Exadata Database Machine X2-2 or X2-8? Sure! Why Not? Part I.

Blog Correction (28-SEP-2010). In the section below about processor comparison I originally stated ab erroneous aggregate core count for the full rack X2-2. I have edited out that mistake and left in place the socket-to-socket comparison which was the center of the point I was trying to make anyway.

I’ve been getting a lot of questions about why one would choose Exadata Database Machine X2-8 over Exadata Database Machine X2-2. That’s actually a tough question, however, some topics do spring to mind. I’ll start a list:

1. The Exadata Database Machine X2-8 only comes in full-rack configurations. No way to “start small.”
2. The Exadata Database Machine X2-2 only supports Oracle Linux. If Solaris is attractive to you then the X2-2 is not an option.
3. Database Host RAM. The aggregate database grid RAM in a full-rack X2-2 system is 768 GB but 2 TB with the X2-8. The list is quite long for areas that benefit from the additional memory. Such topics as large user counts (consolidation or otherwise), join processing, and very large SGA come to mind. And, regarding large SGA, don’t forget, the Exadata Database Machine supports in-memory Parallel Query as well.

Not on the numbered list is the more sensitive topic of processor power. While these sorts of things are very workload-dependent, I’d go with 16 Intel Xeon 7500 (Nehalem EX) processors over 16 Intel Xeon 5600 (Westmere EP) for most any workload.

So, readers, what reasons would motivate you in one direction or the other?