Blade computing works best when organizations apply a ‘one-size-fits-all’ strategy, meaning all the blades in the chassis are as similar as possible and ideally, identical. This means same cpu, same speed, same memory, same everything, including the same vendor. By standardizing on blade servers, operating procedures can assume that every component in the chassis is identical and IT operations doesn’t have to worry about the sensitivity of a particular server component to an application’s unique characteristics. This makes blades more swappable, easier to manage, simpler to back up and cheaper to acquire and inventory. Greater diversity within the chassis defeats many of the benefits of blade computing.
If for whatever reason, you don’t want to enforce this degree of commonality, it is advisable that customers take an N and N-1 approach to blade server technology, meaning standardize on a couple of blade server types, one current technology and one current minus one generation, replacing existing server technologies every few years to keep the infrastructure simple. The business benefits of commonality, as seen in the case examples will outweigh any incremental hardware costs borne by this approach.