HP got an early jump on April Fool’s day yesterday when they announced their new blade server, the Proliant BL260c G5, with the claim that it has 64% better energy efficiency than the Dell PowerEdge M600 blade server.  The details of this Internet Vaudeville act can be found here: http://h71028.www7.hp.com/enterprise/downloads/HP_ProLiant_BL260_SPECjbb2005_032808a.pdf

Normally, vendors try to establish comparisons using similar configurations, such as those done by Principled Technologies here: Yes, Dell commissioned this work, but if you look at Appendix B of that report, you'll notice that a professional rigor was applied to making sure there was a level playing field.  By contrast, the HP report published yesterday makes no attempt at comparing similar configurations.  Different processors, running in different power modes with different memory and disk configurations, etc.

If HP had substituted one of their own servers in place of the M600 – one that was actually comparable to the M600, such as the BladeSystem c-Class tested by Principled Technologies, the power savings would probably have been over 75%, instead of the 64% they reported.  But they couldn't very well come out and say that their high mileage lab experiment was so much better than an HP product that many of their customers already own.