OpenVPN hardware requirements

[Dexter <dexter@madalbal.sk>]

Hi,
we have 1Mbps/1Mbps internet connection. We have firewall with hardware:
Pentium 400MHz, Ram 192 MB. We use it as firewall, proxy (squid) and
OpenVPN server.  Is this hardware enough? To me it seemed, that it's
enough, untill I have run also OpenVPN client on this firewall that
connected to other network, so that our local network could easily acces
this other network. I noticed that running OpenVPN client on firewall
made slover connection as if I have run OpenVPN client directly on PC.
So this lead me to conslution, that our firewall hardware is not enough
for OpenVPN (client or server).
What do you thing? What hardware do we need?
Thanks alot.
      Dexter