Hello all,

Thank you all for your advice. I have done some shopping around in Australia for computers that are going to give me the most cores as number of cores seems to be the main message from the advice that has been provided here.

I started out really cheap for some testing and bench marking with a Dell 1950 from ebay for $130AU. This machine has two Xeon E5410 CPU's (These are quad core with no HT, so 8 cores) and is currently returning on average 33 results per day for the last 13 days. This equates to approx. 25,000 points a day. I also purchased a power meter and for this machine alone, it consumes approx 350w.

I have now ordered a HP Proliant DL380 G7 with two Xeon X5660 CPU's. I will post the results once I have had this machine running for a while.

Thanks again to everyone for their advice, It has provided a great deal of help with my contributions to World Community Grid. This help is really appreciated.

Those machines come with two power supplies (for redundancy purposes.). If you want to lessen the amount of electricity you use, just use one power supply. I have an identical unit and have been running on only one power supply for years with no problem. The other thing you can do is see if you can get a couple of Xeon L54xx chips to replace the E5410's. They use fewer watts.
Edit: This unit is currently running all MCM1 and averaging about 4400 BOINC points per day (30800 WCG). If it was running just the Ebola Vina units it would do about twice that in points (running Linux).
Cheers

There is no question that each succedding generation of chips has become more efficient in terms of work done per watt. I know I spend more on electricity than I would like. However, I try to balance costs versus the benefits of the work being done. That is why I have shut down my most ineffiecient systems.
Cheers

All of my rigs are bare minimum hardware (single stick of ram, no video card, single low power fan, 80+ psu). The e3 and e5 are the best chips I tested, for example the i7-4790k only did 50 points/watt. 90% percent of the cpus I tested including sandy, ivy, haswell deliver the same results you've got, 50-60 ppd/w.

Ok, so i may have gone down the wrong path with the old servers by the sound of it. Thanks for giving me the heads up on the power usage of these servers.

Unfortunately I have already bought these and I will have to use these until I can put some more money together for a more modern cpu like the ones mentioned above. Does anyone know of hand if it possible to get dual socket motherboards for the Xeon E5 2683 (or similar) at a reasonable price? Would this negate any power savings gained by using these CPU's (extra heat and motherboard may use more power than two separate motherboards???).

As for the server I have now, I have taken the advice of fuzzydice555 and Sgt.Joe. I have now removed unnecessary hardware (1 psu, two hdd's, two of four sticks of RAM, Optical Drive, and a raid controller) from the Dell 1950. This has bought the power usage down from 350w to 250w. I have reinstalled my OS to a USB stick.

Still waiting on the new HP from my previous post and will post some details about this when I get it set up.

Thanks again everyone, it is good to have these discussions to get the most we can out of our hardware.