Maziar :
Hello and welcome to the forums
Yes iMac CPU is faster:
http/www.apple.com/macbookpro/specs-17inch.html
"2.53GHz Intel Core i5 processor with 3MB shared L3 cache; or optional 2.66GHz Intel Core i7 processor with 4MB shared L3 cache"
http/www.apple.com/imac/specs.html
" 2.66GHz quad-core Intel Core i5 processor with 8MB shared L3 cache; Turbo Boost dynamic performance up to 3.2GHz
2.8GHz quad-core Intel Core i7 processor with 8MB shared L3 cache; Turbo Boost dynamic performance up to 3.46GHz; Hyper-Threading for up to eight virtual cores"
You missed this part of the new MacBook Pro specs:
Turbo Boost.
Intel Core i5 and Core i7 processors also feature Turbo Boost. If you’re using processor-intensive applications like Aperture 3 or Final Cut Pro that would benefit from an extra performance kick, Turbo Boost dynamically increases the speed of one or both cores, taking a 2.66GHz MacBook Pro all the way up to 3.33GHz.
Hyper-Threading.
Built-in Hyper-Threading allows two threads to run simultaneously on each core, so Mac OS X recognizes four virtual cores instead of just two. When you’re running multiple applications at once, the Core i5 and Core i7 processors spread tasks more evenly across a greater number of cores — so you can get more done, faster.
Integrated memory controller.
Unlike systems that connect memory to the processor through a separate controller, the new MacBook Pro uses an integrated memory controller to connect memory directly to the processor. In a sense, this cuts out the middleman. With faster access to memory, each core gets right to work on your data, rather than waiting for it to arrive. Together with up to 4MB of shared L3 cache, the integrated memory controller ensures MacBook Pro can keep up with you.
May not make them as fast as the new iMac but certainly faster than you implied.