This page applies to Harlequin v13.1r0 and later; and to Harlequin Core but not Harlequin MultiRIP.
Both multi-threading and Harlequin Parallel Pages are layered options for the RIP, so the appropriate licenses need to be in place before they are configured.
In Harlequin Core, these are configured by PostScript-language options. Usually, this is done in a file run as the RIP boots, typically Sys\HqnOEM, though you could modify these settings in configuration file.
<<
/NumDisplayLists 2
/MaxThreads 2
>> setsystemparams
The /MaxThreads system parameter value determines how many threads the RIP attempts to use. The RIP tries to keep the number of threads set by this parameter busy, but may temporarily restrict or over-subscribe the number of threads for short periods. The number of threads is also limited to that allowed by the current RIP license.
The number of Harlequin Parallel Pages permitted simultaneously is set using the /NumDisplayLists system parameter.
You can set the maximum number of threads using the -p parameter to the clrip test harness. The -p value is used as the default for the number of active threads. /MaxThreads can be used to set lower, but not higher values for the number of threads. If /MaxThreads is not set, and your product key allows up to 5 threads you can set -p up to a value of 5.
Best results are probably seen when the /MaxThreads value is set to fairly small values between 3 and 5, but this depends on the number of cores available and the number of RIPs running as the Scalable RIP cluster. In rare cases, /MaxThreads could temporarily be decreased to allow processing of a problem job.
The values returned for /MaxThreads in currentsystemparams show the settings that were actually made after taking the limits set by the RIP skin and the current license for multi-threading limits into account. Note that this doesn't tell you how many threads are actually running at any one time.
Higher numbers of Parallel Pages require that more RAM is allocated to the RIP to store display lists and resources such as images and fonts. Testing has indicated that by far the greatest step gain is achieved by increasing the number from 1 to 2. Each further increase provides less benefit than the previous one. The maximum value of /NumDisplayLists is 5.
Harlequin Parallel Pages has no effect if there is only one thread.