cp wrote:just for starters: find out what PFC is for and what it has to do with efficiency. sum up the wattage of the different voltage rails (assuming they are independend of each other) and compare it with 420W.
What PFC does is keep current and voltage in phase, lowering the stress on the power grid. I didn't have to look that up btw. IMO it is only important when you are drawing close to the limits of the breaker on your circuit, a power supply with PFC is less likely to trip the breaker than one without. Otherwise... CCFL bulbs are among the worst offenders when it comes to injecting harmonics and noise in the power line, but tell me, you ever seen PFC in one of those? Of course not, because they have to be as cheap as possible (and they're more expensive than the regular incandescents anyway). Oh yeah and they're banning incandescents... I'd rather run a good ol' fluorescent tube rather than a CCFL bulb, at least a regular fluorescent tube actually gives usable light. Perhaps LED lighting will go down in price before all incandescents are banned, anyway, enough off topic.
cp wrote:yes, possible (possibility for just those 2 pins out of 370 pins..you can do the math). there are more than enough pins (data, address, ...) that are way more sensitive to improper connection than those VID pins.
You don't know how many things with <5% probability have happened to me. I don't have to do math for that. But regardless, we are talking of a board that wasn't designed for those CPUs in the first place, AND after the VID mod everything is fine.
cp wrote:get a PSU that is at least 80plus certified and delivers at least 20A on the +5V rail (i'd get a Seasonic SS-400ET or Seasonic SS-350ET, both available for 30-40€ each)
I bet i could put in this system the Seasonic SS-500HT that i have in my Core 2 Duo at home, and it won't run it
. I already mentioned before that my Xilence has 27A on the 5v rail and it isn't enough. It's not about the rail capability per se, you forgot to think about crossloading.
Since all rails are derived from the same transformer (well except the 3.3 which is regulated by a magamp, but it's regulated from the 5v rail so it still loads that up), the power supply is designed to be loaded with somewhat equal amounts of power on each rail, to stay in spec. Since my system consumes next to nothing on 12v, the 5v rail sags. If enough feedback were applied to keep 5v in check in this situation, 12v would probably go so high that it would blow something up. I've seen it at 12.8v on the old motherboard, this one seems to be a bit more 12v hungry and it stabilizes around 12.5v.
This is only avoidable in the new designs based on DC-DC converters, where there is basically one fat 12v rail and everything else is down-regulated with buck converters. Unfortunately those power supplies tend to be expensive, and i have yet to see one with more than 20A on the 5v rail, they're all 12v oriented for modern hardware. But in essence, this is what i'll be doing, just that the buck converter i will build is intended to supplement the 5v rail coming directly from the transformer, not replacing it entirely.