Seasonic psu somehow limiting vdimm?!?!

[Ewok]

I got a Seasonic S12 600w to replace my extremely noisy PCP&C 510Turbocool, only to find a massive difference in overclock.

This turns out to be because the volt mod (POT) on my P4C800-E Deluxe, is now refusing to get a voltage above 3.24v regardless of where I set the pot. It's also dropping to 3.11-3.16 under load. It WAS set on 3.31v with the PCP&C.

Surely the psu cant be limiting this, but it was working find with the other less powerful psu. And surely the mb cant be limiting it because again, it was fine with the other psu.

The rails on this are also not good at 11.79, 4.83 and 3.18 in asusprobe and bios at idle (although they do not fluctuate at all under load so load is not a problem it has obviously just been badly calibrated or something). However I've never had even a 1ms overclock difference from rails that were a bit low, providing they didnt drop under load due to lack of power, and these do not drop under load. I do not believe the bad rails are a factor at all.

I only have 1dvdrw, 1 ati x800 pro (not modded) and an sblive, so its hardly a heavily loaded system even!

Any ideas what/how/why is limiting the bluddy vdimm to 3.24 and if I can fix it? otherwise ive spend £100 on a useless psuthat has plenty of power, is nice and quiet, and cant overclock.

[Aleman]

why the hell did u replace that P&C????

[Ewok]

I got a Seasonic S12 600w to replace my extremely noisy PCP&C 510Turbocool
...

http://www.auphanonline.com/articles/view.php?article_id=1487&page=2

according to that page, theres no overvoltage protection on the P4C800-E Deluxe that would stop me doing this (im not using an oc booster but the same information applies to using a POT) so it has to be the psu.

[Highland3r]

Vdimm feed on the P4C is off the 3.3v line, so the absolute MAXIMUM the vdimm can be is whatever the 3.3v line is running at. Usually its ~ 0.1-0.2 below this as other things also use the 3.3v line for power.
The DDR booster runs off a 5v supply, so in theory the max you can run is 5v (though this is limted by the booster itself)

I'm struggling to understand firstly why you replaced the PCP&C and secondly what your issue with vdimm is... I'm assuming you left the PCP&C pots at stock, so baring the droop on the rails, you should have a similar amount of Vdimm available. If you adjusted the pots on the PCP&C and moved to a stock PSU, well go figure....

[Ewok]

the PCP&C was driving me mad with the noise it makes so i wanted a quality psu that didnt make a noise and from my research seasonic are about the best.

the pots on the PCP&C were not at stock, i adjusted them slightly higher and i believe the 3.3 was at 3.4.

if this is indeed the explanation then ill be stuck with it as theres no way im paying £35 x2 for boosters to get me more vdimm off the 5v line.

[Highland3r]

Thats the issue then. You either need to increase the rails on the seasonic or get a DDR booster.

How come you are needing 2 btw?

[AKURA]

You could've just bought a panaflo ultra fan and replaced the delta that was in there for silent operation. While still keeping the same air circulation needed for the PcP&C. That was a bad move still. You traded a ferrari for a riced up civic :D

You can probably do a 3.3V sense line mod for that S12 600W if it has it on the 24pin EPS connector. :)

[Ewok]

i would need 2 boosters for 2 sticks of memory right?

i could have tried another fan, but ive found panaflos no better than any other fans and its still an 80mm fan thats gonna make noise when it gets faster. this seasonic has a 120 and i cant even hear it.

3.3v sense line mod? highly unlikely i would be able to do that

[SlackeR]

No, one booste boosts all slots on the mobo.

Sense mod is easy. Cut two wires and connect at pot and you're flying ;)

[Ewok]

i really dont want that booster rubbish so i may have no choice but to get a new fan for the PCP&C and hope it manages to create silence out of it.

one thing i dont understand is how some boards come with bios that allows more than 3.3v right out of the box, if so, how? no psu will be able to provide that unless its got variable pots on it like my PCP&C to change the voltages (and most dont), but ive never heard that mentioned before.

[Dave in Daytona]

Well they could use the +5V for Vdimm. :slap: