we need a lot more information than "50 agents"
also, you do not have "GoAutoDial" version 2.2.1-237. You have VICIDIAL version 2.2.1-237. GoAutoDial is only the Installer, and is probably version 2.0CE. Vicidial is the Dialer software that you are using (which can be installed from scratch onto any Linux server, or via GoAutoDial or via Vicibox Redux or even Vicibox (classic) or VicidialNOW.
If your agents show paused on the real-time but ready on their screens, do their clocks on their agent screens work? can they push "pause" and "resume" successfully?
Given the odds you are either way overloading your server (uptime, top, htop will all show "server load" averages for the last 1,5,10 minutes) or your network connection between your agents and your dialer is not good.
If you want an opinion on a 50 agent server, first you should understand that Vicidial is "Clusterable" (it is possible to Group several Vicidial Servers together to act as one, reducing the need to purchase a "SuperComputer", but instead using several less expensive boxes).
Ordinarily you can get 25 agents on a Core2Quad. but there are a lot of factors: bandwidth, codec, protocol (sip/iax?), telephony hardware if any (digium/sangoma), number of channels being dialed per agent, inbound vs outbound ratio, avg call duration, maximum live channels, are you recording all/some/none of the calls (and anything else you can think of!).