OT HP3000 question

I have inherited a HP3000 918LX. Surpisingly enough it is OT being from 1999 or thereabouts; hopefully MPE/IX is venerable enough to fit in here. I didn't like the machine much when it was in production use as a billing system, but now that its mine I appreciate it a bit more. However, the thing came out of the box in 1999 with MPE 5.5 with 64MB of RAM and was intolerably slow. It was since been migrated (by HP consulting thank goodness) to 7.00 which did not speed it up any. Running a few simple commands and GLANCE begins to gripe about memory and CPU usage. I once exported an ASCII file from LOGTOOL and tried to 'grep' the resulting file in MPE POSIX mode and it took over 2 hours to complete. FTPing to a 90mhz (!) linux box and the grepping took three minutes. This was one of the machine were HP inserted NOP's in the firmware so you didn't get more speed than you paid for, but I would not mind adding some RAM. I have some A2580-60001 60ns RAM from a HP9000 D200 which looks to be compatible with a 918LX. I found other RAM part numbers which claimed to work with both D200's and 918LX's had trouble finding info on this one specifically. Anyone know for sure? I'd rather not release magic smoke. Paul