Comparing mac pro, imac and macbook pro SPEED?

I just did a speed comparison test between my macs. I got a 100mb video file and put it into adobe media encoder cs6 on all macs. I set the memory in the preferences to be the same so they were all set to "RAM available for (Application) 2.5GB.

My Mac pro (2.1) 3.0GHz intel 8 core X1900 512mb encoded the 100mb file in - 11 secs

MacBook Pro 2.8GHz intel core 2 duo NVIDIA GeForce 9600M GT encoded the 100mb file in - 17 secs

Imac 2.5GHz Intel core i5 AMD Radeon HD 6750M 512mb encoded the 100mb file in - 8 secs

Should I be disappointed in my 8 core? should I sell it and edit with my imac? Ive received another imac i7 and arrives today so im going to test the speed of that one as well. I have a thunderbolt drive coming with it as well. I love mac pro's but now that we have thunderbolt do I really need a mac pro? seems to me that the imac will be fine for editing big shows.

Has anyone got any suggestiosn or thoughts

ThANKS

As you've seen, more cores does not necessarily equal more speed. Processor architecture and clock rate have a lot more to do with "real world" performance. Few programs are engineered to take advantage of more than one processor, let alone 4 or 8 - and make no mistake, they must be specifically designed for this purpose. So, what you're likely seeing is that the newer architecture i5 CPU is more efficient at this specific task than the "heavy metal" Xeon CPU (which is more designed for enterprise / data processing / application tasks).

3 seconds difference shouldn't amount to a hill of beans. I'm sure there's other benchmarks that the Mac Pro will trounce the iMac on. Don't sweat the small stuff.

Your 4/8 cores on The mcp is virtual and there fore not speeding up your work.