Leadtek 6800GT/Ultra/NU silent mod
Posted: Thu Jun 02, 2005 10:16 am
I've created an interesting mod to silence leadtek 6800 based graphics cards. They come with a custom copper cooler, which is called air-surround, that uses a 50mm fan. It's quieter than the standard 6800 cooler, but still loud if you care about silent computing. The main thing is it being rather large and solid copper, it's got excellent possibilities.
with this cooler at stock, my 6800GT (@ultra speeds) runs about 60c idle, and 85c load. The cpuburn equivalent for loading your graphics card is generally agreed to be rthdribl - http://www.daionet.gr.jp/~masa/rthdribl/#Download.
Now for the mod. Firstly i junked the horribly restrictive air filter over the fan. This improved things a little, then i disconnected the fan and put a 60mm fan over the air filter hole at 7v, this was much quieter, but not even close to perceptibly silent.
In the photo you can see there's a plastic shroud, intended to guide the fan's air flow over the copper cooler beneath it. To remove the shroud, you have to remove the heatsink, as it's screwed on from the underneath of the heatsink. I thought removing the shroud would be wise as it limits the amount of air you can get to the heatsink under it, you can't go bigger than 60mm.
While i was doing that, i took a look at the thermal compound on the gpu, it appears to be silver based, but i cleaned it off and put some fresh AS5 on there, about a rice grain sized blob, as the NV40 uses a heatspreader.
With the shroud gone, the fan options are a lot better, with some experimenting i found frameless fans worked quiter and cooler, it's a wide heatsink so the frameless fans get more air across the heatsink.
The upper size limit for a fan is 92mm, due to the width of the card itself. Unfortunately the only 92mm fan i have to hand at the moment has a dodgy bearing and is clicky. however i still tested with the 92mm fan, as well as an 80mm.
it seems 5v to the fan is enough for cooling the card. The actual results were:
80mm frameless fan @ 5v - idle 55c, load 79c.
92mm frameless fan @ 5v - idle 53c, load 74c.
That's with a closed pc case too, after leaving rthdribl for half an hour. I did briefly test with 7v on the fans, but fan whir became perceptible, and turbulent noise also appeared, probably due to the many fins on the heatsink. At 7v you can decrease temps by about 2-3c.
For now i'm running with the 80mm fan on it, frameless, and only 5v, and it is completely silent. Temperature is also down from stock cooling by about 5-6c. It's win-win.
I don't have a proper digital camera, this is taken on my SE mobile phone and so a bit blurry, however it gives an idea of the setup and the differences from the stock cooling.
I'm really pleased with this mod, it's quite amazing to have such a powerful card run silently and relatively cool with such little effort.
with this cooler at stock, my 6800GT (@ultra speeds) runs about 60c idle, and 85c load. The cpuburn equivalent for loading your graphics card is generally agreed to be rthdribl - http://www.daionet.gr.jp/~masa/rthdribl/#Download.
Now for the mod. Firstly i junked the horribly restrictive air filter over the fan. This improved things a little, then i disconnected the fan and put a 60mm fan over the air filter hole at 7v, this was much quieter, but not even close to perceptibly silent.
In the photo you can see there's a plastic shroud, intended to guide the fan's air flow over the copper cooler beneath it. To remove the shroud, you have to remove the heatsink, as it's screwed on from the underneath of the heatsink. I thought removing the shroud would be wise as it limits the amount of air you can get to the heatsink under it, you can't go bigger than 60mm.
While i was doing that, i took a look at the thermal compound on the gpu, it appears to be silver based, but i cleaned it off and put some fresh AS5 on there, about a rice grain sized blob, as the NV40 uses a heatspreader.
With the shroud gone, the fan options are a lot better, with some experimenting i found frameless fans worked quiter and cooler, it's a wide heatsink so the frameless fans get more air across the heatsink.
The upper size limit for a fan is 92mm, due to the width of the card itself. Unfortunately the only 92mm fan i have to hand at the moment has a dodgy bearing and is clicky. however i still tested with the 92mm fan, as well as an 80mm.
it seems 5v to the fan is enough for cooling the card. The actual results were:
80mm frameless fan @ 5v - idle 55c, load 79c.
92mm frameless fan @ 5v - idle 53c, load 74c.
That's with a closed pc case too, after leaving rthdribl for half an hour. I did briefly test with 7v on the fans, but fan whir became perceptible, and turbulent noise also appeared, probably due to the many fins on the heatsink. At 7v you can decrease temps by about 2-3c.
For now i'm running with the 80mm fan on it, frameless, and only 5v, and it is completely silent. Temperature is also down from stock cooling by about 5-6c. It's win-win.
I don't have a proper digital camera, this is taken on my SE mobile phone and so a bit blurry, however it gives an idea of the setup and the differences from the stock cooling.
I'm really pleased with this mod, it's quite amazing to have such a powerful card run silently and relatively cool with such little effort.