How many SIP/IAX2 trunks a asterisk cpu can register

How many SIP/IAX2 trunks can have a CPU with 1.0 speed, 512 of RAM
I mean, with how many trunks the PBX work fine?
They are unlimited?

What exactly did you mean by a CPU with 1.0 speed?

AFAIK, a PBX can have as many trunks as its storage, i.e. hard drive, etc., can hold.