R4E overclocking question

[rsb123]

Hello,
Ive been overclocking my water cooled I7 3930K for the last couple of days and i am seeing some weird situations going on that did not happen to me with my previous board the Rampage II extreme.
I have it to overclock to 4.8 and it post and goes into Windows just fine.
The problem is when i run benchmarking or stability programs (Prime95 or Aida64).
Cpuid sees the CPU voltage at 1.424 at idle and the core speed at 4800 just like it should be, but when i run the applications the voltage drops to 1.392, 1.400. 1.408 and for a while all seems fine and no errors, but the the core speed drops to 3200 (Procesor default). After stopping any of the programs it goes back up to 4800.
I am getting no freezes and no BSOD.
Temps at 100% burn are below 78.
What does this mean?, is it that the overclocking is failing and instead of crashing like my previous board it just reverts to the default speed?
How about the speed?, why does it change?, do I perhaps have and option in bios for energy saving and that's why it shifts?
Also the ram comes with couple of cool fans but i cant installed them since they don't fit with the Gtx680 in place does it matter if I install the video card in another PCIE? or does it always have to be the highest one?
Any help would be appreciated.
All the best

System:
R4E
I7 3930K
Gskill 32Gb F3-17000CL11Q-32GBZLD
Corsair SSD 830 256Gb
Evga GTX 680 Superclocked
Enermax S Galaxy Evo 1250W
Windows 7 X64

[Sonny]

What is your 12V rail at? With a PSU like that, it shouldn't be a problem, but it sounds like you're getting throttled due to either power or heat issues. With the sandybridges you are modifying the turbo clock, so it will only run at turbo if there is a demand for it, and if there is room for it with power/heat. I'd really recommend trying to use offset voltage for your vcore rather then just setting it there, since 1.424v is really high for idling@4.8, and will likely reduce the life of your chip. Also, make sure the the CPU current capability setting is not limiting the power your cpu can receive, for a 4.8 OC I'd say set it to 180% to give you all the room you need.

[Arne Saknussemm]

Hi there!

Are you actively cooling the VRM?....for 4.8 I would advise fixing a good fan over the area....you will probably find the board was throttling you due to heat.

[HiVizMan]

VRM throttling, water cooling does not provide any air movement (cooling) over the VRM area.

Are you selecting a OC profile for the 4.8GHz overclock?

[rsb123]

What is your 12V rail at? With a PSU like that, it shouldn't be a problem, but it sounds like you're getting throttled due to either power or heat issues. With the sandybridges you are modifying the turbo clock, so it will only run at turbo if there is a demand for it, and if there is room for it with power/heat. I'd really recommend trying to use offset voltage for your vcore rather then just setting it there, since 1.424v is really high for idling@4.8, and will likely reduce the life of your chip. Also, make sure the the CPU current capability setting is not limiting the power your cpu can receive, for a 4.8 OC I'd say set it to 180% to give you all the room you need.

Hi Sonny,
The 12V is fine.
I tried the offset option and for some reason the voltage went up to 1.48, so that's not viable.
I went back to 1.4 and added the ram fan ind it seemed to help.
I do keep getting some errors in Prime95 i might need to up the voltage a little bit.
I would like to keep the Ram fans but they don't really fit with the GTX 680 Do you know if I can move it to another slot? According to the manual it need to be on the first.
Thanks again

[rsb123]

Hi there!

Are you actively cooling the VRM?....for 4.8 I would advise fixing a good fan over the area....you will probably find the board was throttling you due to heat.

It seem you are rigth, after adjusting the voltage and adding some Ram fans its better.
The VRM cooling is stock.
Thanks

[rsb123]

VRM throttling, water cooling does not provide any air movement (cooling) over the VRM area.

Are you selecting a OC profile for the 4.8GHz overclock?

You are right also.
Thanks