Asus P5N32E-SLi Mosfets

JabbaTheHutt · #1 09-03-2008, 22:09

Anyone here care to give their experiences of water cooling the Mosfets on the Asus P5N32E-SLi (nVidia 680i chipset).

just as a little background I run Prime95 on two cores of an E6600 dual core on the Asus P5N32E board, the board is in an Antek 900 case in a dedicated PC cabinet with doors that can be closed but the rear of which is 30% open (where the back of the PC sticks out). Right now I can't close the doors because it gets too hot (CPU runs at 50°C) and frankly the fans are too damn noisy by a long way.

I had this board water cooled once before and I ended up with a fan anyhow because of the Mosfets getting too hot so I ditched the water cooling just because of the damn mosfets (this was before water cooling blocks for Mosfets on this board were available).

In the current location even a fan for the Mosfets isn't going to work - it will only recirc hot air, ventilating the cabinet ain't gonna fly, too noisy (tried it), and too untidy for a cabinet trying to look innocent in a dining room, I need to remove as much heat from the cabinet as quietly as possible and water seems to be the only option.

The plan is to add a 240 or 360mm radiator Black ICE-Xtreme III ??), 3 quiet fans (Noctua NF-S12 ??) and an XSPC 250mm Passive but I need help with some stuff ...

Questions.

1 : How many mosfet blocks are needed and which ones - I think the Asus 1 (EK-M-1) from EK or the MIPS MCH133, but how many - 1? or 2? - when you buy these things and add to a basket the quantity shown is 1, but is this 1 box with 2 cooling blocks or 1 cooling block, if it is only 1 block I think it's a bit stupid since I believe you need two on this board (unless somebody can tell me differently) so theoretically these should never be bought in 1's.

2 : I need a good way to remote mount the radiator and fans outside of and well away from the cabinet so it isn't laying around waiting for somebody to drop something on or put the boot in - are there any decent enclosures knocking about or is it a DIY job ....

Clunk · #2 09-03-2008, 22:54

If your PWMs are pumping out so much heat, you might want to try lowering the CPU voltage first, thats quite often the problem.

I had the same board a while back, and I used Zalman RAMsinks stuck onto the PWMs. They worked perfectly.

One thing I did notice is that the PWM area in general got much hotter when using the stock cooling.

Personally, I think that watercooled PWMs aren't needed, but if you really want to do it, you can easily get away with a single rad and a low rpm fan.

Blocks wise, I'm not sure, maybe drop Lee a PM in the watercooled-pcs forum?

External watercooling boxes are expensive, have a look at the Zalman Reserator XT

I think Silverstone do a similar one as well.

You can quite easily get a small PC case, gut it and then put the gear inside. It's just finding the right case

JabbaTheHutt · #3 09-03-2008, 23:40

I've had bad experiences with stick on heat sinks - i.e. falling off !! with terminal results on a previous Abit IC7G Motherboard - hmmm whats that smell, oh that's disgusting, then the random spurious characters hit the screen then lock up, shut down reboot - BANG, not only did the Motherboard die but it blew one of the PSU's regulators all over the inside of the PSU case - bits of molten solder and fluffy bits everywhere - and stink - we could smell it for days, and all because an aluminium heatsink fell off and ended up in a place where it shouldn't on the back of a graphics card.

It isn't that I want to water cool the PWM's it is just that the air circulation is poor and the inner cabinet ambient high with the door closed.

I just want to take as much heat as poss out of the cabinet as possible from as many sources as possible so I can leave cooler air for what else remains i.e. hard drive / memory.

To be honest I'm not sure what temp the PWM's or the Northbridge reach because there is no reporting from the board but last time I water cooled the sinks got to a temperature that became 'uncomfortable' to hold the finger on, the Northbridge shares the same heat sinks as one set of PWM's as does the Southbridge courtesy of heat pipes.

My CPU voltage is only 1.35V, any less and I can't keep things stable with the current clock.

The temperature starts to climb real quick the moment the cabinet door is closed so clearly air movement is the issue, currently with the door open I am running 46°C (Everest Sensors), if I close the door it hits 60°C and that's with a 22°C ambient in the room, the cabinet interior gets up to 35°C plus ... if anyone wanted proof how much heat PC's produce this is it. I keep it where I do because it is the coolest room in the house in hot weather.

As for the external cooling kits what a rip off I think they are, It would be nice to find some simple feet for the rad - like those in the Thermaltake 745 BW - as it is I will probably mount on the cear of the cabinet on standoffs of some sort (thats how I plan to mount the 250mm passive).

Clunk · #4 10-03-2008, 00:11

How about a Swiftech radbox to fit the rad to the back of the case?, as long as there is about 6-8 inches clearance at the back, you should be ok.

Or, what about the Thermalright HR-09 heatsinks? I've used them on the hottest of PWMs and they always work well.

Otherwise, it looks like a DIY watercooling job is on the cards