4930K/X79A-GD45 - acting weird

[Woomack]

As some already know I've got 4930K and MSI X79A-GD45 Plus some days ago.
Yesterday I was trying to check stability with higher clocked memory and this is what I found:
- strap x1.00/100bclk + 2666 memory = no boot at all , 2400 100% stable on stock voltages
- strap x1.25/125bclk + 2666 memory = benchable but is crashing from time to time and have errors in memtest at about 65%, no difference at high or low VCCIO/SA or memory timings/voltage, 2333 100% stable ( there is no 2400 to choose )
- strap x1.67/167bclk + 2666 memory = the same as x1.25 strap , 2220 100% stable ( there is 2220 or 2666 or higher )

The same memory is running 100% stable on the GB Z87X-OC board @2666+ and the same I wish to achieve on X79 ( well I wish higher but this will be good enough for now )
Probably it's mobo issue but I'm not sure if I haven't missed anything so maybe anyone has any idea what can it be ?

 

[ninjacore]

I'm assuming your CPU is overclocked as well? I haven't OC'ed my Haswell yet, but I read our frontpage's Haswell OC guide and remember it mentioning CPU overclocks causing memory overclocks to be less consistent or, at least, flakier.

 

[Kaspa]

Sounds like IMC issues to me. Here's a thread to browse.

 

[Woomack]

No difference if CPU is overclocked or not. Strap x1.00 isn't working with memory at 2666. What is weird , 125MHz or 167MHz bclk is usually much harder to achieve but at these two higher straps it's working pretty good ( maybe not stable but is passing harder benchmarks ). I was able to make ~2750 memory clock for some quick benchmarks with 32GB RAM.

Thanks for the link , will check it later.

 

[Woomack]

Little update, I made it work stable @2666 but at higher strap, with 12-14-14 timings ( while on Z87 it was stable at 11-13-13 ) and 1.34V VCCSA what is quite big bump from nearly stock voltages at 2400.
MSI support said there is no new BIOS or any newer beta than we can find on their download page. They also can't guarantee any settings above 2400 so they can't help me ( standard answer ).
At least I can bench @2700 .. will fight some more and report later if I fix that low strap/higher memory issue

 

[MetalRacer]

Have you tried leaving the strap setting on auto and just raising the BCLK?

 

[Woomack]

I don't remember ... will check when I back home.

Edit:
It's acting the same on auto settings.