Hi all, I am in need of some help from the masters.

I am far from an expert overclocker, just a dabbler. Was hoping you could share some advice on a strange situation I am having. Here is my setup:

3930K
Rampage IV Extreme
16GB (4x4GB) Gskill DDR3-1600 F3-12800CL9Q-16GBZL
Silverstone ST-1500 PSU
GTX 480 Tri-SLI

I have the two extra PCIE 6 PIN & ATX CPU 4PIN connectors also hooked up to my PSU.

Currently I am running 46x100 = 4.6GhZ @ 1.36V, using High LLC and the other voltages I have set manually are 1.175 for CPU VTT and 1.175 VCC, PLL 1.95 and DRAM 1.65. All C1E/Speedstep etc. is off. I am using a NH-D14 CPU cooler. Load temperature is about 65 on all cores.

So I decided I'd like to go for a higher clockspeed since I am okay with up to 1.40 to 1.42V or so (yes I am a wimp) I discovered this funny situation while I was playing with my overclocking.

To test stability of my 4.6 overclock I ran Memtest 86+ for 8 hours - no errors, HCI memtest to 1000% coverage - no errors, 20 passes of LinX with Max memory - no errors, 24 hours of Prime95 Small FFTS - no errors, Prime Blend 2 hours - no errors. I also can play any game, BF3 etc and have never had any freeze-ups, BSOD or crashing.

I thought the 4.6 overclock was just fine. So when I was playing with my new overclocks at 4.7 and 4.8, again I could pass 20 passes of LinX and run a little prime95 small ffts fine (just a few hours before I found this problem) I decided to try doing Prime Large FFTS instead of blend, system BSOD error 101 after 5 minutes. I tried to give it more voltage all the way up to 1.41V for 100x47, still BSOD in Prime Large FFTS. Also tried raising VTT/VCC to 1.2, no help.

So I went back to my original 4.6GhZ overclock. I was curious and tried to run Prime Large FFTS on the 4.6 overclock.... BSOD after 5 mins, error 101!!!! I couldn't believe it, the system was totally stable and passed linx, prime small, prime blend, memtest 86, HCI memtest - but it fails prime large ffts. I've tried giving it lots more voltage to Vcore, VCC, VTT, memory, playing with higher LLC and still crashes after 5 mins of Prime large ffs with BSOD 101. But the system is totally stable in everything else.

Any advice from the experts why this test is failing for me ? And otherwise system is rock stable in all other tests ? (but obviously not stable since fail prime large ffts!!)

Thank you in advance.