x79 DDR3 OC. CPU Strap can up your clocking easy.

I was wondering why there aren't more writting about this..

but using CPU strap at 125% and (and adjusting bclock there on)

I found the x79 board actually quite eagerly OC the memory higher.

did a series of test last night, and easily reached 2400Mhz with some much cheaper RAM (rated for 1866/2000/2133 respectively), of course, the 2133 resulted in a much tighter timing than the 1866 at 2400Mhz.

anyone tried to get 2666mhz off these RAMs yet? would like to know results before I wander into the unknown.

cheers.

I've seen quite a few people talk about that, but it's buried in forum posts about benchmarking. You have a strong IMC to reach 2400+. My 3960X chip won't even get to 2400; its highest is ~2300. I doubt many SNB-E chips will make it to 2666, but it might be fun to try if your sticks are capable. The timings are what hurt when benchmarking though. 2200-2400 with tighter timings is generally the sweet spot.

thanks for answering, I need a RAM expert here. hehe.

I have been using CPU strap to do the trick, and yeah, need to change the CPU multipliers, and ended up getting 5015Mhz instead of my 5.0Ghz. at 125 strap, the 2133 kit was the easiest to clock, actually able to keep it's own timing so far.. (cause 2400/1.25 is actually just 1920.. way below the stick's own rated Hz.) It has passed Prime95 for 2 hrs. (I call that good), and SuperPi32M returned my best score so far. (which probably still not helping the benching team too much...)

but I am happy.. CPU same Vcore 1.52V, Vdimm at 1.7V. =)

current bios
CPU strap 125
bclock 128.625 (so real base clock at 128.625/125 = 102.9)
Vcore 1.52
CPU multipliers at 39-39-39-38-38-38 (need LLC at HIGH instead of Medium though.. else just not enough voltage during transits)

DDR3 2400 9-11-11-27-1 (4-128-9-4-24-4-6-8) (so sad.. I can remember that by heart now.. sigh)
Teritary I just had it on Auto..
Vdimm 1.7V

Rampege tweak is on Mode2, the one for overclocking.
Had to get manual a lot of settings in DIGI+ just to get pass the power requirement...


... the tuning of this set of RAM took me 4 hours.. and I am a little gun shy about going the next notch up... I stumbled onto something stable now.. feel a little sad about unsettling it again...

so I guess what I am saying is..
Does anyone want to convince me to go higher? or should I be happy with 2400 now?

is my BIOS setting ok? any feedback will be UTMOST appreciated.

2200-2400 with tighter timings is generally the sweet spot.

Click to expand...

or maybe that's what I want to hear. hahah, thanks, now i can sleep well tonight.

I'd be wary of running over 1.65V on the RAM 24/7. 1.7 is fine for benching temporarily but you don't want to stress the RAM controller for so little gain for general computing. Stress it when you're benching, but IMHO, back off for 24/7 use.

I wouldn't worry about trying to go higher speed either. Drop down a notch and start playing with timings. You may find you're faster with slower speed, but tighter timings. If you want to tweak, start messing around with sub-timings. There is a tenth of a second here and there to be gained by proper sub-timing tweaking.

thanks and noted.
1.7V was my test voltage, as I want to be sure it is receiving enough.
I just tried to dial down the voltage a little.. after a few tries, at 1.68V I am still passing all tests.. with my 1.65v, sometimes the offset triggers up to 1.68v anyway.... so I will hope 1.68v should 'not too bad' for a 24/7 system?

(my old kingston hyperX always ran at 1.65v then too.)

If you are running a C2 chip I wouldn't even try running 2666mhz.

The fun thing about the C2 chips is that the IMC is nice and weak so when you raise the VTT voltage it kills the chip. Sticking with 2400 or so is your best bet even for benching.

I will take our experts advice.

I really doubt running ram at 1.68 24/7 will hurt anything.

I mean the chip might not last 10 years, but it doesn't need to anyways right?

Nice work on that OC =) You should write a guide or something. That is some impressive work you did there.

is it? thank you, I am a little shy about it, but I am quite happy about my machine's performance too. very stable.

I still have much to learn though..