Using CPU older than Intel Conroe Family

I have a full rack of older servers that I recently bought at an auction and had planned to create a RHEV cluster out of them. I had neglected to notice that the servers, ProLiant DL580 G4s, had CPUs that dated the Conroe family of processors. The processors in the machines fall into the Tulsa family and do not even show up under the CPU information on RHEV-M. Is it possible for me to use RHEV-H with these older processors or will I have to look elsewhere for visualization?