1. Safe maximum temperature and vcore? - there is loads of rubbish on the internet and I don't seem to be able to find a decent answer so far
Heh I agree with the load of rubbish bit!
I would say you don't have to worry about the safety bit or maximum vCore as the thing that will hold you back is the temps . . . . once you reach a certain speed using
mortal cooling you will hit a brick wall due to the temps, can't say for certain if this is a CPU/IMC situation or perhaps something to do with the MOSFETS but the Athlon X2's really don't clock well past *roughly* 65°C
2. The vcore does not match (exactly) what I specified in the BIOS and it does not stay stable as reported by CPU-Z, it varies from 1.488 to 1.504 V and even more at the next highest increment. Is this ok?
Well that's perfectly normal although as an overclocker I can't say any of it is desirable!
The difference between what you set it BIOS and the resulting vCore as displayed under CPU-z is refered to as
vDrop. Basically ignore what you set in BIOS and use the reading in CPU-z as your target. If you have to set 1.60vCore in BIOS to attain 1.45vCore under CPU-z then consider the chip as being fed by 1.45vCore and forget the 1.60VCore reference other than thats what you need to set in order to attain 1.45v!
Once you take the chip from Idle and Load it up with a diagnostic you may see the voltage displayed drop lower,again this is normal on older system as is refered too as
vDroop.
Ideally an overclocker would want to set a certain value in BIOS and have that value applied to the hardware but it doesn't wuite work like this, at least on all the hardware I have used myself the past 15 years! . . . you can get around vDrop by using CPU-z as your vCore readout, you can kinda get around vDroop by bumping the voltage high enough so that at its lowest Droop there is still enough juice to keep the loaded processor stable.
On more modern systems there is a feature called
Loadline Callibration which does a great job at negating vDroop. Another thing that *may* be worth looking into is the cooling on the motherboards PWM's, these take the course power from the PSU and convert it into finer CPU ready power, if the PWM's start overheating beyond a certain point I think they struggle a bit at delivering the clean ripple free power i.e if you have well cooled PWM's the vCore line should hold fairly steady once the chip is under load.
The only other thing to mention is always make the distinction between the vCore you set in BIOS and the vCore reading you see in CPU-z when communicating with others through the Interweb, vCore-BIOS, vCore-Actual etc as I think this will be more useful to others!
3. What to do with the Ram speed when the 'dividers' are so wildly far apart, for my current settings it is either 182.3 or 232 MHz, so which to aim for?
The fastest possible setting that also is fairly hassle free, YMMV but if in doubt try them both out yourself and see if you can notice the difference, if you can't notice the difference in the real world then you can always use some benchmarking software to see if anything is happening!
Of course give the RAM full respects and make sure it is well cooled and running with reasonable voltage as baking hot/over-volted sticks tend to die!
4. What is the max speed I should aim for?!
Well that depends, one normally tries to find the max possible fully stable MHz, some others don't really care for stability and will aim for the max MHz that can complete a benchmark or in extreme cases stable enough to validate CPU-z before the machine BSODS . . . .personally I am only interested in fully stable overclocking so I will spend a fair bit of time trying to get the speed as high as possible while at the same time being able to complete lengthly Prime95 testing and long gaming sessions.
In your case with the Athlon 64 X2 4400 I would be aiming for about 2.5GHz-2.6GHz although if you have a rare chip and great cooling you could get up to 2.8GHz running stable! . . . . having said that once you get all your testing and benching out the way you may decide on a slightly less ambitious speed for day to day useage . . . the higher the voltage you chip needs to reach higher speeds means the higher its energy usage, this may not be a real problem if your machine is running a few hours each week but if its 24/7 then you can't ignore the increase running costs £££ pumping the vCore brings . . .so with that in mind you have to work out what is your personal sweetspot!
Hope some of this has been helpful and buy yourself a headtorch for the next time you have to build in the dark!
