We have a 512MB high-density (4x64) PC133 RAM. I just found out that it doesn't work on the PCI G4 which my boss has (oops!) so we're thinking of taking out the 256MB in the iRack (iMac DV SE) and puting that in my boss' computer, and puting the 512MB SDRAM in the iMac.
I can't find any information regarding the iMac DV SE and using high-density RAM in it.