Man, sorry if I understood wrong, but are you recycling an i7 920 processor to put in place an i7 980X ?

Wow ! I guess that you will get a lot of interested people to make a deal with your i7 920 (retired) !

Thank's Marc.
I forgot to mention. But I am also looking to smallest possible frame, mini or micro tower for space reasons. So the motherboard should be of micro-atx type.
In micro-atx format the only 1366 socket board I found is the Asus ROG Rampage II - GENE board. The best price I found was at PCTOP at 281.-CHF which is quite expensive.

Another motherboard is DFI LANPARTY JR X58-T3H6.

With the current projects you can definitely get by with 4GB of RAM. I've got 3 running with 4GB and haven't had any problems.

To cut down on power, heat, and cost, you could always use USB thumb drives. You can use the Dotsch/Linux distribution for a quick start:
http://www.dotsch.de/boinc/Dotsch_UX.html

For case ideas, try the power search at NewEgg. Even though you probably won't order from them, you can pick every detail of the case you're trying to find to narrow down your list and see what other people are saying about them.
http://www.newegg.com/Product/PowerSearch.asp...Category=7&GASearch=3

I looked at low cost mini cases, but the really cheap ones like 30 or 40 dollars are really bad quality wise. They lack good quality, silent fans, or they just have no fans at all. I also found a 79 dollar box with 350 Watt power supply included and no fan. I use to open the boxes at the store and look at the products. Those with power supply were a disaster in terms of cabling quality, connectors and power rating.

So now I have a problem with the definition of cheapest solution. I decided that it has to be according my personal engineering quality standards. Finally it cannot be just the cheapest. After all the unit will have to run 24/7 for a long time. It has to be of the fire and forget type. And inside is running an i7 950 overclocked. So the power supply must be able to handle it well and with low loss, otherwise the low acquisition cost will end into a high consumption cost. This means the power supply has to be certified 80 plus. Unfortunately there is a big price difference between a certified box and a standard one.

Finally I went for a Silverstone black mini box, a power supply from Cooler Master Silent Pro series. As for the motherboard after some thoughts I had difficulties to switch to another brand than Asus. I am so used to their motherboards and never, never had any problem. I know them by hart, I can assemble them blindfolded, and now perfectly their bioses. This means the Gene was the only one available solution at hand for me.

So we have the following components:

Silverstone Box Temjin Series Black with one front and one back fan. Fans are good quality silent fans on ball bearings.
Dimensions are: Width 195mm, Height 381mm, Depth 378mm. A really very compact volume, the smallest machine I ever built. Cost is 117 CHF

Cooler Master Silent Pro 600W. 134 CHF

Motherboard ASUS micro atx Gene. 281 CHF

Harddisk 500 GB Western Digital 7200rpm Sata300. 59 CHF

DVD Reader Lite On. 24 CHF

Video Board ASUS GT220 (1GB DDR3 version). 104 CHF

CPU Intel i7 950 (0 cost)
CPU Cooler Intel new gen 980X cooler (0 cost)
Memory Patriot 4GB DDR3 RAM 1600 Mhz 8-8-8-24 (0 cost)

The cost of this mini box fully equipped is 719 CHF or 665 US$

The problem was to fit everything inside. Not easy but the Silverstone has a well thought removable backplate supporting the motherboard. Just one screw holds everything and you can remove the backplate with the motherboard on it.
You can only insert two memory modules. The space of the third module slot, is eaten up by the DVD reader and harddisk.
Finally I got a small very compact unit that runs the i7 950 at 3.5 Ghz, for 665 US$. Core temps run at 70-75 deg. The New Intel cooler does a decent job but is a little noisy.
This new machine is now online since a few hours and has started crunching for WCG full steam. It is my first satellite to my planetary system and the name is Phobos, satellite of Mars. You immediately hinted that Deimos will come in a near future if I am satisfied with this new design.

Not yet bono vox. Let's wait until WCG becomes GPU compatible.