Read that chapter if you encounter some performances drawbacks
or
if you want consume less memory, disk, CPU or Network bandwidth using
Jajuk.
On a PC/P4M 1.8Ghz, Jajuk uses about 9% CPU for mp3 and 3% for Ogg Vorbis. On a Centrino 1.8 Ghz: 0% CPU.
A JVM runs inside a reserved memory heap. The JVM takes all the Xms MB of memory at startup and requires more memory to the OS only if necessary. For a big size collection and all cover options enabled, it takes about 65MB maximum of memory but 40MB should be enough most of the time.
If you have a low Internet connection, avoid using advanced online covers options (see next chapter).
If you use a network drive-type device, check refresh frequency (default: 5 mins) because Jajuk scans all the device with this given frequency and this uses bandwidth. Increase duration if the collection changes few.
These options are available in the Parameter View / Cover tab.
"Use auto-cover" option (default=yes) uses network bandwidth, especially if you use "Preload Cover" option. Avoid this option if you have a low bandwidth.
"Preload covers" (default=no) is very network bandwidth consuming. Use this option only if you have a fast network like xDSL or cable.
You can reduce covers size by setting lower minimum and maximum cover sizes.
You can increase or decrease the time out when downloading a cover in the Parameter view/ Network tab.
These options are available in the Parameter View / Advanced tab.
If your collection uses mainly non-European characters (like Asian languages), choose UTF-16 as collection encoding : that will reduce collection file size and accelerate startup parsing. Do not use this option if you use European languages because you collection file would then grow.
Animation view uses Java 2D. CPU overhead can be significant, especially with screen resolution higher that 1200x1024. On a P4 1.8Ghz with a resolution of 1024x768, the overhead is about 2 or 3% but reaches 10 or more with a resolution of 1400x1200.
We recommend Sun JVM 1.5
If you have a really big collection (something like > 200GB), you may increase -Xms parameter.
You can set a -Xmx parameter to restrict memory usage to this value (example: -Xmx100M), but this could conduct to unpredictable behavior when out of memory errors occur.
Use -Xloggc:<file name> to trace memory usage if needed.