cooler. Both the DIMMs are working fine i would think as the system boots up to windows when either one of them is installed in the first white connector.
3. No, both are installed in the white memory connectors.