Principled Technologies have undertaken some hardware benchmarking to compare the new(ish) IBM x3850 M2 with an HP ProLiant DL580 G5.

The IBM machine comes out on top with 27% better performance per watt and 8% more performance
from the vConsolidate tool.

I found a fantastic document over at SQLCAT that outlines how to troubleshoot and diagnose performance issues in SQL Server 2005/2008.

I’ve blogged about it here as the principles are just as applicable to SQL Server in a physical or virtual environment.

Enjoy reading this small, but very succinct document here.

This website is awash with great articles, so if you get chance to check it out then do.