Multiple copies of "convert" in memory

[gregory]

the code (and data) is really only occupying one block of shared memory.

Not really. When I use IM 6.2.8 or 6.7.1 (with open-mp disabled) server's load average is about 1-2. When I install 6.7.6-5 server's load average is about 10-50. It doesn't seems to me that it occupies only one block.