Mick - you should note that that PSU is not 80 plus certifed, and the 15dba is only at low loads. Also note that it doesn't have overpower protection, which could be relevant in a PC that is going to be running 100% most of the time.

You're right. Afaik, PSU selection is a minefield. The only consistent advice that I've come across is not to spend too little money.

Couldn't agree more. Spend as much as you can afford (and avoid no-name PSUs like the plague), especially in a highly stressed environment like this. I think it's going to be a tough ask to combine folding@home with a quiet PC. I'm not sure the PSU is going to be the problem noise-wise; I would expect the CPU fan to be the major culprit.

I'm certainly willing to fork out a bit more on the PSU. Could you recommend some to choose from? Looks like I could get away with 400/450 Watt. I have the option later on to put an extra fan in the case, or even (if I'm brave enough) a new heat sink on the CPU.

I fully understand my PC will be operating at 100%. It's basically what it's for - to spare my (our!) iMac.

On my Intel iMac, in Activity Monitor, I see figures like 197% for FahCore_a3.exe which is the name of the Folding @ Home client I run. That's when little else is running, of course.
On my eventual PC I would expect corresponding values of 397% for Fah wouldn't I, considering the Intel Core i7-2600k has four cores?

I understand your comment re F@H/quietness being a tough ask, but at the moment the CPU Core temps are 72ºC on my iMac and it's quiet enough so as to be quite unobtrusive. The HD Drive Bay temp is 47ºC.

In reply to a post by ichatergosum:

at the moment the CPU Core temps are 72ºC on my iMac and it's quiet enough so as to be quite unobtrusive. The HD Drive Bay temp is 47ºC.

Which version of F@H are you running? I looked at it but it appears V7 isn't OS X ready yet.

My iMac is idle a lot of the time, and it might be nice to give it something useful to do

I've got the 6.29.3 client - I went to the middle button here and downloaded the middle option:

[email protected]
Mac OS X 10.5+ Intel 32/64-bit SMP Installer

Thanks, I'll investigate a bit further than I did last time.

Interesting that you should say that.
I also investigated it, some time ago, and got precisely nowhere. What spurred me on this time around was a Horizon programme shown on the 9th of April to do with the work of The Royal Marsden and the Institute Of Cancer Research. It followed the progress of three cancer patients and their treatments, which were eventually successful. The programme is on YouTube, in its entirety.
At one point, about 43 minutes into the programme, there was a huge screen with a 3D model of a protein which could be rotated onscreen to have different perspectives. It's the cavities in these structures that they're interested in with regard to possible drug design. That was the moment I decided that I would get f@H up and running, finally. I've had it up and running since shortly after the 9th of April.

(You can probably tell that I can be a Folding @ Home bore.)

A couple of other points to consider that are on my mind (and I have not run FAH for a long time) are:

Don't GPUs (the graphics cards) play a far more important role in processing protein folding software tasks as above?

And, have you considered the Playstation 3?

I really don't know anything about all this as it currently stands but I can see there are whole sections of FAQs devoted to the subjects at FAH:

http://folding.stanford.edu/English/FAQ

Also, there are a great many Folding Forums and these have a lot of dedicated people who can give some expert up to date advice. I think it should be okay to give a link here to Bit Tech: http://forums.bit-tech.net/forumdisplay.php?f=111, they have one such forum and the advantage is their site is totally geared up to computing, including 'folding' and building custom specs, choosing and sourcing components. I think you should not overlook the role of the graphics card but maybe things have moved on with the latest crop of multi-core central processors?

Lastly, you can get SSDs relatively cheaply these days as prices have fallen considerably in the past month. A Crucial M4 128GB SSD is not a bad choice for price/performance: £87 example at Amazon (be sure to update firmware first though). Oh, and my hunch is that you should be able to buy a relatively small case and modest system spec and still have very good Folding performance without needing to worry too much about super efficient cooling requirements above and beyond a few fans. It just depends on the hardware and how hard you intend to run it and this is why you need to read up on other people's experience in building this niche quiet and high performance design really - fans and heatsinks can be replaced but that's a hassle you can avoid if reading about other people's experience beforehand.

Thanks for your post and the links, especially the bit-tech forums which are new to me.
There is a huge amount to read on the F@H website. I've been reading and re-reading stuff for the past couple of months, and asking questions on their forums. Quite a bit of the info is out of date, I've found, but gives a perspective on things in general. Even more is way over my head.

I decided the CPU route over the GPU route on grounds of cost. There are plenty of WUs to run on CPUs and for the time being I'm happy with that. At present the WUs I'm getting are helping to study how influenza viruses recognise and infect cells. It's early days for me yet with F@H. I might expand my horizons in time.

As well as wanting to contribute to the F@H project, I also want to build my own PC just out of plain old curiosity. I've read about the PS3 which has made huge contributions , but I'm not tempted (must ... resist ...).

Edited by deleted (Sun 17-Jun-12 12:21:43)