I have a physical disability that sometimes keeps me in bed most of the day.
As a result, I recently decided to build a PC for use from bed. Given that
it is likely to be my primary use PC, I wanted something with a little
power. I decided on an Intel D875PBZ (Bonanza) motherboard with a 2.6 GHz
Hyper Threading P4 (800 MHz FSB), 512MB PC3200 DDR, 120GB Maxtor ATA/133
7200 RPM 8MB cache hard drive. For sound I went with an SB Audigy 2, and for
video I went with an ATI built Radeon 9700 PRO 128MB.

The flip side is, being a mere 18" away from my pillows, I also wanted to
build a QUIET PC - hopefully the quietest PC I had ever built, despite its
muscular nature. Accordingly, I built the system in a Lian Li PC-6070 case
which comes with two oversize, low-speed front case intake fans, an oversize
low-speed rear case exhaust fan, sound insulation material on the sides and
top, and (to help with CD/DVD drive noise) a thick aluminum door on the
front with "weather-stripping" to prevent sound leaks. I installed an
Enermax Whisper power supply with a manually controlled exhaust fan (which I
run at lowest speed). The Maxtor hard drive has fluid dynamic bearings, and
I purchased my DVD and CD recorders with an eye to quiet as well.

Finally, and probably most significantly sound-wise, I replaced the "stock"
CPU and GPU fan/heatsink assemblies. Using Arctic Silver 3, I installed a
Zalman CNPS7000-Cu - a truly wonderful heatsink. I run the fan on the Zalman
at it lowest speed, and it still keeps my processor five to ten degrees
cooler than the OEM fan/heatsink.

On the 9700 PRO, once again using Arctic Silver 3, I installed a Zalman
ZM80A-HP. I believe that I did a clean, competent installation of the
ZM80A-HP, but I remain a little concerned about it. For instance, the
instructions for the Arctic Silver 3 compound stresses the fact that the
thinnest layer of compound that actually "fills the gap" gives the best
cooling performance. On the other hand, the instructions for the ZM80A-HP
warn that, due to video card/GPU design, there may be a problem with the
heat sink transfer block seating against the GPU, and that you may need a
thick layer of heat transfer compound.

As best I could tell, on my Radeon 9700 PRO the heat sink transfer block
seated cleanly against the surface of the GPU, and for that reason I tried
to keep the transfer compound layer fairly thin. I am concerned, however,
that the GPU may be running hotter than it should be.

According to the Intel Active Monitor software, my processor is running
104F/40C , the ambient temperature sensor integrated in the hardware
monitoring ASIC reports 100F/38C and the remote ambient temperature sensor
reports 99F/37C. Both of these sensors are mounted on the motherboard,
fairly close to the processor socket. In addition, I have a Lian-Li T-3,
which has two thermal sensors that can be placed wherever the installer
wants, and two LCD displays. I have one of the thermal sensors positioned in
the middle of the intake airflow "after" the hard drives which reports
88F/31C. The other thermal sensor I positioned so that it resting on the
side of the GPU heat sink transfer block - NOT between the transfer block
and the GPU - and this is the one that worries me. Not running any 3D
applications whatsoever, this sensor reports between 125F/52C and 135F/57C.
This is just running Internet Explorer, Outlook Express, Word and other
productivity apps on the Windows XP desktop.

This seems pretty hot to me, but I am not sure what kind of temperatures the
9700 PRO GPU is intended to operate at. I am not currently overclocking
either the system or the video card, and I have no driving desire to do so.
On the other hand, I am going to start loading up some 3D games before
long - and I expect that exercising the 3D capabilities of the GPU will
cause it to run even hotter - right?

I haven't seen any problems with the display so far, but I have had one
"blue screen" that reported that the video driver was in an infinite loop -
something I thought might just be caused by an overheating GPU.

I know that I am getting - at best - an estimate of the temperature of the
GPU heat sink - the GPU itself may be running much hotter. Is there some
good way to tell how hot the GPU on an 9700 PRO is running? How hot is it
safe for this GPU to run?

Does anyone else have experience running the Zalman ZM80A-HP on a 9700 PRO?
Will I absolutely need to mount a fan to blow on the ZM80A-HP in order to
keep the GPU cool enough once I start playing games? How do over-clockers
determine if their GPUs are getting too hot - just wait for the card to
"fall over"? Is running this hot going to shorten the live of my video card?

Thanks for any and all information. This is the first time I have done any
"modding" - in the past I always just put the parts together and powered up
the system. I have to say, I LOVE this PC. It runs as quiet as a whisper -
sometimes I have to check the lights to see if the system is running or in
S3 standby!