AMD A10-7850K RAM related question(s)

[Broadbanned]

Hello my fellow hardware lovers,
I recently built a fun box with an AMD Kaveri APU, and I've run into a little trouble with stock 2133Mhz. RAM settings. I'll post the specs and manufacturer links below, but basically using the serial presence detect (SPD) values for 2133Mhz. or even 1866Mhz. yields instability and consistent bluescreens relative to memory problems and HDD data corruption. Also, memtest86 always fails (endless errors) on Test #7 [Block Move]. As I understand it, the A10-7850K comes with a stock northbridge frequency of 1800Mhz. (18x 100) which isn't a matching frequency for either 1866 much less 2133, so I can understand why the block move fails. I have tried overclocking the northbridge to 1900 with 1866Mhz. RAM setting, and also pushing the northbridge all the way up to 2100 since it won't post at 2200 regardless of northbridge voltage setting, but the block move test fails and I can't get stability in any situation unless I set the RAM to 1600Mhz. at which point everything is stable. As a troubleshooting step I used another set of 2400Mhz. rated G.Skill RAM from another computer to verify it wasn't that I was using some bad sticks. Any suggestions would be very much appreciated, even if I have to RMA the APU I'd like to hear what you all think

APU: AMD A107850K stock settings. http://

Heatsink: Coolermaster Hyper 212 Evo (idle 29C, Prime95 load 35C)

Motherboard: ASRock FM2A88X+ Killer Fata1ity http://

RAM: G.Skill TridentX DDR3 2400Mhz. http://

 

[mlga91]

What voltage have you set for the memory? if its at default 1.5 that could be your problem.

 

[Broadbanned]

I use ASRock's XMP support to set all RAM related settings, but I've also tried manually setting them. But yes, each time I verify it's set to 1.65 for 2133Mhz. setting. I've also tried increasing the voltage to 1.7 to see if it would stabilize, but no matter what I change, I get the block move fails in memtest86 and eventual blue screen in Windows 7 / Windows 8, and a Kernel Panic in my Linux distros.

Edit: Kernel Panic accompanied by MCE logged in Linux indicating RAM data copy errors in both DIMMs.

 

[Broadbanned]

DIMM placement was the cause. I switched the pair from the slots closest to the APU socket to those furthest away and it runs at 2400MHz. stable, default 1.65v and XMP profile loaded.