godchild77 :
Hello,
I have the apple store tell me they have broken my logic board in my 2008 4.1 Two 3.2GHz Quad-Core Intel Xeon processor mac pro.
Instead of fixing the want to give me a new 5.1 Two 2.26GHz Quad-Core Intel Xeon "Nehalem" processor unit claiming it is faster. Both are 8 core systems with the same ram etc. Is the 2.26GHz Xeon"Nehalem" system faster then my older 3.2GHz xeon system.
First of all, the systems do NOT use the same RAM. The 3.2 GHz unit uses DDR2 FB-DIMMs while the Nehalem-based unit uses normal DDR3. They will need to give you DDR3 RAM to go with the Nehalem-based unit as the DDR2 FB-DIMMs won't even fit in the RAM slots of a Nehalem Xeon motherboard.
Secondly, the dual 3.2 GHz Xeons (almost certainly Xeon X5482s) are going to be faster in most situations compared to the 2.26 GHz Nehalem Xeon E5520s. The Nehalems scale a little better in heavily-multithreaded situations, but they are trying to make up nearly a 1 GHz speed deficit compared to the X5482s. The E5520s will be slower in almost everything that uses less than four cores. It's not surprising, the X5482s were top-end chips while the E5520 is the slowest Xeon 5500 series chip that isn't horribly crippled by Intel (the crippled ones are E550x series chips like the E5504.)
Personally, I'd take Apple up on the offer of the newer motherboard, but I'd insist they also trade the DDR2 FB-DIMMs in for an equal quantity of DDR3-1333 RAM and give faster Nehalem chips than the E5520s. I'd try to get an X5550 as those have enough clock speed (2.93 GHz) to be competitive with the X5482s in lightly-threaded applications. If they play hard ball, the E5540 should be decent enough as well.