Hi, since i've installed and activated Imagick extension the thumbs generation is too slow and it consumes a lot of memory in my server..
This is normal? Do i have to do a special configuration in my server to boost Imagick speed?

Thank you.

Actually imagick is faster and has better memory management than the GDlib. Sure you really enabled it? (just asking). Regarding server config you should contact your host.

Well my Options->Image tab says my php has support for Imagick and it's checked..
Very strange because it was a lot faster with GDlib but the thumbs had some artifacts.. With Imagik the thumbs are perfect but has the problems described before..
My images have around 3/4 mb each.

As you hopefully know from our user guide the file size is not what matters.

Anyway you should contact your host if you think something starts to act weirdly. There has no significant change in that area in ZP recently, as far as I remember