Do S-spec numbers matter when 2 X CPU

[blessed48]

Looking at two processors, X5355 SLAC4 and another X5355 SL9YM. The second group of numbers, I now know are the S-Spec numbers.

Up-grading my recently purchased Mac Pro 1.1 from 2 X Dual core to 2 X x5355. Both X5355 are stepping B3, but the S-spec numbers differ. Must the S-spec number on both new X5355 match for this 2 X X5355 upgrade? Is the answer consistent for all Mac Pros?

Thank you

 

[blessed48]

Best stepping (B3?) & best S-spec

for the Xeon 5355, is there a best stepping and/or best S-spec?



Thank you

 

[Hellhammer]

As long as the steppings are the same, it will work.

 

[blessed48]

all the same?

Is one stepping desired over the other for the x5355? What does the S-spec represent?

 

[blessed48]

This is critical information for anybody upgrading a Mac Pro 1.1 from 2 X dual core to a 2 X quad. The upgraded CPU is a Xeon 5355 2.66Ghz quad core. There are a couple of stepping and three S-spec series. There may be more than one s-spec series for a stepping. Why? Not really sure! As long as the stepping is the same for both processors, they should work in together in a single system. I would still recommend matching the S-spec series if possible.

However, I did find an important improvement in the stepping GO. The GO reduces power consumption and heat. Remember you are nearly doubling the power (it scales well but not perfect) and will produce more heat. You may need to change some settings in the BIOS related to fan speed and tempter.

For the upgrade, use X5355, stepping GO, and S-spec=SLAEG. There is only one S-spec with stepping GO.

Last, note the Clovertown Family of processors include the Xeon 5365 running at 3.0Ghz. Still a bit pricey at this time, 11/25/2011, and early models have a greater power demand and create more heat but maybe an option. Later Xeon 5365 had stepping that did reduce power and heat Anybody with answers on the 5365, please jump in.

Hope this helps you get there faster and with the better processors.

Thank all who added to the thread. As an old PC guy, new to the Mac world, I look forward to leaning more daily.

Thanks