Ive now fitted the new bits to cool my PC, needless to say, I had a few issues. The first proved to be unfounded, which was the size of the Arctic Cooling Pro 7 Rev. 2. Its big, really big and looked, at first glance, too big to go in the Thermaltake T4 case but that proved to be a momentary panic and its now in place and humming along. I havent got quite the cooling I was hoping for though, but I had no information which would suggest what I should get, I was just hoping for a 10C reduction. Its turned out to be 5C, the processor was previously running at 61C and is now down to 55-56C at 100% load, 44-45C at around 50% load and 34C idling at 8-11% load. All of this happens without any increased noise from the PWM fan on the Pro 7. Im not monitoring the fan speed so I dont know if the RPM increases, but if it does, it does so without noticeable increase in sound.
The Pro 7 comes with two brackets to be used with AM3 sockets and not having done this sort of thing before, they were a bit of a concern when it came to fitting the Pro 7. The brackets hook under the lugs on the mainboard, at the side of the CPU mount and then, after the fan on the Pro 7 has been removed, need to be screwed to the corresponding mounting on the Pro 7. So the question for me was, just how tightly do I screw them down? No definitive answer to this, they could be tighter, there remains a small gap between the two parts of the bracket which could be closed but it did feel like I was putting a fair amount of pressure on the screws to get it where it is and have left it with the small gap for the time being.
The other issue I had was with the mounting of the Zalman ZM-SF3 120mm fan, not a problem with the fan itself, just that I couldnt mount it where I planned to. Initially I was ready to blame MESH for having mounted the microATX board too high in the case, but having looked at it more closely, they had no choice. There are various fixed mounting points within the case but in order to line up the USB, network, sound and video outputs with the opening in the back of the case, the upmost mounting points have to be used. And if this is done, then the two grilles in the top of the case, threaded for 120mm fans are useless for 25mm deep fans. One is fouled by the plug in the 12V ATX header and the other by the RAM modules. I dont know if the layout of the mainboard is unique to Asus but the combination of Thermaltake T4 case and Asus M4A78LT-M ensures that standard fans cannot be mounted in the top of the case. After thinking about asking QuietPC.com to take the Zalman fan back and swap it for a half height fan I decided I would try it on the side of the case and have it push air in, towards the Pro 7 and CPU and, after another moment where I thought I would be unable to close the case due to the fan catching on the PSU or the graphics card, it seems to be working well. The Zalman is very quiet. Im currently using an RC56 resistor to slow both the Zalman and the existing case fan to 60% of their usual speed, but I think I may just put the resistor on the old fan and see how the Zalman sounds at full chat.
My PC is now considerably quieter and the CPU quite a bit cooler, still to see how much of a dust trap the Pro 7 proves to be, which is where this all started, but even if it proves to be just as attractive to dust as the stock cooler, its running the CPU cooler and quieter and can be cleaned in situ. Certainly its £30 I would have preferred not to have to spend on a 2 month old machine but it does look like the modifications have been effective.