Overclocking settings for the Asus P6t & Core i7920

[koaladoraemon]

Hi all.
I appreciate all the propmt replies to my earlier posts. Thanks guys.

I'm planning to overclock my corei7920, asus mobo combo. Could anyone supply me with some numbers i.e Bclock, voltages and temps just so that i know what to shoot for. I'm not asking for a guide to overclocking the corei7 920, they're all over the net, i just would like some specs from ppl who have succesfully overclocked their systems.

I heard the absolute max temp for a stable long term oveclock on the i7920 is 85 C. But if thermal management is enabled won't higher temps be taken care of in the sense the cpu will automatically throttle itself down?

Many thanks.

Cheers.

[Matt McDowell]

I'm using precisely the same combination as you!

There are a couple of things to consider when discussing the Core i7 and maximum temperatures. First, the "maximum" temperature you will get depends heavily on how you load the processor. Everest's stress test doesn't get a chip as hot as Linpack. Linpack gets it less hot than Prime95. Finally, Prime95 doesn't get it as hot as Intel's custom burn-in tool. Intel's tool can push a processor with basic aftermarket cooling at stock clocks up to TjMax (which is 100C in the case of the Core i7).

In any case, I personally use Prime95 to check my temperatures. I will push 90C with Hyperthreading enabled (turning it off will reduce your temperatures quite a bit, usually about 10C). Keep in mind though that while my system runs 24 hours a day, I have never seen it exceed 65C under any daily use (usually gaming). Even transcoding doesn't push my processor temps up anywhere near the level that Prime95 does.

From my reading the chip I have is fairly "average", or maybe slighly above average, as an overclocker. I'm going from memory here, but hopefully the names of the various settings will be close to what's in your BIOS. My settings are as follows (Core i7 on an Asus P6T @ 4.00GHz)

AI Overclock: Manual
CPU Ratio Setting: 20
Speedstep: On
Turbo Mode: Off
BCLK: 200MHz
PCIE: 100MHz
DRAM Clock: DDR3-1600MHz

CPU Voltage: 1.35V
CPU PLL Voltage: Auto
QPI/DRAM Core Voltage: Auto (for the record, this SHOULD be called the Uncore Voltage, and not the ridiculous name it has in the P6T Bios. You may need to bump this up a bit to stabilize your system, particularly if you BCLK is over 190MHz. I wouldn't go much past 1.3V though)
IOH, ICH Voltages all on Auto (you might want to bump up the PCIE IOH and ICH voltage a touch if you're running Crossfire or SLI, but I haven't found it to be necessary. I wouldn't go much more than 0.1 or 0.2V over stock)
DRAM Bus Voltage: 1.64V
DRAM REF Voltages: Auto

Load Line Calibration: Enabled
CPU Differential Amplitude: Auto (I messed with this a bit, but didn't get much out of it. I could be stable at slightly lower Vcore, but my temperatures actually got worse)
Spread Spectrums: Disabled
Clock Skews: Disabled

You really should have good aftermarket cooling to push an overclock like 4.0GHz. I feel as though I may be pushing my luck, but since my real-world load temps are well within spec (under 67.5C for 99.9% of use, and 45C at idle) I'm not too concerned. Do check your temps carefully with Prime95 though, just to be sure. For the record I'm using a Corsair H50 with two fans in a push-pull configuration, and Arctic Silver 5. If you're using Arctic Silver or a similar paste, don't forget that they often take ~200 hours to set, during which time your temperature could drop as much as 5C.

Good luck, and have fun :)

[koaladoraemon]

Fantastic!

Thanks a million, And yes, i'm going to have lots of fun.
I can't believe how the prompt the help is here. Many thanks Matt, i'm sure you have loads better things to do than draft a lengthy e-mail. Much appreciated.

[Matt McDowell]

No problem at all. Good luck with the overclock!

[koaladoraemon]

Should I go with the X.M.P Profiles for my Kingston Hyper X 6gb KHdll3gv6x Ram or should i just use the auto settings. X.M.P ups my DRAM voltages to 1.66.
The rule is not that the max DRAM voltage is 1.65v rather its the difference between CPU and DRAM voltage should not be more than 0.5v yes?

I have a Xigmatek Thor's Hammer mated with two 2300rpm 38mm fans, they're a little noisy, but idle temps are about 41-43C idle, ambient temps 29C. I live in the tropics.:)

[Matt McDowell]

It's actually the difference between the RAM and the Uncore Voltage (what the P6T calls the QPI/DRAM Core Voltage) that needs to be kept within 0.5V. This limitation doesn't apply to the CPU Voltage though.

If you are going to run your RAM at 2000MHz (that's a great RAM kit, by the way), I would highly recommend that you stick with your DRAM voltage at 1.66V. Go with the stock timings. Your kit can do 8-8-8-30 at 2000MHz, which is pretty amazing all by itself. There's little need to push your RAM harder than stock settings.

With this is mind, the default value for the QPI/DRAM Core Voltage is going to be within that 0.5V window. In other words, make sure your DRAM Frequency is set to 2000MHz, set the voltage at 1.66V, ignore X.M.P. and call it a day.

That's what I'd do anyway :)

[koaladoraemon]

Will do!
thanks Matt

[koaladoraemon]

It's actually a Kingston 6gb 1600mHz HyperX Kit. 3 pcs of 2gb each- Total 6gb.

Model: KHX1280D3LK36GX

How far can i push this baby? Will it go to 2000Mhz too?

Thanks

[Servando Silva]

Is your RAM the cas8 or cas9 kit?
Also, is it the tall heatsink kit or the normal heatsink?

I don´t really recommend using XMP on the RAM unless you have your system @ stock (except for the RAM of course). XMP uses high QPI voltages which are not really neccesary and if neccesary, it will also OC your CPU to match the BCLK with your RAM freq.
Manual settings are normally the best option.

Now that I saw you have a good cooler in action, I must remember you in case you really want to push your RAM to 2000MHz or similar and not the lousiest timings you will need to bump your Uncore Voltage (QPI/DRAM for ASUS). Probably 1.3v won´t be enough for it. Try not going over than 1.5v and max 1.6v. I think you will need around 1.45v-1.5v for using 8-8-8 or better latencies. BUt this all ends to asking which kit do you have, the tall heatsink with cas8 or the normal heatsink memories since the IC may change on this and the voltage/clocks scaling.