In case someone reads this... Finally got around to ordering the parts:
Biostar G31-M7 TE
2x2GB DDR2-800 mushkin CL5
Intel DC E6300
Scythe Ninja mini Rev.B
Club3D Radeon HD5770 1GB
Accelero S1 rev.2
1TB SpinPoint F3 HD103SJ
BE Quiet L7 350W
CoolerMaster MegaFlow 20cm
So, obviously this is hardly a high-power build, but I wasn't keen on spending much.
Will overclock the CPU a bit, but with moderate voltages.
About the fan... the previous one, (22cm Bzerk) produced a high-pitched "ringing" noise,
which to some extent persisted even below 5V. The Megaflow at 5V is practically inaudible
to me (tested with 5V brick) Putting the ear next to the hub reveals a low humming sound,
then again my ears will be elsewhere when I use the computer. Obviusly it produces less
airflow, but for this half-open case design it should be enough. If not, 7V may work.
The PSU is the cheapest bronze-rated I could find with enough connectors. The german site
Technic3d called it inaudible even under full load, but this is of course false. At idle
(with no other sources of noise connected) it is far from noisy, but not silent either.
Unfortunately I discovered that my case transfers vibrations really well, even creating
resonance, which is not what I intended. So the BeQuiet while reasonably quiet on its own
makes the case noisy. This is indeed a pity, especially considering how quiet the case fan
is, and how well it probably would cool a passive PSU. How to suspend the PSU in such a
small available space? Perhaps I should have bought that Fusion 550R after all, unplugging
the fan would have been so much easier on that one. Ah well. For now, some thin foam around
the PSU and under the case lid reduces the noise somewhat.
The F3 is not annoyingly loud. It does produce a typical hizzing sound which is clearly
audible up close but fades away quickly. If the hizzing ever becomes a problem, I suppose
I could make a tiny foambox to hold it. As for vibration, there's not enough room in the
case for a proper horizontal suspension. At present it's resting on foam on top of the PSU,
secured by slightly elastic string. Mounted this way, vibration seems negligible compared
to what the PSU produces. Hard to tell though, because it won't spin down for more than a
few seconds.
The 5770 is obviously the loudest part at present. Its custom fan is quite noisy at default
speeds. Turning it down to the minimum 20% makes it bearable, and by then from about 3m away
most of the noise drowns in ambience. But while gaming 20% is not enough. Fortunately I have
an S1 waiting for the card.
Of course, installation of the S1 turned out a bit complicated. The heatsinks was the easy part,
all the chips were already clean so thee tape stuck easily. The cooler however needed some work.
First of all the mounting area on the card was only 5cm square (42mm hole distance), too small
for the S1 base. That was easy to fix though, just remove the plastic and cut the corners on the
mounting bracket. After that 19 of the fins on the back needed some cutting. Luckily, the Club3d
card doesn't have any dual connectors, just a single backplate with 3 connectors. So after some
fiddling with the distances and the screws the card was ready for testing. Or so I thought.
Oh no, 50°C at idle passive! Oh no, why did I start Furmark - it's already up at 110!
Better shut
down and add a fan. Booting up again. Oh no, Windows displays no picture! Shut down. Reboot.
Oh no, Windows enters a 30 min uninterruptible recover because I shut down with the power button!
Shut down. Reboot. Oh no, Windows displays no picture! Better give up and retry tomorrow.
However, after reinstalling with shorter spacers and less thermal paste, the S1 worked fine.
Temps (°C) at idle / load (Furmark 1.8.0 default settings)
Stock fan (auto speed) 35 73
First accelero mount 48 110 (aborted!)
Second accelero mount 35 85 (10 min)
+ 80 mm Ninja fan 32 66 (20 min)
+ 140 mm Revoltec AirGuard 31 59 (20 min)
The fans listed above were centered over the GPU and blowing upwards, away from the card.
They were connected to an external 12 brick through a resistor. The Revoltec was a bit loud
but probably less than the stock fan at idle. Since then I have put some foam between the S1
and the Revoltec fan, and attached it to the 2pin fan connector on the card. It is now quiet
at idle (fan speed at 85%), and reasonably quiet when spinning at 100%. Can't say for sure
how much voltage the card produces at 100%, best guess is around 8V. MSI Afterburner is used
for automatic fan control, and the GPU rarely goes above 55°C during gaming.
Overall I'm satisfied with the noise level of this build. Though to be fair, it is currently
hidden away next to the sofa, which dampens the noise somewhat. In practice it is barely
audible over the ambience in the quiet room. With headphones on, the reciever buzz is louder.
With any sound playing at low volume, no noise can be heard. Of course, noise level is very
subjective, and I doubt any hardcore SPCR member would call it silent.
As for the temps, they are neither great nor terrible. The gpu temps should be ok, since they
are a lot better than with the loud stock cooler. The cpu is semipassively cooled by the large
intake fan blowing through the Mini Ninja. It idles exactly at body temperature, while Prime95
brings it up to 55°C. Although it runs at 3.34GHz (1.1375V, 10x FID) both temps are higher than
expected. The silent front fan running at 5V may provide too little airflow (or air velocity),
but I may also have used too much paste during installation. However, during typical load it
rarely reaches 45°C, which is acceptable.
The northbridge (FSB at 334MHz) is a different matter. Idle temp at 35°C is fine, but Prime95
brings it up to 65°C which is not healthy. Even at typical load it often reaches 55°C. The tiny
heatsink, hidden behind the DIMMs, probably recieves very little airflow. I tried during the
build to direct more air towards it with some cardboard, but couldn't notice any difference
at the time, may have to try again. Installing a taller heatsink (like a Zalman ZM-NBF47)
should otherwise solve the problem.
Meanwhile the Samsung F3 at 27°C is possibly a bit too cool. But I have not foamed it yet.
Pictures will come later, if anyone is interested.