Over at the “Jeff said so” blog there is a great write up on Fusion-IO in a UCS B or C series.
The Fusion-IO card could be great for Database Redo logs or other applications that need “crazy IO with 0% latency”. The Fusion-IO card is fast and it is compared to SSD in the article below. I think the card is neat but would always be a “loser use case” and unfortunate to have in a UCS B or C series, as it gives the server a personality. A dead blade cannot be fixed via moving a Service Profile. I would use a SSD SAN rather than a Fusion-IO card.