Testing zx8 (ps) against RC4 and ISAAC reveal that the output of byte per
second is slower, as expected. This is due to the fact that RC4 has fewer
operations per output byte and ISAAC output 4 byte at once.

These are my results, were each cipher has to complete 3.000.000 runs
genereating 1024 byte each run.

Code:
===================================================
Benchmark Runs   : 3000000
Byte Test Size   : 1024
===================================================



Hardware Overview: Intel Core 2 Duo
	Processor Speed: 2,2 GHz
  (dedicated hardware)

===================================================
Cipher Benchmark : RC4
Elapsed time     : 12.16 seconds
Speed            : 240.0 MiB/s
===================================================
Cipher Benchmark : ISAAC (32 bit)
Elapsed time     : 8.35 seconds
Speed            : 349.0 MiB/s
===================================================
Cipher Benchmark : zx8
Elapsed time     : 21.94 seconds
Speed            : 132.0 MiB/s
===================================================


Hardware Overview: Intel Core i7
	Processor Speed: 2,2 GHz
  (dedicated hardware)

===================================================
Cipher Benchmark : RC4
Elapsed time     : 9.97 seconds
Speed            : 293.0 MiB/s
===================================================
Cipher Benchmark : ISAAC (32 bit)
Elapsed time     : 2.64 seconds
Speed            : 1111.0 MiB/s
===================================================
Cipher Benchmark : zx8
Elapsed time     : 17.85 seconds
Speed            : 164.0 MiB/s
===================================================


Hardware Overview: Intel Xeon 3360
	Processor Speed: 2,83 GHz
  (non-dedicated hardware)

===================================================
Cipher Benchmark : RC4
Elapsed time     : 10.84 seconds
Speed            : 269.0 MiB/s
===================================================
Cipher Benchmark : ISAAC (32 bit)
Elapsed time     : 3.96 seconds
Speed            : 739.0 MiB/s
===================================================
Cipher Benchmark : zx8
Elapsed time     : 21.38 seconds
Speed            : 136.0 MiB/s
===================================================
The source code for running these tests can be downloaded here

http://www.freecx.co.uk/zx8/benchmark/