Ok, so here we go. this is my first mod that I'm documenting and trying to disclose, so forgive me if it's not perfect. I was preparing for this mod for a while and when I had everything together- my camera broke. so little late, now let's get to it.
I decided a while ago upon seeing a cooling mod ( http://www.rojakpot.com/showarticle.asp ... 246&pgno=0
) involving a use of a thermalright SI-97 Socket A heatpipe cooler and a 9800pro that I will try to do the same - except with a different card.
my plan was to get a 6800LE and first try to open the pipes with riva tuner and if
that was a success, then get the SI-97 and go ahead with the mod.
I bought an Inno3d 6800LE. I chose this particular card because it has the same exact PCB and reference nvidia cooler as the 6800GT, so it is actually a 6800GT in disquise having the same gddr3 256MB 2.0ns memory and running at 1000mhz ddr.
when I got the card, ran a 3dmark05 benchmark to see what is the performance at default. it was as I expected 2900 points at default speed of 300/1000. then I proceded with opening the pipes with riva tuner and was glad to see that it was a complete succes.
I ran 3dmark05 to see what is the difference : 4310 points at default speed. next I OC-d the card to GT speeds and checked for any artifacts. non found. so far so good. at the default 1.1V for 3D I wasn't able to go above 385Mhz on the core so the next thing was to try and make a little voltmod, to change 3D volts from 1.1V to 1.3V as in the GT version. for that I had to save my own cards bios and with a little app. called Nibitor change the volts and then save the modded bios and reflash my card. at this point i still had no idea how to do this, so I went MVKtech forums that specializes in video cards ( http://www.mvktech.net/index.php
) and got all the help on how do all these steps. I want to thank for all the help I got there especially to Mavke and Jutthope21.
now that I was sure my card can operate at GT speeds and above, I was ready to flash my cards bios with an Inno3d 6800GT bios. I was hoping to get the temperature readings in control panel that is enabled in the GT bios and not available with my LE. after flashing with the GT bios, I still had no temperatures displayed in control panel and despite trying and flashing with different bioses, to no avail. since knowing the temperatures of the core is essential when OC-ing a GPU, I had to get a little display with a sensor and install it on the core. I checked the temps with the reference cooler installed and OC-d the card to 425/1100 running 3dmark05 with no artifacts and a great score of 5696! . at this point I wasn't trying to push with OC, just wanted to see the temps.
my idle temps with stock cooling were:34C
at full load running 3dmark05 the highest temp was 59C, which isn't bad considering I was 5mhz passed the Ultra speeds.
now I was ready to proceed with the mod:
here are the ingredients:
Inno3d6800LE card, thermalright SI-97, zalman OP-1 fan, arctic silver5, 4x 3cm screws, temp. display with sensor.
I wanted to use as many of the original parts as possible, without having to cut or modify any of them, so that I would be able to change everything back to stock in case of wanting to sell the card in the future. the beauty of this mod is that I can return everything to original and keep the SI-97 for my next victim (card)
so I decided to use the original fins and the bottom retainer to secure the new cooler. all I had to do is get longer screws that can do that. my measurements showed that I need them to be 3cm long and 2mm thick. the original screws are not metric and 2mm metric size screws are just slightly thinner so they can pass through all the holes without having to make them bigger. I had to get 4 screws, 8pc. nuts, and 12 washers.
here is the next step:
David and Goliath (who do you think will win this time?
) + the back bracket.
I recommend putting nuts as well on the other side to hold the screws in place.
next I had to attach the temp sensor and put a thin coat of arctic silver on the GPU (be carefull- the little sensor ending cannot go between the GPU and cooler, because it gets squashed and become useless- instead I put the little plastic ending on the GPU and the sensor is touching from the side) :
next assemble the top fin with the back bracket using the 3cm screws (with all the washers. make sure there is enough space between the GPU and the top cooler to put in the base of the SI-97 between them:
slide in the SI-97 as far as it can go in hitting the ram cooler. if not all the way in, there will be not enough space to install the card in the AGP slot. in fact even like that the heatpipes are sitting on the PCI slots:
secure the cooler with the nuts making sure you just hand tighten them. the back bracket isn't rigid. it works like a spring so tightening the screws too much would bend the card -thus damaging it.
next I used the original top cover of the cooler to draw a smaller one that can fit over the original litle fan just hitting the base of the SI-97 . it still can channel some air on the ram and also on the base of the SI-97. I used the seethrough cover of the zalman OP-1
next I installed the Zalman fan (which I chose for being slim and very quiet, also for having a little power splitter with 2 5V and 2 12V dongles)
I had to bend the wire fasrtener of the SI-97 because it was made for a standard 9 or 8cm fan and wasn't exactly matching the zalman.
then I connected the two 5V connectors to the zalman and the little original noisy cooler, which now running on just 5V, became noiseless
so here is a couple of pics of the ready cooling monster
as you can see here there is barelly any space left above my sound card
this is how it looks overall in my rig:
after I was ready I checked the temps again at the same OC of 425/1100 (this time I had the new official 81.85 drivers. the new drivers raised my score to 5799p. in 3dmark05)
my idle temps went down to 26.5C !
the full load temp went down to 40.1C !
now to more OC. went up to 435/1100. my computer froze!
no matter what I tried, nothing worked. after a long time of reinstalling drivers, trying all kinds of troubleshooting and reading info on the net, I discovered the problem! it was my PSU. nothing wrong with it, just doesn't have enough juice for the combination of my prescott 3.2 @ 3.5ghz + the card exceeding at ultra speeds. I read that the prescott itself is using about 200W and the real ultra needs about 275W! my chieftec is only 420W. I took out one of my ram sticks, disconnected the dvd rom and the second HDD. tried again: went up to 444/1100 with little artifacts and got 6012p. in 3dmark05!
I past the 6K with only 512MB of ram running in single channel! I comnnected the second HDD back and checked again with the same setting : 5985 points. disconnected the HDD again : 6012p. again! so it seems I'm PSU limited
I also changed the 3D volts to 1.4V and this was a disaster. my card would freeze even at 370mhz of GPU! and its not the temperatures as you see. now I have a dilemma: I'm suppose to put together a new rig with the P4 M that I have won, so I didn't want to buy a new PSU for my present computer, which I intend to sell. on the other hand I'm curious how far could my 6800LE go with this kind of cooling...
even like this I wa able to more then double my cards performance: to be exact- 207% of the original score, at the same time the excruciating noise from the original fan is gone and my load temps are down 19 degrees celsius! the mod is very easy to do, pretty cheap (considering the performance (the SI-97 costs close to the price of arctic silencer5 which besides making the card silent isn't better then the reference cooler) so I'm pretty happy with the results