Saturday, 28 March 2009

Maintaining and upgrading my desktop PC for photography – Part 2: Making the PC quieter and improving CPU performance

Having done some simple software system maintenance which successfully boosted the system’s performance I decided that before doing much in the way of hardware improvements I would like to make the PC quieter; which led me down another speed enhancing route that I had not foreseen.

I watched a series of videos on making a PC quieter on Quiet PC’s web site; go - here - if you would like to watch them.

These videos did several things; they made me much more confident about digging around in the guts of my PC and gave me a whole lot of clues as to how to quieten my PC. Essentially most of the noise from a PC comes from the various cooling fans used on the case, CPU, graphics card, power supply etc etc.

One tip from the videos was that there is usually a switch in the BIOS that can turn on a CPU fan control circuit which will vary the fan speed (and thus noise) with CPU temperature. After a bit of delving I found the control in my BIOS and turned it on. This certainly worked and every time I turned on the PC from then on the fan started out at full (noisy) tilt and backed off after a few seconds – which initially made me think the PC had died. This made the system much quieter, but highlighted that the single 80mm case fan was pretty noisy.

To try to see how much work the fans were doing I found a really useful free utility called “SpeedFan” which essentially reads all sorts of useful information on temperature, fan speed and power supply voltages which it displays in real time. If you want to have a look at it and download a copy then go – here - where you can also make a donation to support Alfredo Milani Comparetti’s work. Usefully SpeedFan puts a digital readout of the CPU temperature in Window's system tray so that it is easy to keep an eye on it while running other programmes.

With the variable CPU fan speed function turned on I became aware that it was varying quite a lot – and the variable noise levels were almost worse than the previous flat out fan noise, but it did tell me whenever the CPU was getting hot. This audible warning combined with SpeedFan’s output made me aware that the CPU was getting pretty hot during intensive Lightroom and Photoshop work and that the hot CPU periods seemed to coincide with some of the sudden unexplained slow downs I was still experiencing with Lightroom.

The screen shot below shows that the CPU was regularly getting up to around 60°C and was usually around 47-50°C when doing anything much. It also shows that my power supply voltages are nearly out of spec, which might also contribute to erratic performance.

I read that Intel P4 CPUs don’t burn out when the get too hot – they just slow down until they cool down again and I guessed that this might be happening inside my machine.

So to reduce the noise and to improve the CPU’s cooling I decided to change the CPU cooler fan from the noisy Foxconn one that came with it for an Arctic Cooling Freezer 7 Pro, using Arctic Silver Ceramique heatsink compound and Arctic Silver’s Arcticlean cleaner to remover the old thermal paste from the CPU and prepare it for the new installation. I also bought three Hiper 80mm case fans, along with silicone Acousti mounts to reduce the transmission of fan vibrations to the case. These replaced the single input fan and added in two output fans which the case had the fittings for, but were not installed before – thus drawing more hot air out of the case. All of this cost about £40 from eBuyer and eBay.

With a huge amount of trepidation I swapped over the CPU cooler – it was much easier than I thought although I am not convinced that I have got the attachment clips in place totally correctly. The clips rotate and I could not find a positive click stop to tell me when they were tightened properly, but it seems to work.

The photos below show the old Foxconn CPU cooler (along with the original set up before I started any of this work and the empty fan installation locations) and the new Freezer 7 Pro cooler and exhaust fans installed (along with various other modifications that I will be talking about in later postings).

What was the result?
The whole PC is now much quieter, but I think I can make it quieter still by reducing the voltage to the case fans a little, which reputedly reduces the noise a lot without reducing the airflow much. I plan to use some Zalman Fanmate variable fan speed controllers to achieve this.

More crucially, according to SpeedFan, the CPU now operates at around 40-44°C most of the time and does not go much above 50°C when running intensive photo processing work – so it looks as if the new CPU cooler is much quieter and, along with the increased case cooling from the extra fans, is reducing the CPU temperature by 7-10°C. This does seem to reduce the unexplained slow downs while using Lightroom further, but not quite completely.

All in all I am happy with these modifications – the PC is much more pleasant to live with and works better.

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