Overclocking.

[Pilgrim]

I have an Asus P5P800-VM MB, according to Asus this will take a CPU up to 3.8GHz, it also has an option in the BIOS for overclocking but only by set amounts 5%, 10%, 20%, 30%.
When I run SIW it is showing a maximum CPU speed of 4GHz.
Now I realise that Asus would know more about the MB than SIW but looking at the compatible CPU's that Asus list for this board there are none that go beyond 3.8GHz and I cannot think of any that are between that and 4GHz anyway.

My CPU is a D945 and from new it has been set at +10% giving 3.733GHz, I have tried it at +20% and it will not have it but as that would take it beyond even SIW's suggestion of 4GHz that is not surprising.

The reason that I have started looking at this again is because I recently installed SetFSB on my Samsung NC10 and it has taken it from 1.6GHz to 1.724GHz without any problems with either stability or temperature.
I am wondering if I installed SetFSB on the PC I could increase the speed in smaller increments than the BIOS settings will allow, keeping it below 4GHz.

I realise that one answer is simply to try it and see, which will probably be the outcome, but I would be interested in any comments from people who might have more experience of overclocking.

The D945 is capable of remaining stable at 4.2GHz and beyond with the right cooling, in my case temperature is not an issue as the maximum CPU temperature I have ever seen is 50°C and it usually runs at around 40°C.

[Bearcat]

Just noticed this thread after I posted my own thread about experimenting with overclocking. I don't have any words of wisdom myself Pilgrim, but I am also very interested in seeing if a member with more experience on this topic can help.

[A Guy]

I am not an expert at overclocking, but I can advise against using the motherboard utility that has 5%, 10%, etc. You need to know what it is doing. Is it just increasing the FSB? Changing the multiplier? What about Ram speed, is it making a corresponding change in the Ram ratio?

When the MB says it will support a maximum of 4.0GHz, I'm going to assume this means a 4.0GHz CPU, not overclocking a CPU to 4.0GHz.

If you want to overclock, and correctly, you need to do your research. The CPU and the platform make a huge difference. There are various voltages to consider with the clock changes. Someone like Bear with a new core CPU will have an entirely new method to overclock than I would use on my i5 750.

I have a simple, on demend overclock. I have changed the BCLK from 133MHz stock, to 160MHz. This runs my 1600MHz Ram at it's native speed, and increases the CPU speed, while retaining the speed step/turbo function.

I would always advise against any 1 button overclocks, even if it's written by the MB manufacturer.

A Guy

[Pilgrim]

A Guy,

I cannot comment on voltages because I never checked them before I set the BIOS to +10% although they are still well within recommended limits. In other respects it seems it has increased the CPU clock, the system clock, and the FSB, all by 10% and speed step still works, the multiplier has not been changed. The RAM (4 x VS1GB400C3) is capable of 400MHz according to Corsair so it is running at slightly over 50% of its maximum speed.

The MB is limited to 65nm processors which basically means Celeron, P4 and D series none of which went above 3.8GHz as far as I am aware so I cannot see how you could go the extra 200MHz without overclocking.

SetFSB which I have just used on my Netbook does what it says it increases the FSB, from the many things that I have read it does not change any voltage settings. One question in my mind is whether I can run this on top of the BIOS setting I am using, as everything is well within its capacity and as any software settings do not survive a reboot my personal inclination is that it would but I do not know for certain.

Doing my research was the purpose of my original post, as I was already a member coming here first seemed the obvious thing, if no-one on here has any ideas I will try one of the dedicated overclocking forums.