Yes, a silent system afterall!
I did the psu-mod to the silentium t2. That is to say i cut the wires from the psu to the psu-fans and the case-fans and soldered new connectors to
them. Male-connectors to the fans; female connectors to the psu-feedwires.
It's not necessary to dismount the psu completely. Only pulling the outside rubber-bands of the harddisc-silencer gives enough room to cut the wires to the psu-fans and put new connectors on them.
As a second step i placed a 3.5' fan-controller in the middle 3.5' bay. It's an enermax 2-channel controller with 2 fan-wires and 2 temp-sensors.
One of the sensors i stuck inside the psu to feel it's outstream airtemp. The other tempsensor was mounted above the motherboard and measures the temp of the air flowing into the top silentium case-fans.
The third step was the final silencing of the second harddrive, that is mounted in the lower 3.5' bay. I fixed rubberstrips to the bottom-edges of
the drive and to the sides and then placed the drive in the bay. I secured the drive with a piece of 'button-elastic' and a zip-tie.
As a last step i paid much more attention to cable-management now. I managed to get the main 20-lead power cable out of the airflow to the
psu-fans. Additional power-lines are now routed differently to the right of the t2-silencer-box. The sata-cables are zip-tied together and are also
for the most part not in the direct airflow-path. The wide ide-cables to the dvd-writer and the floppy-drive were mainly hidden behind the 3.5' bay and on top of the dvd-writer.
At the moment the silentium psu- and case-fans are connected to the fan-controller through wires containing 3 diodes (you can see them in the last
picture) giving a voltage-drop of about 1.8 volts on top of the voltage-drop the fan-controller provides. Both fan-speeds are turned down; the
case-fans at the lowest speed. The psu-fans a bit higher. The silentium fans don't give a tach-signal, but i estimate the psu-fans are running now
at about 800 rpm at the most and the case-fans at about 600 rpm. The 2 push-fans also run at about 800 rpm.
The machine is silent now; not quiet, just silent. On a distance of 3 metres away the computer can no longer be heard. These mods had a big
influence on the temps of the various components.
Idle at intake-temp 15c:
case top: 25
psu out: 35
Both the gpu and the harddrives run hotter now as compared to the default silentium setup. The gpu 10C and the drives about 6 to 7 C. Should be no problem. The psu also is running hotter than before. One can feel pretty warm air coming out of the vents at the bottom of the case. I did a test with 2 instances of cpu-burn for 30 minutes and that gave the following temps:
case top: 30
psu out: 40
I'm not sure if the machine is thermally stable during heavy gaming, but i don't do that. If i would do that occasionally i could turn up the
fanspeeds. For the time being i'm going to see how the machine behaves during different loads and different intake (room) temps. Maybe i'll
replace the 2 push-fans by larger 92 mm ones and have them controlled by the fan-controller too. They are now controlled by the mobo on fan-header cha1. Another setup might be connecting the fans to the psu again through the diode-wires to get some sort of automatic temp-dependent behaviour back. The soldered fan-connectors give all freedom now to experiment.
The second harddisc in the lower bay is completely silent now. No more hum; not even with the vastly reduced fanspeeds.
Curious about any comments and suggestions!
And now for the pictures:
Silentium harddrive silencer partly dismounted
New connectors to silentium fans and psu-wires (male for fans; female for psu-feedwires
Rubber strips to be mounted on harddrive
Rubber strips stuck to harddrive
Harddrive with rubberstrips mounted in lower 3.5' silentium bay with elastic and zip-tie
Temp-sensor of fan-controller stuck into psu to feel psu-out-temp
Enermax 2-channel fan-controller between floppy and silenced harddrive
Total view of system; fanwires still a bit messy and experimental; improved cablemanagement