Hardware requirements for g729?

Is there a document that describes the hardware requirements if you want to use the g729 codec? I’ve seen posts in newsgroups that it uses alot of cpu since it is a software compression codec. Just looking for guidelines when spec’ing out an Asterisk server.

How many concurrent calls are you expecting peak?

I’ve got a 3.0ghz Xeon with 1gb ram handling 30+ g729 calls without issues. cpu load around 50% (more when performing additional transcoding)

Two, rarely three concurrent calls. Most will be via a VoIP provider, a few via my TDMxxx card which is connected to two land lines ( home and office ). I am moving my office line to the voip provider soon so there will only be one land line. I’ll probably sell the TDMxxx card since it is overkill for that.

My Asterisk server is:
HP e800 server
Pentium III 866
512MB ram