Of course compression/encryption takes CPU time. It turned out that an
old Pentium-133 is able to encrypt and compress about 1GB/hour -- that's quite
a lot. If you compile SSH with the option "--with-none" you can
tell SSH to use no encryption. That saves a little performance. Here is a comprise
between several download methods (during the test, a noncompressed 6MB-file
was transfered from a 133MHz-Pentium-1 to a 233MHz Pentium2 laptop over a 10MBit
ethernet without other load).