What is the difference between the C0 and E0 stepping in the Intel Xeon 5400 family of processors?

Solution 1:

My understanding is that the "stepping" designators in a specific product line are for denoting minor revisions in the silicon. As they increment the feature set of a specific processor, they increment the stepping number. In the case of the processor you're looking at, it looks like the major difference between C0 and E0 is the max clock rate: 3.00 GHz vs. 3.33 GHz.

Am I going to see a difference between a C0 and E0 stepping in a MySQL DB server (32 GB RAM if it matters)?

Perhaps incremental performance improvements with the E0, but nothing significant.

Am I missing out on any critical functionality? Will it compromise the reliability of my production environment?

Nope, core functionality should be the same between different stepping revisions of the came product.

Is this totally worth it? (yes, subjective, but just this! :)

It's probably not worth spending too much time on.