Overclocking Q9550 and a couple of questions…

[Arturas]

Hello everyone!!

This week I started looking into overclocking, something that had never even crossed my mind before, and as you can imagine, I have a lot of doubts.

My equipment is as follows:

Motherboard: ASUS P5QL-E
CPU: INTEL Q9550 (2.83GHz)
RAM: Kingston DDR2 1066

I've been tweaking the settings and left it as follows:

FSB: 400 (x8.5) = 3.4GHz
RAM: 1066
PCI: 100
Voltage set to AUTO (BIOS gives me 1.32v)
RAM Voltage: 2.20v

The computer is completely stable with numerous tests for a long time, with temperatures below 60°C (liquid cooling).

My main doubts are about the FSB and the RAM.

I can't increase the FSB any more, since the motherboard's specifications say that the maximum FSB in OC is 1600 (exactly the one I have now) and I get an error when booting if I go above 400, so... do I deduce that I can't increase the processor's speed any more? Does the motherboard set the limit for OC and not the processor itself? How is it then possible that some people with this processor can take it up to 3.9 or 4.0 GHz?

And regarding the RAM... I have it at 1066 which is the maximum that the modules allow, but I've heard that it's better to have it at 1:1 (right now it's at 3:5 or something like that according to CPU-Z)... should I change anything about it? Should I leave it at the maximum they can get or would it work better if I lowered it? Is the voltage of 2.2 okay or is it high?

Thank you very much for your help and for your time... let's see if I can squeeze out a few more MHz ;o)

Best regards,

Arturas.

[Fassou]

Check out these posts:

Basic OverClock Guide Q6600 - HardLimit

Overclock Guide Intel C2d E8400 - HardLimit

Salu2!

[Arturas]

Hello, thank you very much.

I have read it and I more or less understand it, but I don't know how to solve my problem since I have the multiplier at the maximum possible (8.5) and therefore, to exceed the 3.4GHz that I have now, I should touch the FSB that is already at the maximum of the board...

Well, I'm all confused...

Thank you very much.

[krampak]

The FSB is not at the maximum of the motherboard, if anything it is at the theoretical maximum (for what it is designed for) but you can overclock. You should be able to increase it more, doesn't the BIOS let you do it?

If it doesn't boot up, it might be because by increasing the FSB you are also increasing the speed of the memory and you would have to play with a divider to reduce the speed of the memory as you increase the FSB, that or relax latencies or increase voltages, there can be several things but what is clear is that with a processor without an unlocked multiplier you can only increase by means of the motherboard bus.

Anyway, if you have already increased it from 2.83 to 3.4 it is not bad at all, from there you may need more voltage and better refrigeration. That there are people who have increased it to 3.9 or 4Ghz means nothing since you don't know with what motherboard/chip/refrigeration/voltages they have achieved it.

I would almost bet that you are missing CPU voltage and that probably from 3.4Ghz it will start to ask for quite a lot of voltage (it always depends on the luck you have with the chip).

Edit:

1.2-1.3V - for a FSB of ~400 MHz.
1.4-1.5V – for a FSB of ~420-440 MHz (exceed 1.4V at your own risk with a 45nm chip)!
1.6V – for a FSB of ~440-475 MHz - use at your own risk with a 45nm chip!

You should be aware that newer 45nm fab chips are MUCH less tolerant toward high VTT than their 65nm predecessors. Anantech published their experience frying a QX9650 with high VTT’s as an example.

Vcc – Initially, set within 200-400 mV of where the auto setting used (remember that you need a little more in the BIOS compared to what CPU-Z told you). Remember to consult Intel’s processor finder to know where the upper-end of safety is for your processor (I believe the figures there correspond to the values CPU-Z is displaying, not what you set in the BIOS.).

DRAM – What ever the RAM manufacture recommends is a good starting point. Unless you’re really overdriving them, they shouldn’t need more.

SBCore – I’ve always used the lowest setting, but I typically don’t push my systems that hard (20-25 %). You’re on your own here.

NBCore – Start off low, 1.33 or 1.37 and see if you need more. Also, a little bit can go a long way. My system is unstable @ 1.330V here but stable @ 1.370V which is a difference of only 40 mV (0.04V).