VCore Voltage Offset

[Taz]

I've been reading through my motherboard manual and will be playing around with the BIOS over the weekend. I have noticed a couple of BIOS options that i'm unsure of. I've searched around on various forums and the Internet but still haven't found a clear answer, although I think I understand them but just need my undertsanding confirmed.

I'm referring to the voltage settings for an A64 3500+ Winchester and an A8V-E Deluxe (VIA K8T890 chipset) motherboard. I understand that this CPU needs a stock voltage of 1.4V.

There is a parameter called 'Hammer Vid Control' which is set to 'Startup'. This can be changed to numerous other voltages (well below 1V to around 1.8V at a verz fine level of granularity). I'm guessing that the default value of 'Hammer Vid Control' set to 'Startup' means that the BIOS will interrogate the CPU and obtain its stock voltage at system startup (1.4V I assume) and set the VCore to 1.4V. Is my assumption correct?

However, there is also another prameter on the same BIOS screen called VCore Voltage Offeset that has two possible settings: +100mV (default) and +200mV. This is what confuses me. Is this voltage being added to the 'Hammer Vid Control' to get a final VCore voltage?

If this is the case then would I need to set Hammer Vid Control to 1.3V to get the final stock value of 1.4V (assuming VCore Voltage Offset is set to +100mV) if I wanted to manually control the VCore voltage?

[Steve]

Just had a wee scoot about on google and it looks like the offset feature just ups the voltage by that amount, and vid control is for specifying the voltage you want.

edit: Oh hang on, it might be how much you increment the voltage by each time. Oh I dont' know now - shame it's not in Rojak Pot's BIOS Guide yet.

[Kumagoro]

from an electronics point of view it sounds like the starting value of voltage so if its
not reaching what it should you can stick an extra 100 mV through it etc.

In the setting do you have to have 100 or 200 mV or is there an off setting like 0 V?
if there isnt it seems strange you have to have a compulsory offset.

[Taz]

No, there's no VCore offset of 0V! Just +100mV or +200mV. I think this value is added to Hammer Vid Control if the latter is not set to Startup! I've searched everywhere and the Asus manual is absolute pants so of no use whatsoever.

Anyway, i'll be playing around with this feature over the weekend so will post info on here as hoping it might help someone out!

[Kumagoro]

http://forums.silentpcreview.com/viewtopic.php?p=136239

someone says that its apparently for mobiles, not much on it at all is there.

[Taz]

Yeah, I did see that article. The range of voltages is astonishing - you can undervolt the CPU (i.e. mobile CPU's). The range goes from 0.800V to 1.5625V in increments of 0.0125V (12.5mV). I'm guessing that the CPU VCore Offset (+100mV or +200mV is then added to the manually set voltage to set the true VCore.

I've also seen an FAQ on the Asus site for my mobo and, apparently, the Hammer Vid Control, Memory Voltage Adjustment and CPU VCore Offset BIOS settings form the feature called 'Precision Tweaker' that Asus are marketing for the mobo's at the moment. It's a shame they don't explain how to use it!

I'll be sending Asus and e-mail for some clarification but i'm pretty sure it's what I originally thought. If I play around with it at the 1.4V level it probably won't do much harm!

[Edit]: Found this on the Asus FAQ site:

Q: I found a new overclocking feature "Precision Tweaker" on ASUS A8V-E Deluxe user manual. What is special about it?

A: Precision Tweaker technology is designed for overclocking users. This feature allows you to increase CPU and memory voltage gradually in order to achieve maximum system performance. If you wish to increase the CPU voltage, please go to BIOS→Advanced→JumperFree Configuration→Overclock Profile, and set the selection to "manual". Then, you will find "Hammer Vid control" selection for adjusting the CPU voltage and Memory voltage in "Memory Voltage Adjustment" selection on the same page.