Performance is a factor of both system performance and network speeds, combined with message length. The following benchmarks were generated on a 64 bit AMD Athlon 4200+ system running Ubuntu 6.6, with Ruby 1.8.5.

Analogger Speedtest -- short messages
Testing 100000 messages of 10 bytes each.
      user     system      total        real
  0.670000   0.090000   0.760000 (  1.981880)

Message rate: 50445.8148890823/second

Analogger Speedtest -- larger messages
Testing 100000 messages of 100 bytes each.
      user     system      total        real
  0.760000   0.100000   0.860000 (  2.351711)

Message rate: 42516.0306693639/second

Compare these numbers to numbers from the standard Ruby Logger:

Ruby Logger Speedtest -- short messages
Testing 100000 messages of 10 bytes each.
      user     system      total        real
  2.970000   0.910000   3.880000 (  3.874909)

Message rate: 25805.8322729287/second

Ruby Logger Speedtest -- larger messages
Testing 100000 messages of 100 bytes each.
      user     system      total        real
  3.130000   0.910000   4.040000 (  4.033219)

Message rate: 24792.8372501471/second

These numbers should be considered a starting point. I expect that future versions will improve on them.