Upgraded Cooling = Loss of Overclock

[J-Mag]

I finally got around to installing secondary cooling for everything in my machine...

I replaced the Stock A64 Sink w/ an XP120 and the Stock Asus chipset fan (a8n-sli) with a Zalman NB47J + a 92mm Zalamand fan pointed at the NB. I also put two of the VF700-Cu 's on my 6800GT's. I had to clip a few of the pins off the NB sink in order to get it to fit with the VF700-Cus, so the NB sink is quite close to the primary vid card sink.

Now I am 100% positive that before the replacement I was able to do 2.4ghz w/ 266 FSB no prob w/ my OCZ 4200EL plat. Now I can only push 250mhz( even at 3-4-3-8 2t), if I try to set at 266 I get an immediate BSOD that mentions an Nvidia ata file of some sort.

Could it be that my NB sink installation was bad? I didn't think that the NB on an nforce4 was really handling the memory intractonnect. That leads me to believe that I might have the remount my XP120.

The one other thing that I did was I swapped placement of the DIMMs before I put the XP120. <--- Is this a likely cause of a decreased overclock?

Edit: temps are fine btw... My idle CPU temp is 28C system 32C...
one more thing: I moved the 92mm fan from blowing over the DIMMs b/c it seems there is some decent flow coming off the XP-120 that is hitting the dimms...

[scrible88]

Try reseating your NB heatsink.

[J-Mag]

Try reseating your NB heatsink.

Thats my though as well, but is the NB on an nforce4 actually running at the speed you set for memory or is it running at HTT speed?

Also another thought came into my mind: The new fan I am using on my XP120 runs with 2.4W 0.20A. This is well within the spec of the board, but is definatley more juice than the stock Fan. Also I have noticed that it takes a good 5-10secs before the fan is at max speed.

I know that this is an easy thing to check, but has anyone else experienced a change in overclock form removing all fans from the MB headers?

[MrQ3W]

Sounds like overclocker's superstition, you probably just reset BIOS and forgot to put some setting back.
Placement of the DIMMs might be the cause still, perhaps you were running single channel before?
I hardly doubt it is anything overheating though, like you said it's upgraded and you probably know exactly what you're doing. You just missed some little thing somewhere, usually easiest way to find it is to reverse everything to how it was before.

[RAMMIE]

Plug the fan into PSU.Only thing is it will run full speed all the time.I wouldn't run a fan like that off a header.

[oublie]

Problem:

Two things have changed
1. your sucking more power from your psu
2. youve removed and replaced some components.

Reason I suspect:

1. All the extra cooling will be sucking power from your mb / psu leaving less for the chips this might also be a cause depending on how good your psu is.
2. will take time for as or whatever paste you use to bed back in i.e. you'll get better clocks once youve let that bed in (about a week or so)

give it a week and see how it is :)

[Major]

The one other thing that I did was I swapped placement of the DIMMs before I put the XP120. <--- Is this a likely cause of a decreased overclock?

Thats where I would start, put them in dimms 2 & 4

Chipset cooling should have no impact on your OC with NF4

[J-Mag]

Thanks for the replies :toast:

MrQ3W: Well, I know for a fact I was runnel dual channel previously. BIOS wise, I didn't even alter any setttings, just swapped out all the cooling... (although I wasn't familiar with the mounting procedures, so it wasnt a smooth mount... You know when you push down a clip or a pin and it doesn't lock then you have to do it again, well i did that for both the NB sink and just a tad on the XP-120)


RAMMIE: The Asus manual states that fans of up to .5mA with a total of 1amp can be run off the mobo headers... Has there ever been any conclusive study done on the differences of overclocks with fans running off MB header vs PSU directly?

oublie: I am always concerned about power draw, funny enough i am using my lowest rated (in watts) of 3 three PSU's I have... it is a 400w Zippy +3.3V@25A, +5V@35A, +12V@30A. My 510w turbo cool eps12v actually gave the board all sorts of stability problems oddly enough (but I have had this one RMA'd so it might not have been completely fixed). Anyway, the PSU load only increased by maybe 500mA on the 12v at the most... Anyone know what the stock GT cooler fan draws?
I guess your second point is true, I put in AS5 on the NB and CPU, also replied some white silicon paste to the Mosfet sink (btw, it is scary how much white goup Asus had on the thing stock, it was definatley covering and bridging all the mosfet pins, I hope the stuff i used is non-conductive!!!)

Major Slaughter: Well the dimms are in slots 2 and 4, but I just swapped the sticks themselves...

[J-Mag]

Last night I unplugged everything I didn't need and left only 2HD's 1 DVD.
It still seems as if I lost some overclock. 266 mem clock is still an instand BSOD.

Then I tried moving the 3pin 120mm fan connect off the MB and feed it directly by the PSU, stilll no go.

I know it can't be temp related, because I jacked up the CPU speed to 2.4ghz with a 5:6 divider and it ran stable. Primie95 for a couple hours and the max CPU Temp was 42.

So the only other thing I could change i guess is swapping the dimms, but i really don't feel like disassembling everything just to swapp dimms (I guess thats the main disadvantage of the XP120)

Is it possible that my memory controller is borked?