lol, with those specs you can only provide pissing small servers. That's not really a bad thing, but if all servers are on that machine, forget it.
yeah, you would be lucky if that machine can handle 2 20 slot servers on nexus at once (you can probably do 14+2 * 2 at most)
edit:
<crocodile dundee>tha's not a server. now this, this is a server:
• 2 x Intel Xeon 3.0GHz Dual Core 5050 Dempsey CPUs (2-procs/4-cores) & 667MHZ FSB Speed
• 1GB FBD ECC 533/667MHz RAM
• 250GB SATA-II 3Gbit/s drive
• 1 IP address included
• 1800GB/mo. data transfer
</crocodile dundee> (i know, or RAM sucks)