It's WebGL that gives your GPU away. I disabled it on Firefox, but some sites that I use often broke down. As far as I know it's not possible to enable it per-site. If you're on Firefox, there are settings to disable giving this information.

But the point, as the link emphasizes, is that if you don't allow such information to be read, that's also something to fingerprint you – actually even more, since it's a minority who take care of such privacy settings.