Raspberry Pi general optimization
- Use a class 10 SD card for best speed. The USB bus can't come much higher than 30MB/s so you don't have to buy any extremely fast ones though. Not all cards are compatible, check the compatibility list: http://elinux.org/RPi_SD_cards
- Use the HardFloat version of Raspbian instead of the SoftFloat. HF has much faster floating point operations - however SF is required for running Java. So it's either Java or performance, like normal.
- The official Raspbian image gives low network speeds: http://elinux.org/RPi_Performance#NIC
- A graphics driver by Simon / teh_orph is using hardware acceleration for some instructions: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=28294 installation instructions: http://elinux.org/RPi_Xorg_rpi_Driver
- The firmware can be upgraded which gives, among other things, better GPU performance.