Use compression strategies

You can either compress the entire IFS or compress individual files in the EFS. (If you're using Instant Device Activation, you can't compress the IFS.) Besides saving flash memory, compression can also speed up boot time. In systems with very slow flash access, it often takes less time to decompress files out of flash than to do a straight copy of the larger uncompressed file (enable the cache in the IPL to reduce decompression time). If your system's flash timing is on the slow side, try using compression; the decompression code might be able to run completely out of the CPU instruction cache. Of course, this depends on what else the system is doing during the boot; you'll need to try both approaches and measure which is quicker.