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3 fine-tuning alice, Memory footprint, Multi threading – ARRI Projection HDTV User Manual

Page 24: Configuration

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4.3 Fine-tuning ALICE

Memory Footprint

The amount of memory ALICE consumes depends on the

maximum image size to be processed, and the maximum

size of its internal image cache.

The image cache limit can be influenced by the

environment variable ALICE_MEM_FRACTION.

Its value is the percentage of the memory marked available to

the application by the operating system. Default is 0.25,

meaning that a quarter of the memory is the upper limit of

the image cache. Note that this is the image cache only,

not the total memory footprint of the application. The

environment variable can be set in

‘c:\cshell\login.csh‘.

Multi Threading

Besides running parallel to image loading and recording,

the image processing can operate multi-threaded to make

optimal use of the dual CPU system.

When running ALICE at the same time as recording on

the same host computer, multi-threading can be switched

off by setting ALIP_THREADS to 0.

This affects both ALICE as well as image processing for

recording. Setting ALIP_THREADS to 1 turns on multi-

threading, while setting it to “auto” causes the multi

threading to be turned on, but to be disabled it temporarily

if both ALICE and aldaemon are running at the same time,

to allow interactive working with ALICE while computing

data-intensive recordings. The auto setting is also the

default if the environment variable is not set. The

environment variable can be set in

‘c:\cshell\login.csh‘.

Configuration

4.3.