jp2 very slow (10 times slower than jpg)

We're using imagemagick 6.3.0 and are experiencing VERY slow performance 
whenever we're processing jpeg2000 images

time identify xtci_e8N7N3G4q0G4Y2v9nXga_0.jpg
xtci_e8N7N3G4q0G4Y2v9nXga_0.jpg JPEG 1330x998 1330x998+0+0 DirectClass 
8-bit 797.195kb 0.720u 0:02

real    0m1.384s
user    0m0.644s
sys     0m0.144s

time identify xtci_e8N7N3G4q0G4Y2v9nXga_0.jp2
xtci_e8N7N3G4q0G4Y2v9nXga_0.jp2 JP2 1330x998 1330x998+0+0 DirectClass 
8-bit 444.418kb 13.940u 0:15

real    0m14.125s
user    0m13.535s
sys     0m0.482s

is the expected performance or is something very wrong in our 
imagemagick installation