Annoying fan noises in mini itx HTPC

[HipHoper]

Hello !!

I bought this really nice and small Mini-Itx case :

http://www.plonter.com/detail.tmpl?s...76336&lang=heb

And bought an intel mini itx G41 based board for this case.

Now...The case's fan are quite quiet, But although I can put an regular 775 cpu fan, It seems to be quite noisey. All intel boards I used so far (g31 based mostly) have this thing that spin the cpu fan to high RPM, And I could'nt find a workaround this (Bios update, Bios setting doesn't change it).
I used Intel 2180 cpu with this babe.
What I did is replaced rear fan with quite quiet glacialtech 80mm fan (This is maximum fan size for rear of the case),And connected it's 3 pins to the case fan connector which spins the cpu at a lower RPM rate than the CPU fan connector, And built a cartoon tunnel than drive out air out of the case.
Temp looks fine when not under load (Around 40 deg cel.), But it goes to about 55 when playing HD movie.....
I tried to made the glacial work with 5 Volts, Although it's quiet, It doesn't cool well (Around 46 deg. cel when not under load).
I don't know right now how to improve cooling/noise ratio.
I think of getting some silent cpu cooler and making the glacial tech rear case fan to work at 5 volts again....Any suggestions ?

[Platypus]

There's really only a few possibilities, since the operating temperature will be determined by the airflow.

The E2180 is a 65W CPU, so depending on how hard its working, the CPU cooler has to extract up to this much heat, and how well it does this will govern the CPU temp. A passive cooler will be silent, but is dependent on case airflow for heat removal, so the rear fan will do all the work (ie will need to be full speed) and the CPU temp may be higher than with a CPU fan.

The most successful way is probably going to be to find a CPU fan that is quiet running, but still gives good airflow.

The next thing I would look at is the CPU utilisation. If the CPU is running at high utilisation to decode a HD movie, and there is a video card slot available, then using one of the low cost passively cooled multimedia accelerator video cards (ATI seems best) could drop CPU utilisation from maybe 85% to around 40% when decoding.

The motherboard would need to implement Speedstep to get best results from this, but I'm not sure which particular Intel boards have this implemented.

[HipHoper]

Thanks plat for the tips. The only available slot is a normal PCI, And I keep it for an internal wifi card i've ordered....
Cpu utilization is above 50% while decoding HD movies. At least it has the X4500 intel chipset, So on one side it saves video card costs, But it make the cpu works harder.
I have several other cpu's (E7400/E6300) that might lower cpu utilization, But I'm afraid that they might run hotter than the 2180, Although I think they're also 65W cpus....

[Platypus]

Then if you're stuck with the onboard video, one of the Core2 CPUs might be better, they're a more efficient CPU, so will probably run cooler.

The E6300 particularly has a case temp specification at 65W of 61.4°C, compared with around 73° to 74° for the other two.

[HipHoper]

Great to know about the E6300. I've bought several of these, And it'll be nice to put one into this little beast.
It seems that the main noise comes from the (Cheap me) 80gb old sata hard drive and not from the rear fan (Although it does make some noise too when compared to my antec fusion total silent case), So I might replace the CPU/DRIVE and install an internal wifi card when it arrives.
I'm also considering buying this one, Since I am satisfied with arctic cpu cooler I've bought in the past, They're cheap and totaly silent when in low RPM mode :

http://www.arctic-cooling.com/catalo...h=1_42&mID=259

[HipHoper]

Well.....The E6300 does produce significantly more heat....What I did is bought a silent 1500RPM 80mm fan and put it directly on the CPU heatsink, So it's cool and quiet now (38 deg. Celsius not under load).
I might consider getting the DVD out of the case and buying an hard drive silencer, Since the major noise now is coming from the HD motor....

[Platypus]

Well.....The E6300 does produce significantly more heat...

That's interesting - not what would appear from the specifications. Did you clean off the cooler mounting face and renew the thermal paste for the second CPU?

[HipHoper]

Yes...But I looked deeper into it, And the reason for the excessive heat was the ned Hitachi 250GB hard drive....It went to 47 Degrees....I've put back the 80GB drive and it's less than 40 degrees now....Go figure....I'll try another bigger (500GB) drive and see how it goes....