MCBrown.CA

Ok, so I recently bought a 45nm quad for my gaming rig. The CPU came with an awesome low-profile HS that's I never used because the CPU went under water right away.

OK, well this may not be a great HS for a OC'ed quad, but when I saw this thing it almost literally screamed 'GPU mod!!' at me... This has been done before, here.

Here's a comparison shot of a stock Q6600 HS and the Q9550 HS (with a pencil for scale). Quite a bit thinner!



Stupid me broke one of the mounting pins off of the Q9550 fan but I'm not going to end up using that fan anyway. Q6600 fan on left, Q9550 fan on right.



The fan that came with the Q6600 HS fits just fine and doesn't have the mounting pins in the way... lucky! I also have some spare half-height Enzotech ramsinks that I'll use on the memory chips if they'll fit.



This probably wouldn't be a good HS for a newer high-heat card. Luckily, I have a secondary rig that I will be using every day at school (2-year IT program). This rig's GPU is my trusty old eVGA 7900GS KO, which will be the guinea-pig in this project.



I took the stock HS assembly off and cleaned the thermal paste of the chip. I left the thermal padding for the memory chips on the stock HS in case this mod doesn't work out...



As you can see here, the screws that the stock HS was attached with were way too short to the reach the new HS.



I did some serious digging in my bitz bin to find some screws that might work to mount the new HS. Most were too short. In the photo below the HS is in the sitting nicely on the core but the screws were too short.



I found 2 long screws that look like they'll fit. I will have to buzz about a 1/4" or so off the ends with the Dremel so they won't hit the fan. Also, you'll notice that I had to bend the fins a bit to get the screws in there but I'll bend them back with some pliers when its mounted.



I need to go to a local computer shop and see if they have 2 more screws, but I don't have a car today so progress on this little mod will stop here for the time being...

If anyone has ideas about how to mount this thing, I'm all ears!

Thanks for watchin!



EDIT: Oops! Forgot some important testing info. 7900GS KO stock HS idle: 45 degrees



7900GS KO stock HS load: 60 degrees

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GANDALFtheGREY

i really have no experience with these kinds of mods but it looks like you've gotten a pretty good start on it! rep+ for ingenuity!

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Havegooda

Hmm, I'm intrigued...

*watches*

~Gooda~

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Photographer

i also once planned for something like this when the HS on my trusty old X550 conked off. i still have that card and a prescott 775 HS with me but then never got the time to complete it

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My Secondary rig

Qosmio G20,Pentium M 2.13Ghz,2X100GB HDD,2GB RAM,6600GT 256MB GDDR3,Toshiba TV Tuner,Harman Kardon Speakers,17" True Bright 1440X900 Display.

darksideleader

hmm, mabye i should do something about my card, some other guy has a k7 aftermarket fan on his 3870.

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e6550 @ 3.8ghz

MCBrown.CA

I have zero experience with this kind of mod either... but I have what I need to do it (except for those damn screws ) so I figure why not?

I am not really doing this to try to get better temps, though that would a nice side effect. I'm sure the CPU HS is designed to deal with a much higher thermal load that the stock HS on the 7900, so better temps won't be much of a surprise...

This GPU was overclocked when it was my main gaming card (can't remember the clock speeds) and I'll overclock it again after this mod is done...

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low strife

I should do that. I have identical parts, and will be using the x550 (but not in my computer).

The stock fan has been broken on for a year..

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superk

how secure is the HS on the card? It looks like a good bump could knoc it off..

I suggest trying to add some washers and bolts before adding the fan/cuttin the xcess. I dont konw how well that would work, but its worth a shot if you have them.

Nice idea for a mod though. Reminds me of the heatsinks palit uses, whcih reminds me of a zalman lol.

MCBrown.CA

In the photos above the HS is not securely attached at all, as I was experimenting with the best mounting method. I have found a solution thanks to your helpful idea... +1!! Now I can finish this today!

I found perfect washers and bolts for these screws which were actually part of the same mounting kit. I realized that I can only use 2 screws this width because they are only 2 mounting holes this size on the PCB. Along with nylon washers and bolts these 2 screws are a surprisingly secure mounting method. I can pick up the card by the heat-sink and feel no movement at all.



If I decided to use 4 screws, I would need 4 new screws that are slightly thinner than the 2 I am using now. Photo below should explain why. Holes that I'm currently using are circled.



Mounting the HS this way means I can't use the Intel fan as the bolts would hit the fan.



I think 2 screws will be enough. The HS's copper base looks like its flat on the core.



I had to bend the fins closest to the motherboard because the card couldn't fully plug into the PCI-E slot on the MB. There is a PCI slot right below which was a little too tall.



It doesn't look great but it will be invisible when the card is installed. Before the final mount I'll get in there with a tiny screwdriver and make sure the fins are rubbing at all...

I haven't applied TIM yet (will be using MX-2) because I want to hear some opinions about the 2-screw mounting method.

You guys think its secure enough?

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MCBrown.CA

Ok well since no one has any comments I bit the bullet and mounted the HS. I tightened the screws as far as they could go to be safe. As stated in the previous post, I used MX-2 thermal paste.



I wanted to see if the HS is working before I attach the RAM-sinks. So I threw it in my rig...



Problem

Bad news!!

Idle temps looked good at first, 40 degrees, 5 degrees lower than with the stock cooler.

So I started the artifact test on Atitool. After a couple minutes the GPU temp was at 72 degrees and rising... I turned off Atitool thinking the card would cool down, but a minute or 2 later the card was at 90 degrees!!

I turned off the system and took out the card. It was almost too hot to touch, and I'm pretty sure the HS could have burned me if I touched it directly...

Solution

I will need to put some active cooling on the card.

I have an extra 80mm fan that I will mount directly to the HS with zipties. If you look closely you can see its an AMD fan haha! I think its off my old Athlon64 3800+ stock HS.



I mounted the fan with 2 zipties each around 2 fins of the HS. The head of the ziptie acts as a wedge in the screw holes on the fan.



I also rigged up a 120mm fan to a rear slot cover pointing right up at the GPU to provide more airflow. I used a 1" long piece of double-sided foam tape and a ziptie. I was inspired to try this after stumbling across this thread.



Install the slot cover and presto, you have a decent secondary GPU cooler! In this case a Kaze Jyuni 1200RPM 68CFM... not bad (I am a big fan of these fans... lol).



The case that this card is going in is a CM Centurion 590 which has a side 120mm fan blowing right at the GPU which should help. Here's a photo.



The case is great for air-cooling. I have 2 intake and 3 exhaust 120mm's plus this internal 120mm now.

Finally, I mounted the RAM-sinks.



I only have 6 so two chips will be left uncovered. The other two are being used on my 8800GTX.

I will throw the card in it's system and do some tests. I hope I get better results that last time!

I'll post results in a few...

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