High PWM temps with Abit IP35 Pro or other mobo?

[SerpentRoyal]

The heat sink is metal, so metal nut is fine. You don't need to add washer at the top. 70C is fine for PWM. Problem with IP35 is that the NB and PWM share the same heat sink. Heat from the NB will elevate the temp at PWM. IP35-E does not have this problem because it uses two separate heat sinks.

More clamping force may not improve temperature unless you have a fan blowing over the MOSFET region to lower the temp.

Others have seen 62 to 65C PWM with IP35-E and oveclocked 6600 quad.

 

[cytoSiN]

Originally posted by: SerpentRoyal
The heat sink is metal, so metal nut is fine. You don't need to add washer at the top. 70C is fine for PWM. Problem with IP35 is that the NB and PWM share the same heat sink. Heat from the NB will elevate the temp at PWM. IP35-E does not have this problem because it uses two separate heat sinks.

More clamping force may not improve temperature unless you have a fan blowing over the MOSFET region to lower the temp.

Others have seen 62 to 65C PWM with IP35-E and oveclocked 6600 quad.

Yeah that's basically what I'm using...OC Q6600 and IP35. I've considered tower sinks for the PWM and NB, but I'd have to get creative since the U-120 Extreme I'm using on my CPU kinda gets in the way. For now, I'd like to apply to AS5 and get some better coverage with the stock sinks, and see where that gets me, and a few dollars worth of bolts and washers seems worth it. Then again, my home depot doesn't carry fiber washers and I have no idea where else to get them.

Also, you say 70C is fine for PWM...assuming the NB is at least that hot, would that be fine too? Thanks.

 

[Hauk]

Don't use AS5 for the mofsets as it is slightly conductive. Use a thick thermal paste like Arctic Ceramique. If you orent you're 120 Extreme like I did mine, you'll have a good bit of clearance and more airflow to moffset.

Sounds like you have most questions answered. I picked stainless because it was only a few cents more. Non-conductive washer is the key.

 

[cytoSiN]

Originally posted by: SteelSix
Don't use AS5 for the mofsets as it is slightly conductive. Use a thick thermal paste like Arctic Ceramique. If you orent you're 120 Extreme like I did mine, you'll have a good bit of clearance and more airflow to moffset.

Sounds like you have most questions answered. I picked stainless because it was only a few cents more. Non-conductive washer is the key.

Thanks SteelSix, and thanks for posting the mod in the first place. I've got my U120 just like yours, with a 120mm Scythe pushing air through the fins and directly onto the PWM area. There's another fan right behind the PWM sucking air out the back, so in theory it should be nice and cool. I think the pipe from the NB and the lack of good contact aren't helping, so I want to try your mod. If all else fails, I'll remove the stock sinks (including the pipe) and put mini-tower coolers on the NB and PWM, assuming I can make them both fit around the U120.

I'll pick up some nonconductive TIM for the mosfets. Can I use AS5 on the NB, or do I need nonconductive TIM there too? AS5 on the CPU seems to be working well (cpu idles around 30, with cores a few degrees higher).

 

[SerpentRoyal]

Mosfet will be hotter because it's the output device. The MOSFETs are soldered to the MB's heat pad. Therefore, most of the heat will flow into the MB.

Look at home audio amplifier or PSU. The back of the output device is bolted to a large heat sink for cooling. Cold air is directed at the heat sink to control temperature.

 

[Hauk]

Yea you can use AS5 on the NB die not problems. Reason you want non-conductive white paste is you'll need a good size bead on top of each mofset to compensate for the thickness of the stock thermal pad that you'll be removing. Some will goop onto the leads as you reinstall heatsink but that's okay.

I used a Thermalright HR-05 for my last NB, I can understand the desire to go with tower cooling. But the stock solution for the IP35 PRO will work just fine so long as it's making optimum contact. As Serpent said, airflow matters too.

 

[mjd1964]

http://www.qwikflow.com/DC_Fans/dc8025-Blower.pdf

DC Blower Fan.

Stuck one of these over the PWM heatsink. Droped temps from 85C to 55C @ 3600mhz 1.41v.

I removed the pad and heatpipe used artic white thermal compound on the mosfets.
I use water cooling so air flow in that area was bad.

 

[imported_halcy]

has anyone tried using the existing push pins for the NB/SB, but using bolts for the mosfets? I'd like to try and keep as little metal as possible sticking up near my cards

 

[SerpentRoyal]

Originally posted by: halcy
has anyone tried using the existing push pins for the NB/SB, but using bolts for the mosfets? I'd like to try and keep as little metal as possible sticking up near my cards

You can manually bend the heat pipe to ensure that the MOSFET heat sink is flush with the output devices. Air cooling is a must if you want to push a quad north of 3.2GHz.

http://forum.abit-usa.com/show...ad.php?t=128310&page=4

 

[imported_halcy]

Finished doing this, I ended up going with 4-40x1/2" bolts, they still have plenty of thread sticking up, you could probably get away with 7/16 or so length if you could find them and be fine. Also I couldnt find any nylock nuts that are 4-40, so I used some lockwasher and regular nuts. Put a 60mm Ystech fan blowing on it at 8V.

Temps dropped from ~86C to ~71C, running at 3.5ghz 1.48V chip voltage in the bios.

I also noticed that my heatpipe going from the mosfets to the northbridge, right before it enters the northbridge appears to be pinched or kinked, anyone else notice something like this?

 

[cyborg939]

Your pictures for the High PWM temps for IP35 Pro are not available on photobucket. I was planning on doing the mod, and would like some help. Thanks

 

[Earfoam]

Originally posted by: SerpentRoyal
You believe what you want to believe. I stand behind my post with concrete scientific data.

You're a scientist too??? :roll:

(about as scientific as those myth-buster clowns)

Mr. Wizard what CAN'T you do?

gotta hand it to you Serpant, you generate some great belly laughs................

 

[MegaWorks1]

Maybe you should change your motherboard with the IX38 QuadGT to get better PWN temps.

 

[BassKozz]

Originally posted by: cyborg939
Your pictures for the High PWM temps for IP35 Pro are not available on photobucket. I was planning on doing the mod, and would like some help. Thanks

I am also in your boat cyborg939,
I just purchased this board and wanted to do this mod and would love to see these pic's...

There are some pics on XS's forum:
Here
and Here