Sorry to necro but thread has useful context.
Do any of you still use a vishera in the m4a89(g)td pro/usb3?
I ask because I just set one up. I am noticing that the default vid for cpu-nb for Vishera in these boards is 1.55V, which is very high.
Have anyone found out anything about this? Is this number real or just the motherboard not understanding something. Since I can't undervolt it very far (1.45V maybe) I'm thinking this can't be the real value.
There are some threads on overclock.net about this where people report the exact same behavior I'm seeing but no one can explain what's happening.
I will be installing AMD overdrive later since that reports the cpu-nb vid value in windows I think. Does any other program? HWMonitor does not.
Also, I may have discovered a way to defeat the throttling. I don't think the throttling is VRM-heat related in my case because the VRM heatsink is only warm to the touch and I'm throttling on a 6-core even at 3.8ghz for two cores loaded only!
The throttling always drops the multi down to 15x, so by using fsb overclocking with a 15x multiplier, 300x15 = 4.5ghz. This could completely prevent throttling below 4.5ghz. However, the drop to 15x is accompanied by a relative drop in max Vcore, too (~.8V). Right now I see no way to prevent this so I would need a bit of headroom in Vcore to make up for it.
As a compromise I was thinking to do 275x15 = 4125ghz, then pick a higher multiplier to get >4.5ghz. Then I have sort of a custom turbo that will only throttle to 4125ghz under heavier loads. The problem I am having is I seem to have hit a FSB wall at around 248mhz. I know the board can do more, and I see people getting 250mhz FSB with vishera in other places, maybe this chip is unlucky?
(This is a lot of effort to save a little money but there's some fun involved, too)