Nehalem Turboboost - How much for Mac Pros?

[psingh01]

One if the big features of the Nehalem processors is the turbo boost technology. Does anyone know what the max frequency is for the different Mac Pro's? I know the new iMac can boost up to 3.46GHz, but I can't seem to find any documentation on the 2.26 Xeon.

[Pressure]

From Intel's product sheet:

1/1/2/2 are the available frequency bins (+133 MHz)of Intel® Turbo Boost Technology that are available for 4, 3, 2, 1 active cores respectively.

Meaning, 1 or 2 cores active = 266Mhz increase in clock speed (2.53Ghz).
3 and 4 only yields a 133Mhz increase (2.40Ghz).

[BeerdedOne]

I believe the rest of the 5500 series (2.66, 5550 & 2.93 5570) used in the dual processor configurations have higher turbo multipliers, 2/2/3/3. So:

Dual 2.66, 4 or 3 cores active = 2.93 Ghz
" " , 2 or 1 cores active = 3.06 Ghz

Dual 2.93 4 or 3 cores = 3.2 Ghz
" " 2 or 1 cores = 3.33 Ghz

http://www.anandtech.com/showdoc.aspx?i=3597&cp=2

http://www.anandtech.com/showdoc.aspx?i=3597&p=7

One thing I've been wondering about turbo in the new i7 iMac, will they reach these higher clock speeds in the real world? The Pro has an over-engineered cooling system than can handle the 95W TDP with room to spare, but the iMac heatsinks are necessarily less beefy and more confined. How might this affect the ability of the system to reach the max turbo multipliers? It will be interesting to see benchmarks once these machines can be tested.

Edit:

Taking a closer look at that chart, it appear that there are 3 different turbo configs in the Mac Pro models:

single CPU are all 1/1/1/2
dual 2.26 are 1/1/2/2
dual 2.66 and 2.93 are 2/2/3/3

[psingh01]

Thanks!