X5687 vs X5690 CPUs for a SQL 2008 R2 Server

Question

I have the choice between:

2 x X5687 (Intel® Xeon® Processor X5687 - QuadCore (12M Cache, 3.60 GHz, 6.40 GT/s Intel® QPI)

or 2 x X5690 (Intel® Xeon® Processor X5690 - SixCore (12M Cache, 3.46 GHz, 6.40 GT/s Intel® QPI)

for a new DB Server (SQL 2008 R2 64bit), my personal preference is X5690, are there reasons that would speak against going for a SixCore CPU vs. a QuadCore CPU ?

Answer 1

For 2008R2, I'd take the extra cores every time.

If the server might be upgraded to Denali/2012 on release you may need to factor in the switch from per socket to per core licensing. @MrDenny summarised this well in SQL Server 2012 Licensing Changes.

Answer 2

Obviously from a hardware perspective, I'd go with the X5690. Just make sure to check with the licensing agreement you have with Microsoft. I thought I remembered reading somewhere that there's a SQL Server 2008 licensing option that requires you to have enough licenses on a per-core basis.

As long as you don't have that, I'd say go with the X5690. If your agreement does mandate licensing on a per-core basis, then check and see if two more cores justifies the increase in cost.