Another option is to replace the hard disk with an SSD such as
http://www.ebay.com/itm/Kinspec-32GB...item5d3b74ca83
You can get similar SSDs from the same maker in sizes 16GB, 64GB and 128GB. I put a 128GB in my H340. It will also fit right into a H320. You have to run Rockbox to use an SSD as the original iRiver firmware only recognises conventional hard disks. The advantages of an SSD are zero mechanical or electrical noise, no moving parts so increased reliability and very hard to damage through vibration, knocks or inactivity, much faster disk access so no lag, and I think power use is lower as well though I don't have figures.