RokuMarkn » Fri Aug 05, 2011 5:22 pm
The nonvolatile channel memory in the Roku2 is used as a cache. When starting a channel, if the channel is in the cache, it is started immediately. Otherwise the channel data is downloaded from the Roku channel server into the cache and then the channel is started. Least recently used channels are ejected from the cache if necessary to make room for the current one.
The SD card just increases the size of the cache, so you can fit more and/or larger channels in the cache without needing to download them as frequently.
"Netflix Player" N1000X
XDS 2100X (premature death by lightning)
Roku2 XD 3050X
Roku2 XS 3100R