Why don't we see more people cooling their mosfets? - Page 2

Puzzdre · 12-05-2003, 06:43 PM

This little piece chopped from an old duron cooler did miracles in my OC stability. Just scraped some goo from a bottom side of an unused NB cooler (the pink stuff that plays the role of thermal interface) and used it to 'glue' the sink to the mosfets. Holds great, no problems, but not too resistant on sideloads:

V12|V12 · 12-06-2003, 04:22 AM

Blade... Okay, forgive me, cause I'm a little intox'd... but saying that adding passive heatsinks is a bad idea or a disfavorable one doesn't seem to follow much logic at all to me? Adding ANY sort of extra cooling to components does WORLDS of difference for them (FACT.) And as far as the radiant heat that the heat sink distributes to them is null, for the simple reason that, IF you leave component "A" non cooled, where does that heat go? It get's TRANSFERED to the mobo and the other surrounding components on the board (a lot etc...). So, by adding a passive heatsink (etc.) you are providing a heat outlet for not ONLY the primary object to be cooled, BUT it also relieves an AREA (be it small, but on a crowded mobo small is relative) of transfered heat... based on the fact that the primary object to be cooled is NO longer dumping it's extra heat load back to the mobo PCB, which other components have to share and absorb. Each surface mounted object on the mobo acts as some sort of small heat outlet... by significantly cooling ONE specific component, you are actually contributing to cooling a small lalent heat area of other objects, as with the fact that now there is 1 less heat inducing factor in the small footprint (heat) area, therefore ANY sort of cooling helps, there 's no way that by adding a heatsink to comp A- makes Comp-B worse off, unless it now has to handle more heat load brought on by the radiant heat form the heat sink, okay this is sounding like a repeat....

Either way, even with that extra heat now being distributed by the heatsink, it's still MUCH less that if you didn't have it at all and the mobo was saturated with a bunch of IC's giving off heat and for it (heat) nowhere to go, but reside around the components... I hope this is making sense... haha Good night all!

BladeRunner · 12-06-2003, 01:20 PM

V12|V12

You either misread or misunderstood what I was saying or didn't follow my original post link, I never said or meant to imply " that adding passive heatsinks is a bad idea or a disfavorable one " I said almost the opposite in fact ..."I'd agree with you in MOST situations"

I've quoted the relevant text from that linked topic below:-

Quote:

I too noticed the heat of these on my NF7-S and tried a heatsink (modified P3 slot) without much improvement. I then made a waterblock that has solved the heat of the fets and associated components in the area. It seems whatever you do someone has always beaten you to it. I water cooled mine a while ago and I'm sure I'm not the first to do it either. In a fanless system I was getting around 80°C naked, 68°C with sink, and 33°C with waterblock. For retention I also used epoxy, (artic sliver), but mixed with AS3 so it remains a little rubbery. This should allow me to be able to remove it later without ripping components from the PCB.......in theory at least, (I mounted the heatsink the same way and that came off with some gentle prying)

My point is the sink I used did help a bit, but not enough to make it a solution for me in a zero fan system. Heatsinks by their nature absorb the heat but if there is very little air movement around the sink area to remove the heat, it can get overcome with the heat itself and heat up to near the same temp as what it's cooling. This is what I found with my system, not opinion just a fact. I'm sure a small low speed fan would have helped a lot, but no fans allowed..........

As you say in using a sink there should be less heat for the component it's mounted on than with no sink, but it did make the caps get hotter probably because of the way I drilled hole relief's in the sink for them, which meant they were enclosed by the hot sink.

I guess I could have persevered with bigger and different passive sinks, but knew a small simple waterblock would solve the issue completely, not only cooling the fets but the whole area. It wasn't much of a problem to add in due to my split distribution set-up.

I think a lot depends on how hot the fets get on a particular mobo, on my NF7-S 2.0 they seem to run very hot, certainly much hotter than any previous mobo.....

Tempus · 12-06-2003, 01:35 PM

My SK8N runs extremely hot when OCed. Runs hot just normally. I've been pondering cooling anything remotely hot on it.

Anyone have suggestions?

BladeRunner · 12-06-2003, 02:09 PM

Tempus

Nice I'm tempted to get FX51 but put off by the nforce 3 issues atm, and just cannot convince myself to venture down the via mobo road again........

If you got some pics or links to decent pics of the board post them, I'll look later if not.......

Tempus · 12-06-2003, 02:26 PM

via??

The SK8N is a nvidia Nforce3 Pro 150 mbo =) The SK8V is the Via chipset.

Not that I dislike my via chipset ones. They've been good to me too.

I'll get a close up posted soon.

Heres the website image:

http://usa.asus.com/products/mb/sock.../overview.htm#

BladeRunner · 12-06-2003, 02:36 PM

No you misunderstood me....I was talking generally........ to use FX51 I need either nvidia (nforce 3) or via both or which I'm not fully happy with atm..... at least not to justify the upgrade costs

This is especially so considering the NF7-S v2.0 is spiritually the closest I've come to anything that matches the BX chipset mobos (best of all time imo), never fully enjoy my time with various via mobos always some annoying issue that never get solved fully......

Tempus · 12-06-2003, 03:50 PM

ahh.. I gotcha now.

And, yes, I can see where you are coming from.

Personally, I liked my Abit VP6. I thought that was "the next BX" series with its dual procs for the masses and plenty of OCing options.

I'm not a big fan on the NF3 pro 150 my self. But its how it all happened so I'm not arguing. I do agree that there isn't an utterly compelling S940 board / chipset out there yet. I know its coming. They just need more sales #s to get there.

V12|V12 · 12-06-2003, 07:42 PM

Blade,
Yeah sorry bout that, I was intox'd last night and misread the whole thing! Lol, yeah 0-zero airflow makes the heat sink very limited, I see what you meant now that I'm clear minded! WHen I first saw the layout of your cooling system, I was thinking, WHOA wtf, I've GOTTA see hi's Hcore...but you don't have one, even better, UNDERGROUND, I remember reading about that a long time ago, very, very nice... How did you make the rest of the components, you have your own mill? CNC? I wish I could find a cheapo manual (like Couple $100) at an auction, or else I'll never have one, they are just too pricey for my limited use of one, though I would start building all kinds of automotive/computer toys.... For now, i'm still hunting down a SMALL X-Y Table for my cheapo Drill press, with no luck, since it's a small 8" model..... Nice System

BladeRunner · 12-07-2003, 01:48 PM

I acknowledge that you are right, and my system is "different"

90% of the time a heatsink will do the job for most cooling tasks....... as long a there is some airflow........

My PC is in storage atm so I'm relegated to the humility of having to use a laptop

I did however use a "Normal Rad & Fan"

for a while before moving, as I had to disconnect from the underground tank.......

I made all the water-blocks in the system & although I have a proper mill now, (its still an entry level model imo), you can get by with very basic tools if need be. Have a look a the build projects on my site as most were made with hand tools or a horrid drill press and x-y table.

A lot of it comes down to dedication and time, not my creation, but if you haven't seen this yet it shows just what can be done with limited tooling..... (pic is link and read my post in the thread)

rocketmanx · 12-07-2003, 09:49 PM

I saw that Hydrae as well bladerunner

That guy is a real craftsman, I envy his skills. That is a gorgeous piece of work. It's art as well science. Wish He'd sell some.

superart · 12-07-2003, 11:25 PM

What is that black coating inside of the block?

BladeRunner · 12-08-2003, 04:53 AM

superart

Click the pic as it's a link, and my last post there details how the main part was made with a drill press. the black coating you think you are seeing is just the channeling

superart · 12-08-2003, 08:50 AM

Yea, I read that, but just couldn't find anything about the coating.

Aperantly, its because there is no coating. Just a shadow. Thanks.

Tic · 12-08-2003, 10:45 AM

Hej guys. In know it is a little offtopic, but still :>
btw, sorry 4 my english ...

When I had stock (no) cooling on mosfets, i could run my AMDXP 1700+ @ 2.05V. Now i puted some heat sinks and one 80mm fan from zalman (can"t hear it on 7v) and i can run my AMD on 2.175 no prob. I get BSOD on 2.2V

It is worth to put something there. It assures stable voltages and higher too. I just wouldnt put H2O cooling there. There is no need. You can still have silent PC with one 80cm fan.

Tic

BladeRunner · 12-08-2003, 12:38 PM

Yeah that's what I meant the way the photo was taken makes it look black.

Lets not do this "silent fan" thing again, I've not yet come across a "silent fan", some 12db rated pabsts I got were far from silent even at 7v......... it more depends on how quiet your environment is to what you may perceive as "silent"

Regardless it would also be a little silly having worked hard to get a completely fanless system to then put one in just to effectively cool a mobo powerfet sink

Ketchak · 02-05-2004, 06:04 PM

Quote:

Originally Posted by BladeRunner

superart

Click the pic as it's a link, and my last post there details how the main part was made with a drill press. the black coating you think you are seeing is just the channeling

The complete guide of Hydrae construction.

In spanish languaje but with many pics.

Ketchak.
www.devilmaster.org

Starman97 · 02-06-2004, 02:39 PM

What I would do to cool the CPU VCORE supply(ies) is to mount a water cooled
plate on the backside of the motherboard. It's stealthy and will work nearly as well
as trying to make contact with all the devices and their various component heights.

The board maker puts a whole lot of copper in the power supply area to help dissipate
the heat from the FETs , inductors and caps. The back side of the board usually has few if
any components so you can make good contact over a large area. You might have to use a
conformal pad if there are some small surface mount caps there. Also will have to grind
down any protruding leads from inductors or electrolytics. But you only have to take out
10-20W over a 4 square inch area, so it's not like mounting to a bare CPU die as far as heat
transfer efficiency goes.

TerraMex · 02-06-2004, 02:52 PM

http://www.alphacool.de/upload/images/12307D.jpg
http://www.alphacool.de/upload/images/12311D.jpg

Some companies have already jumped on it.

Starman97 · 02-09-2004, 11:16 PM

Quote:

Originally Posted by TerraMex

http://www.alphacool.de/upload/images/12307D.jpg
http://www.alphacool.de/upload/images/12311D.jpg

Some companies have already jumped on it.

Those are nice little blocks, but they are only going to work on a specific
motherboard that has the FET's positioned in the same geometry as the
waterblock surfaces. From what I've seen, no two mobo's are alike in the CPU
power department. I'd still go for the large area back of the Mobo cooling idea.
I've picked up and looked at a lot of boards at Fry's, almost every one of them
is nice and flat on the back under the CPU power supply. Cap and inductor leads
and scattered 0603 sized caps are the only exceptions. So a nice silpad should
take up the gap and with enough area you should get 20W of heat transfer.
Even at 1Degc/W you are removing heat.

But this is all for a WC purist, gluing a small chunk of heatsink to each FET
and putting an 80mm fan at 7v will do just as good of a job and not add much
noise at all. The wound core inductors have tons of surface area and really
are quite efficient compared to the square surface mount inductors that can
be heatsinked.

Bottom line, dont ignore the CPU supply, it's designed for a fan cooled CPU
, when you watercool, you remove a lot of the local airflow and that supply can overheat, especially when you overclock.

Zhentar · 02-10-2004, 09:24 PM

I noticed a serious drop in stability once I stopped cooling my MOSFETs... mostly because the capacitors next to them exploded. I'd definately recommend some sort of MOSFET cooling.

I wish I could make a MOSFET block but all I've got here is a dremel

Edit: Holy crap that's a waterblock Bladerunner.

TerraMex · 02-10-2004, 10:25 PM

The first one is for the NF7 only, the second one, well, you can just stick it where you want it.
They are, however, for aquacomputer/innovatek systems.
Not particulary good for others.

Exploding capacitors is a known issue with some motherboard manufacturers that purchased second grade capacitors. Not mosfet heating.
RMA it (assuming it's not an old board) , you should be eligible.
Specially if it's a Asus board.

12-06-2003, 04:22 AM	#27
V12\|V12 Cooling Savant Join Date: May 2002 Location: Ohio-State! <--Money Hussle! SUCKS Posts: 292	Blade... Okay, forgive me, cause I'm a little intox'd... but saying that adding passive heatsinks is a bad idea or a disfavorable one doesn't seem to follow much logic at all to me? Adding ANY sort of extra cooling to components does WORLDS of difference for them (FACT.) And as far as the radiant heat that the heat sink distributes to them is null, for the simple reason that, IF you leave component "A" non cooled, where does that heat go? It get's TRANSFERED to the mobo and the other surrounding components on the board (a lot etc...). So, by adding a passive heatsink (etc.) you are providing a heat outlet for not ONLY the primary object to be cooled, BUT it also relieves an AREA (be it small, but on a crowded mobo small is relative) of transfered heat... based on the fact that the primary object to be cooled is NO longer dumping it's extra heat load back to the mobo PCB, which other components have to share and absorb. Each surface mounted object on the mobo acts as some sort of small heat outlet... by significantly cooling ONE specific component, you are actually contributing to cooling a small lalent heat area of other objects, as with the fact that now there is 1 less heat inducing factor in the small footprint (heat) area, therefore ANY sort of cooling helps, there 's no way that by adding a heatsink to comp A- makes Comp-B worse off, unless it now has to handle more heat load brought on by the radiant heat form the heat sink, okay this is sounding like a repeat.... Either way, even with that extra heat now being distributed by the heatsink, it's still MUCH less that if you didn't have it at all and the mobo was saturated with a bunch of IC's giving off heat and for it (heat) nowhere to go, but reside around the components... I hope this is making sense... haha Good night all! __________________ XP 1600+ AGOIA-Y (GreenLabel, UNLOCKED!@/ NF7-S 2.0/ PC 2700 DDR 10.5*172FSB(1806/ 1991 high), Vcore 1.792...@84.95Watts --86' Chevette Heater Core --1/2" Vinyl tubes --Via1300-Stealth Mod(QUIET!) ---Home made copper-tube block ---PVC small internal res

12-06-2003, 01:35 PM	#29
Tempus Cooling Savant Join Date: Jul 2003 Location: Michigan, USA Posts: 456	My SK8N runs extremely hot when OCed. Runs hot just normally. I've been pondering cooling anything remotely hot on it. Anyone have suggestions? __________________ Thou art God.

12-06-2003, 02:09 PM	#30
BladeRunner Cooling Savant Join Date: Jul 2001 Location: Chesterfield Uk Posts: 459	Tempus Nice I'm tempted to get FX51 but put off by the nforce 3 issues atm, and just cannot convince myself to venture down the via mobo road again........ If you got some pics or links to decent pics of the board post them, I'll look later if not....... __________________ Zero Fan Zone

12-06-2003, 02:26 PM	#31
Tempus Cooling Savant Join Date: Jul 2003 Location: Michigan, USA Posts: 456	via?? The SK8N is a nvidia Nforce3 Pro 150 mbo =) The SK8V is the Via chipset. Not that I dislike my via chipset ones. They've been good to me too. I'll get a close up posted soon. Heres the website image: http://usa.asus.com/products/mb/sock.../overview.htm# __________________ Thou art God.

12-06-2003, 02:36 PM	#32
BladeRunner Cooling Savant Join Date: Jul 2001 Location: Chesterfield Uk Posts: 459	No you misunderstood me....I was talking generally........ to use FX51 I need either nvidia (nforce 3) or via both or which I'm not fully happy with atm..... at least not to justify the upgrade costs This is especially so considering the NF7-S v2.0 is spiritually the closest I've come to anything that matches the BX chipset mobos (best of all time imo), never fully enjoy my time with various via mobos always some annoying issue that never get solved fully...... __________________ Zero Fan Zone

12-06-2003, 03:50 PM	#33
Tempus Cooling Savant Join Date: Jul 2003 Location: Michigan, USA Posts: 456	ahh.. I gotcha now. And, yes, I can see where you are coming from. Personally, I liked my Abit VP6. I thought that was "the next BX" series with its dual procs for the masses and plenty of OCing options. I'm not a big fan on the NF3 pro 150 my self. But its how it all happened so I'm not arguing. I do agree that there isn't an utterly compelling S940 board / chipset out there yet. I know its coming. They just need more sales #s to get there. __________________ Thou art God.

12-06-2003, 07:42 PM	#34
V12\|V12 Cooling Savant Join Date: May 2002 Location: Ohio-State! <--Money Hussle! SUCKS Posts: 292	Blade, Yeah sorry bout that, I was intox'd last night and misread the whole thing! Lol, yeah 0-zero airflow makes the heat sink very limited, I see what you meant now that I'm clear minded! WHen I first saw the layout of your cooling system, I was thinking, WHOA wtf, I've GOTTA see hi's Hcore...but you don't have one, even better, UNDERGROUND, I remember reading about that a long time ago, very, very nice... How did you make the rest of the components, you have your own mill? CNC? I wish I could find a cheapo manual (like Couple $100) at an auction, or else I'll never have one, they are just too pricey for my limited use of one, though I would start building all kinds of automotive/computer toys.... For now, i'm still hunting down a SMALL X-Y Table for my cheapo Drill press, with no luck, since it's a small 8" model..... Nice System __________________ XP 1600+ AGOIA-Y (GreenLabel, UNLOCKED!@/ NF7-S 2.0/ PC 2700 DDR 10.5*172FSB(1806/ 1991 high), Vcore 1.792...@84.95Watts --86' Chevette Heater Core --1/2" Vinyl tubes --Via1300-Stealth Mod(QUIET!) ---Home made copper-tube block ---PVC small internal res

12-07-2003, 01:48 PM	#35
BladeRunner Cooling Savant Join Date: Jul 2001 Location: Chesterfield Uk Posts: 459	I acknowledge that you are right, and my system is "different" 90% of the time a heatsink will do the job for most cooling tasks....... as long a there is some airflow........ My PC is in storage atm so I'm relegated to the humility of having to use a laptop I did however use a *"Normal Rad & Fan"* for a while before moving, as I had to disconnect from the underground tank....... I made all the water-blocks in the system & although I have a proper mill now, (its still an entry level model imo), you can get by with very basic tools if need be. Have a look a the build projects on my site as most were made with hand tools or a horrid drill press and x-y table. A lot of it comes down to dedication and time, not my creation, but if you haven't seen this yet it shows just what can be done with limited tooling..... (pic is link and read my post in the thread) __________________ Zero Fan Zone Last edited by BladeRunner; 12-07-2003 at 01:58 PM.

12-07-2003, 09:49 PM	#36
rocketmanx Cooling Savant Join Date: Nov 2003 Location: Indiana Posts: 127	I saw that Hydrae as well bladerunner That guy is a real craftsman, I envy his skills. That is a gorgeous piece of work. It's art as well science. Wish He'd sell some.

12-07-2003, 11:25 PM	#37
superart Cooling Savant Join Date: Mar 2002 Location: FL Posts: 787	What is that black coating inside of the block? __________________ When you do things right, people won't be sure youv'e done anything at all. Looking to buy/trade for used Deep Fryer and Vacume Pack Sealer.

12-08-2003, 04:53 AM	#38
BladeRunner Cooling Savant Join Date: Jul 2001 Location: Chesterfield Uk Posts: 459	superart Click the pic as it's a link, and my last post there details how the main part was made with a drill press. the black coating you think you are seeing is just the channeling __________________ Zero Fan Zone

12-08-2003, 08:50 AM	#39
superart Cooling Savant Join Date: Mar 2002 Location: FL Posts: 787	Yea, I read that, but just couldn't find anything about the coating. Aperantly, its because there is no coating. Just a shadow. Thanks. __________________ When you do things right, people won't be sure youv'e done anything at all. Looking to buy/trade for used Deep Fryer and Vacume Pack Sealer.

12-08-2003, 10:45 AM	#40
Tic Cooling Neophyte Join Date: Dec 2003 Location: Slovenia Posts: 8	Hej guys. In know it is a little offtopic, but still :> btw, sorry 4 my english ... When I had stock (no) cooling on mosfets, i could run my AMDXP 1700+ @ 2.05V. Now i puted some heat sinks and one 80mm fan from zalman (can"t hear it on 7v) and i can run my AMD on 2.175 no prob. I get BSOD on 2.2V It is worth to put something there. It assures stable voltages and higher too. I just wouldnt put H2O cooling there. There is no need. You can still have silent PC with one 80cm fan. Tic __________________ Barton @ 2503mhz FSB 226 - 1:1 GFFX 5900 LX 559 / 975 MHz on AIR OCZ EL 3500 7,3,3,cl2 19203 3D Mark 2001 Tic Slo-Tech 3D Team

12-08-2003, 12:38 PM	#41
BladeRunner Cooling Savant Join Date: Jul 2001 Location: Chesterfield Uk Posts: 459	Yeah that's what I meant the way the photo was taken makes it look black. Lets not do this "silent fan" thing again, I've not yet come across a "silent fan", some 12db rated pabsts I got were far from silent even at 7v......... it more depends on how quiet your environment is to what you may perceive as "silent" Regardless it would also be a little silly having worked hard to get a completely fanless system to then put one in just to effectively cool a mobo powerfet sink __________________ Zero Fan Zone

02-06-2004, 02:39 PM	#43
Starman97 Cooling Neophyte Join Date: Oct 2003 Location: Austin,TX Posts: 27	What I would do to cool the CPU VCORE supply(ies) is to mount a water cooled plate on the backside of the motherboard. It's stealthy and will work nearly as well as trying to make contact with all the devices and their various component heights. The board maker puts a whole lot of copper in the power supply area to help dissipate the heat from the FETs , inductors and caps. The back side of the board usually has few if any components so you can make good contact over a large area. You might have to use a conformal pad if there are some small surface mount caps there. Also will have to grind down any protruding leads from inductors or electrolytics. But you only have to take out 10-20W over a 4 square inch area, so it's not like mounting to a bare CPU die as far as heat transfer efficiency goes.

02-06-2004, 02:52 PM	#44
TerraMex Cooling Savant Join Date: Nov 2002 Location: Portugal, Europe Posts: 870	http://www.alphacool.de/upload/images/12307D.jpg http://www.alphacool.de/upload/images/12311D.jpg Some companies have already jumped on it. __________________ "we need more cowbell."

02-10-2004, 09:24 PM	#46
Zhentar Cooling Savant Join Date: Apr 2003 Location: Madison, WI Posts: 225	I noticed a serious drop in stability once I stopped cooling my MOSFETs... mostly because the capacitors next to them exploded. I'd definately recommend some sort of MOSFET cooling. I wish I could make a MOSFET block but all I've got here is a dremel Edit: Holy crap that's a waterblock Bladerunner.

02-10-2004, 10:25 PM	#47
TerraMex Cooling Savant Join Date: Nov 2002 Location: Portugal, Europe Posts: 870	The first one is for the NF7 only, the second one, well, you can just stick it where you want it. They are, however, for aquacomputer/innovatek systems. Not particulary good for others. Exploding capacitors is a known issue with some motherboard manufacturers that purchased second grade capacitors. Not mosfet heating. RMA it (assuming it's not an old board) , you should be eligible. Specially if it's a Asus board. __________________ "we need more cowbell."

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