6600GT agp "ghetto" Prescottcooler & volt mod Project

[Lostfaith]

Intro:

it all started when I took out an old floppy drive and enabled the temperature monitoring for my PNY 6600GT AGP and was shocked to see idle temps at 66 degrees Celsius (stock clock settings!) and load pushing 77 degrees and on... I knew the ref. heatsink (same as nvidia's but with another pic printed on it) was running HOT and my little core overclock would render artifacts at 540+ core clocks)
needless to say my extra s478 Prescott's full copper core cooler I got from my friend that I've been eyeing for some time seemed like a good candidate for dealing with high temps

The card:

Die shot:

the Heatsink (almost the same model as in pic, the s478 prescott boxed cooler, only square and single fins):

Lapped sink (after 1 day testrun):

note the nvidia logo die markings on the copper core.

Equipment & parts I used:

lapping:
wet/dry Sandpaper grits 600/1500
mirror for sanding
water & dishwasher soap

canned air
alcohol 70%
earbuds
coolermaster thermal paste
screwdrivers.
nailclipper & tape for the p4 cooler connector mod to 2pin connector
4 cable ties (2.6mm wide)
small drillmachine with alloy composite disc for cutting edges of the heatsink.
3mm thick rubber matt cut in 4 pieces
bison kitt (glue 4 rubber pads)


Guides:
I hand-lapped the heatsink contact surface, here's a guide:
http://www.modsynergy.com/article6.htm

I modding the bios for temperature monitoring according to:
http://www.ocia.net/articles/tempmonitoring/page1.shtml

6600GT AGP Voltage Mod: (gave me 609/1.13 autodetection with optimal frequency detection while without it gave 551/1.08 which was artifacting too btw)
http://www.vr-zone.com/?i=1912&s=1


the construction:

first I removed the reference heatsink and cleaned the exposed core form the white thermal paste.
then I cut 4 spaces in 2 of the heatsink's corners (fanside & pcb side) where the cable ties' heads would go to avoid contact with the fanmount and where the holes are to avoid stress from the cable ties on pushing the heatsink away from the holes.

I cut the 3mm thick rubber mat into 4 square cm pieces, carefully cleaned them and glued to empty sposts on the pcb to combat wiggling of the heatsink. (this resulted quite unnecessary as the die and mounting hole alignment with proper heatsink mounting would result quite sturdy)
after the lapping part I tested out with various cable tie sizes, a pair of 2.6mm wide 14cm long ones would just fit through each mounting hole.

then came checking against the light if the copper core made full contact free of movement with the gpu-die and I put a thin layer thermal paste (coolermaster's crap) with a razor blade on the die.
next came the tricky part, securing the heavy heatsink with the cable ties.
I asked my girlfriend to lend me the needed extra pair of hands to hold the heatsink on the die while I carefully adjusted the cable tie pairs and tightened them.
I used the nailclipper to cut off the extra pieces of cable tie on both sides after I triple checked if everything was secure against the infamous wiggling of heatsinks: wiggling a problem? look here: http://www.anandtech.com/video/showdoc.aspx?i=2295&p=20

after modding the prescott cooler's 3pin connector to a 2pin one I put it on the heatsing and to my unpleasant surprise one of the fan mounting's corners canme off, luckily it stayed firmly on the heatsink so I put my worries away, made a small prayer (I can become truly religious doing these kind of things :P) and put the card back in my system hoping it would make windows without burning out...
to my delight: 48C idle @ 540/1125 clocks (GA-7nnxp +0.1Vagp) after running RTHDRIBL for 15 minutes 55Celsius (room temp = ~33C)

after the voltmod with the pencil trick (watch out, you need really good cooling for that, much better then with the stock heatsinks).
After the voltmod & pencil trick I'm running 617MHz/1175 core/mem clock without problems with only 57Celsius @load after 5 hours of 58-61fps RTHDRIBL v1.2 and running artifact free, with the old cooler I couldn't reach over 540 before getting artifacts within 2 minutes in rthdribl and 3dmarks.

Conclusion: If you like modding, and of course want the best performance with current means this kind of ghetto mod can surely be advantageous if done right. and just like I loved playing with technical LEGO when I was small, this kind of thing gives some real satisfaction when it works out.
If anything goes wrong, the old refernce heatsink can be put on again with no trouble so no real disadvantages except for tension, cursing and some skipping heartbeats too... :P


Running in system:

hey almost 4k 3dmarks!

somewhat embarrasing Cpu/mem performance clearly hold me back :P


anyway, it's up by over 500marks 3dmark2k5, ~1200 on 3dmark2k3 and about the same on 3dmark2k1 (cpulimited...)


about noise: I don't care about noise as I have 2 big Ventilators blowing in my room because life here in the tropics life is near impossible without them (30+ temps day & night and my room has a big 1/3rd wallsized window open 24/7) so screw noiseless systems for me, Im using 8 80mm case&psu fans just keep my system cool.

system setup:
using barton setup in sig @202x11, 76.44 XG @default drivers / nforce 5.10.
pny verto 6600GT agp using reference cooler and hsi bridge heatsink cooler.

IMPORTANT:
this mod is not possible for one piece hsi/gpu heatsinks as the hsi needs a heatsink coverage!


this was inspired by yaoyao "ghetto" duron heatsink mod.
http://www.vr-zone.com.sg/?i=1784&s=1

tnx to the authors of the guides I read all the time for their effort!
my bro G. for fixing me his drillmachine and special tnx to my Gf who had to endure my cursing at times when I was looking for stuff all over the room (uni's rooms are too small)

Oh and greetingz to y'all here, I'm a n00b

[DeltZ]

lol looks very neat nice job stock intel heatsink into good use..that's a new one :P

[[OvC] AMD Man]

good job

you could do more with some cooling on the mem

[tytlyf]

I have that same card, but why does yours look like it has more memory on it than mine, i just have 4. Here's my mod, haha

[sam3755]

LOL, I did that exact same mod with the 9800 Pro and the Prescott cooler. It might be ghetto, but hey do it right at youll get water cooling temps for the price of aircooling. My best oc with that card was 504/380. Here is a big tip, replace the Prescott fan with an 80MM vantec tornado rated at 84CFM (or any other high CFM fan). The Prescott fan sucks because it will not run at full RPM unless the heatsink gets very hot, I think they're only rated at about 30CFM.

[Nubius]

I have that same card, but why does yours look like it has more memory on it than mine, i just have 4. Here's my mod, haha

He doesn't have more memory it's just the little pads he put on there to support the heatsink I believe

[tytlyf]

yea, that makes sense. I guess to keep it from rocking from one side to another. That's an easy way to make sure you wont chip that gpu. Mine is chipped very slightly, one corner, but it hasn't showed an affect.

[Lostfaith]

yep, it's those lil rubber pads to support the die, as nubius said.

tnx for the tip sam, I'll be keeping an eye open for the fan.

and Tytlyf, been there when I replaced the HSF for a 3rd time... done it, but it survived seemingly flawlessly too after a few weeks heavy gaming etc.