why Mac pro is better & more expensive than IMac?!

Better value: Mac Pro 6-core 3.33GHz. You can buy base and throw in W3680.

You won't outgrow a Mac Pro.

Buying RAM and hard drives and doing upgrades on MP is easier and cheaper.

Right now iMac looks fine but faster plus more cores IF the software can utilize them well.

Check www.barefeats.com

http://www.macperformanceguide.com has much more details on why

iMac:

No expansion slots, any possible upgrades difficult or pay Apple

One internal drive bay, Apple brand Hard Drive required, 2TB max.

Memory expandable to 16GB, no error-correction

If the display dies, repair can be expensive

Up to one additional display

ThunderBolt port included

recent update means it is fast

Mac Pro:

up to three additional PCIe expansion slots, graphics card replaceable

upgrades can be do-it-yourself

Four internal drive bays, any brand and capacity supported

Memory expandable to 64GB, Error Correction Code feature included

Separate display means display and computer can be upgraded separately

Three display support included, many additional displays possible

no recent update means it is not as fast in the default configuration

No ThunderBolt yet, but expected in next update (overdue)

Two processor chips (each one with six computing cores) running at 2.666GHz means only that. You can NOT add the numbers together. You only get better performance when all cores in BOTH processors are perfectly and completely busy. With today's software, that does not happen very often. You will mostly be better off with two separate computers, each running at 2.66 GHz.

The processors in a Mac Pro can be upgraded a few steps in speed, but the upgrade is difficult. Dual Processor Mac Pro upgrade is even more difficult.

Apparently you don't fathom or realize what I said:

Better value: Mac Pro 6-core 3.33GHz. You can buy base and throw in W3680.

You can buy a single 6-core like that from Apple and pay $900 more.

I do not recommend 12-core.

I do not recommend the slower 2.66 processor

I do recommend avoiding the 2009 model.

Better off starting with the 2.8 4-core and go from there.

Ivy Bridge socket LGA2011 will have a lot of other features making them the "to die for" but no one knows and I for one would not want to be on cutting edge with any chipset or new revision. Seriously, Apple has always had issues with first silicon whether 2011 MBP or iMac or 2008/2009 Mac Pro. And always takes a couple OS updates. And then things break. And then software has to catch up.

A slower 12-core is not going to future proof. It is going to cost more and not deliver.

For last year we've all been seeing and saying 6 x 3.33.

why I sent you link to MPG site.