QMS 860, User Manual, Page: 340 / 398

that have characters already stored in the font cache is immensely
faster than printing characters not yet in the font cache.
As the font cache memory fills, the printer erases bitmapped
characters that have been in the cache longer than the others without
being used to make room for new characters. By increasing the
memory allocated to this client, the printer can store more
characters and spend less time erasing and replacing characters in
the cache.
Normally, you do not need to change this memory client unless you
use a large number of fonts at various point sizes. If you do, you
may allocate additional memory to this client to improve printer
performance. There is no specific formula to use in figuring the
amount of memory required by the font cache, but after a certain
point, large font caches cause the printer to take longer to print than
smaller font caches because of the search time through the cache.
The recommended font cache size is in the following ranges:
■ 128 KB to 256 KB for 300 dpi printing
■ 256 KB to 512 KB for 600 dpi printing
You should experiment to see what font cache size works best for
you.
PS Heap
Also known as K Mem PS Heap, PostScript VM, and Virtual
Memory, this client holds downloaded fonts, PostScript operators,
and forms.
Inefficiently coded PostScript jobs can consume an infinite amount
of virtual memory or leave objects in the PostScript heap after the
Appendix F
F - 1 2 A d d i t i o n a l T e c h n i c a l I n f o r m a t i o n