It is possible to have more than 10 users on an older pre-xenon machine it is just relly slow.compared to modern server processers specifically desinged for a large number of users. Here's the minimum recomended sepcs per users. 1-3 users Pentium 166 or higher (thats the least powerfull processer that can eficently run most modern versions of linux).128 mb ram, atleast 80GB HDD, nic card. 4-6 users Pentium 2 300 mhz, 256 mb ram atleast 140 GB HDD, nic card. 7-10 users Pentium 3 500mhz, 512 mb ram atleast 200 GB HDD,nic card. 10-20 users Single Xenon or Optatron,1GB ram,atleast 400GB HDD,nic card. 20+ users Dual Xenon or Optatron, 4GB ram,atleast 1 TB HDD,nic card.