PE 1950 PCI SSD

Hi,

Looking for advice...

I have a PE 1950II with a PERC5i and I need to add an SSD Drive to it to resolve an issue with our backups / deduplication cache, for which an SSD would work.

The problem is the 4 drive slots on the server are taken so I wanted to know if I could add a PCI SSD card to the server to get around this? 

If I can any ideas of what I can add?

Thanks