Originally posted by: Jimbob
Hi all thought I had to post pics of the mod I performed on my A8N setup. I'm running 2 x XFX 6800GT's in SLI, 2Gig Crucial Ballistix RAM and a 3500+ clocked up to 2.6Ghz. I can't stand PC noise and have managed to get this beast of an SLI system almost completely silent under my desk. I'm using the ultra quiet Tagan 480Watt PSU, Zalman CNPS7700-CU CPU cooler and 2 x Arctic Cooling Rev.4 nVidia 5 VGA Silencers which some people have asked about above. I also use a 120mm 11dba SilenX rear fan.
Anyway like the rest of you replacing the 8800 rpm screamer fan was a must for me! The Arctic Cooling VGA silencers are superb - not only very quiet but they exhaust the hot air via their plastic encasement directly out of the slot next to each graphics card. This is very important because two 6800GT's create way too much ambient case heat that otherwise you'd have to remove with faster louder case fans.
If I replaced the Northbridge fan with a heatsink the first cards cooling unit would be in the way of it... however I realised if I modded the Arctic cooling unit by removing a piece of the plastic encasement directly above the Northbridge I could fit a larger heatsink. This would also be superb for overclocking as the VGA fan would be spinning air directly onto the larger Norbridge Heatsink AS WELL as the 6800GT chipset! Bonus The 47mm high widely available blue Zalman heatsink was too tall however there is a yellow 32mm high Zalman ZM-NB32J - only available in the UK at
www.quietpc.com that I could find. The blue Coolermaster PAC-P01 also 32mm high would also do the trick however isn't available in the UK.
Here's some pics:-
Zalman ZM-NB32J Heatsink with Arctic Cooling mod
Inside my case from above
It worked perfectly. As expected due to the fact it's now got a heat source under the fan GPU 1 has risen in temperature slightly. However so has GPU 2 and the CPU slightly. Unfortunately at the same time as the mod I also installed noise dampening material blocking some side venting as well as the slower SilenX rear fan, and I'm sure that has added to the temperatures! However it proves that the mod would probably have even less effect if this is all you're changing. The Northbridge is much cooler anyway! Great for overclocking should you wish to push it harder than I have. Here's temperatures monitored through Nvidia drivers and Asus Probe before and after the changes over many days, room temp ranging 20.5-22 degrees:
Before
Average in Windows/Idle
CPU 30
Northbridge 32
GPU1 43
GPU2 38
Highest recorded (Just after playing Halflife 2 and Call of Duty sometimes for 3-4 hours.)
CPU 45
Northbridge 44
GPU1 54
GPU2 45
After
Average in Windows/Idle
CPU 31
Northbridge 28
GPU1 51
GPU2 43
Highest recorded
CPU 45
Northbridge 39
GPU1 66
GPU2 50
Taking the VGA silencer apart was very easy - you can remove the large front plastic cover and hacksaw the exact piece of plastic away before screwing it back onto the back piece of plastic and then re-installing the unit onto the card.
Hope it helps someone.
Jimbob