(v13) Configuring multi-threading and Harlequin Parallel Pages

This page applies to Harlequin v13.1r0 and later; and to Harlequin Core but not Harlequin MultiRIP.

With Sentinel LDK security, multi-threading and Harlequin Parallel Pages is enabled with the use of a new product key.

The parameters are configured in a file containing the following PostScript language code. It can be placed in Sys\HqnOEM:

                      <<
                        /NumDisplayLists 2
                        /MaxThreads [2 3]
                      >> 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 the /MaxThreads system parameter control busy, but may temporarily restrict or over-subscribe the number of threads for short periods.

/MaxThreads can be an integer or an array. If it is an integer, it sets the maximum active threads (the maximum number of threads is raised, if it was lower than the new value). If it is an array, it sets the maximum active and the maximum number of threads the RIP can use (limited by the product key). Both of these are limited to the values passed via SwStart() (which comes from the -p parameter in the skintest example).

You can set the maximum number of threads using the -p parameter. The -p value is used as the default for the number of active threads using the -p parameter.

/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 seen when the /MaxThreads value is set slightly lower than the maximum number of threads (the limit). Values for three active threads and five maximum possible threads might be suitable, depending on the number of cores available on the hardware and what other processes are running. However, /MaxThreads could temporarily be decreased to allow processing of a problem job. In addition, even if you had an “unlimited” product key you may choose to set the maximum number of threads (the limit) to 8 (for example), so that the core RIP does not use too many threads.

The values returned for /MaxThreads in currentsystemparams show the settings that were actually made after taking the limits set by SwStart and the current product key for multithreading limits into account. Note that this doesn't tell you how many threads are actually running at any one time.

You can set a maximum value of /NumDisplayLists 5. Higher numbers of Harlequin 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 of Harlequin Parallel Pages from 1 to 2 . Each further increase provides less benefit than the previous one.

Harlequin Parallel Pages has no effect if there is only one thread.