Adding second processor

In Windows 2000 server, I have added Terminal Services for two remote stations to login. Now the screen saver does not move smoothly. Server is PIII 1GHz L2-256K, 133 Bus with 512 MB RAM running. Server is used for PacWare database application for about 15 users. It also runs Symantec Antivirus small Bus. It is the PDC, runs DNS, DHCP, etc. (single server environment). I increased RAM to 1024 MB. Users complain of slightly slower response in the afternoons, but still workable. CPU utilization stays around 95-100%. There is an empty CPU socket 370, so I thought I would add a second CPU. My processor says Pentium III SL5DV on the chip. Do I need to match these numbers? or is 1000/256/133 enough??

Thanks,
Jon