If I try to run MongoDB on a desktop-grade machine, what performance should I expect? Let's suppose I'll have a regular SATA drive, something like Core 2 Duo and 4 or 8 GB of RAM. Will it be comparable to MySQL which runs on a middle-grade server machine with SCSI RAID, multiple CPUs and other good stuff?
Also, I'd like to know the same about CouchDB.
In fact, I'm going to try it on an even more crippled machine, like my development netbook or notebook. But I'd like to hear if somebody already has the experience. Add your story if you tried anything like it.
EDIT: To clarify the question, what I want is not a development environment or a desktop application. I'm investigating the possibility of running real web apps with quite some load on a cheap desktop hardware.