I do around 1.17 hours on 8 wu's at a time with 2600K @4.7 This figures are with a mix of all projects so not sure if selecting just C4CW would alter that

I will let you do the maths but I am thinking that clock for clock it takes me +50% time to do +100% work units

Win7 64, Giga p67 ud4, ddr3 1600 7 8 7 24. Samsung f3 1TB.

I have a 1.2 hr average per C4CW WU on a 3960X at 4.2 Ghz. But I crunch 12 WU at a time. My performance is measured with the CPU running a mix of projects, C4CW, FAAH, GFAM, DSFL. On a clock per clock basis I would be at 1.14. Your performance per WU is excellent. In terms of number of WU crunched per hour you would be beaten.
Just to check all parameters, can you please tell us the RAM speed you are running and the motherboard model/type, as well as your HD model/type and if it is an SSD. Regarding the WU's do you run only C4CW on that CPU or a project mix.

granno21,

Actually, the old adage is to mix on multicores, so the evidence over years has demonstrated. Exceptions being the light stuff such as what C4CW, HCC, HCMD2, DDDT2 are [of the single threaded projects]. At other grids it was even found that running the same on a quad, for all cores, could turn out to give negative production... 3 cores, 1 idle doing more than 4 at the end of the day. BOINCTasks as a BOINC Manager substitute is the superior tool to monitor efficiencies for *your* hardware. Experiences vary depending on hardware/OS combo's. CEP2 does much better under W7-64 than Linux 64 in dual boot, for me.

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Generally yes, crunch a mix of tasks.
To some extent C4CW might be a bit of an exception (especially if you have a 64bit operating system), and it depends on the CPU (core count, HT or not). On a Quad (say i5-2500k) you could probably get good performance from 3 C4CW tasks, but running 11 out of 12threads on an i7 would not be so smart. It's generally better to run a mix of tasks for many reasons.