HOW-TO:Modify the video cache

Template:Gotham This page describes three advancedsettings.xml settings that can be used to maximize the cache that XBMC uses. You can use all or just a couple of these settings to see significant improvements in cache performance, should you require it.

What is the video cache

During playback from internet sources, XBMC will cache the video in RAM for a little bit. If the data rate of the video file is too slow for live playback, XBMC will pause until it can fill the cache enough so that it won't need to pause anymore. Sometimes XBMC doesn't have enough RAM and will give a "cache full" error message. XBMC has various advanced settings that can be used to tweak this behavior.

What this guide won't do

Even if you change the cache settings in XBMC, that won't change how fast the video file data comes in over the network.

• It won't make a slow server load the video any faster.
• It won't fix a slow local network.

What this guide will do

• Often the problem isn't that the network/server is consistently slow, but rather that there are dips in network/server performance. Filling the cache, even when XBMC doesn't think it's needed at the time, will help smooth out performance. Hopefully to the point where the video never has to pause in order to playback the entire file. When using wifi this can also mean filling the cache up before potential intermittent wifi interference, which can happen unpredictably.

• Increasing the rate and size of the cache can also reduce network congestion. On a healthy 100meg LAN, a TV episode can often load in seconds, and then leave the network's full bandwidth to other tasks.

• Battery life can also be increased on devices in at least two situations by modifying these cache settings:
  1. First is a situation on certain devices that sustained slow/medium-wifi usage, over the length of the video will use more power than using fast-wifi usage for a shorter time. In other words, slowly loading a video file that is 30 minutes long, over a period of 30 minutes, can actually take more power than loading a 30 minute video in 5 minutes, even though more wifi speed/power is used during the 5 minutes.
  2. Second is a situation that by keeping the cache in RAM (which requires a lot of RAM for this to work), but increasing the size and fill-rate, so that sustained hard drive use is decreased. In this case the cache is being used even though all the files are local, and no network is being used at all.