I just compared `time cat file` in SecureCRT and PhpED's terminal. Picked sufficiently large text file.
Terminals was tuned to be "the same": xterm, same font, same color, same work size
The results are below:

real 2m34.484s
user 0m0.016s
sys 0m0.988s

and
real 0m24.938s
user 0m0.000s
sys 0m0.168s

What I noticed is PhpED re-paints window significantly less frequently, leaving more time to network operations which in its turn results in faster results.