100s of spam signups/min, can u limit # of signups/minute?

[whatsthegoodwor]

I'm getting a failed registration attempt (spammer) who is trying once every 3 seconds. Literally 1000s of attempts. Spam prevention is blocking them but it's really annoying and doesn't this create load on the server and slow down the site for legitimate users? Does it query the database when someone tries to sign up but fails?

It's from a different IP addresses every day from China or Canada, sometimes both at the same time.

Is there any way to limit the number of signups per IP per minute like failed logins? My host says blocking all of China through htaccess would slow down the site.