Two kind-of-connected questions in one here (sorry, I'm lazy ).
1. Most CPU reviews/guides look at overclocking with respect to the stock voltage. However, do definitive values exist for a given CPU, or is this stock really specific to the mobo (and it's this that people report on in reviews)?
Having a look through all AMD's official tech sheets (for a Phenom II X3 720BE in my case), they only seem to give the voltage range: the "AMD Family 10h Desktop Processor Power and Thermal Data Sheet" gives 1.15 - 1.425V for P0 at 2800MHz.
I have understood that mobo manufacturers sometimes set the VCore high (for guaranteed stability, presumably) e.g. Asus: on my M3N78 Pro, it's reported as 1.4V in the BIOS, though reviews of this CPU suggest it's supposed to be 1.325V.
So do definitive values exist and where are they officially listed if so??
2. On this note, I've been using Phenom MSR Tweaker (PMT from now on...) since, on my board, CnQ turns off if I overclock the FSB (but, strangely, only on Win7 and not Vista). CPU-Z (and Asus PC Probe II) both match in giving a voltage of around 1.4V in the P0 state, yet I need to set the V in PMT at 1.325V to get CPU-Z to show this c. 1.4V voltage.
Any ideas why this is? My guess is that 1.325V is the official stock (still don't know how I find this out though!), which PMT sets via some given Windows BIOSy interface, and the Asus BIOS applies its own adjustment to this, as it does in the vanilla state. Just a guess but is this likely? I know that CPU-Z / HWMonitor can sometimes report wrong voltages depending on the monitoring chip, but the 1.4V matches what the BIOS HW Monitor says (from which, I also presume that it boots into the P0 state).
Sorry, ended up longer than I intended but any advice/info. appreciated.
Cheers.
1. Most CPU reviews/guides look at overclocking with respect to the stock voltage. However, do definitive values exist for a given CPU, or is this stock really specific to the mobo (and it's this that people report on in reviews)?
Having a look through all AMD's official tech sheets (for a Phenom II X3 720BE in my case), they only seem to give the voltage range: the "AMD Family 10h Desktop Processor Power and Thermal Data Sheet" gives 1.15 - 1.425V for P0 at 2800MHz.
I have understood that mobo manufacturers sometimes set the VCore high (for guaranteed stability, presumably) e.g. Asus: on my M3N78 Pro, it's reported as 1.4V in the BIOS, though reviews of this CPU suggest it's supposed to be 1.325V.
So do definitive values exist and where are they officially listed if so??
2. On this note, I've been using Phenom MSR Tweaker (PMT from now on...) since, on my board, CnQ turns off if I overclock the FSB (but, strangely, only on Win7 and not Vista). CPU-Z (and Asus PC Probe II) both match in giving a voltage of around 1.4V in the P0 state, yet I need to set the V in PMT at 1.325V to get CPU-Z to show this c. 1.4V voltage.
Any ideas why this is? My guess is that 1.325V is the official stock (still don't know how I find this out though!), which PMT sets via some given Windows BIOSy interface, and the Asus BIOS applies its own adjustment to this, as it does in the vanilla state. Just a guess but is this likely? I know that CPU-Z / HWMonitor can sometimes report wrong voltages depending on the monitoring chip, but the 1.4V matches what the BIOS HW Monitor says (from which, I also presume that it boots into the P0 state).
Sorry, ended up longer than I intended but any advice/info. appreciated.
Cheers.