Just to summarise the outcome of all the observations on the improved disc cache.
The improvements make the cache viable on many more supported systems, including more RISC OS systems. On PC with modern OS it made no great improvement as their OS could already cope with the directory layout and had a plentiful write speed already. No test I ran on PC saw the write rate, before or after the changes, drop below 30 megabytes a second. Although the updated cache does use less processor time to achieve its results. On RISC OS the benefit is stark and very clear. Most tests show a five fold or more improvement in write performace using the new code and many fewer directories created. The sumamry of results from all the data points I have access to: +------------+----------+ | System | Rate K/s | +------------+----------+ | Rpi | 7 | | ARM mini | 33 | | Iyonix [1] | 300 | | a9 | 500 | | vrpc | 570 | | ARMX6 | 2700 | +------------+----------+ This shows that the disc cache is now useful on RISC OS for most non SD based systems. The Raspberry Pi running RISC OS and the ARM mini both appear to react very poorly indeed to the write pattern used by the disc cache. Users on such systems should ensure the cache is disabled by setting it to 0 size in the options. The Iyonix is a bit of a difficult one to call, its disc write speed appears to be very volatile. Though on average it is beneficial to enable the cache on this hardware. The standout here is the ARMX6 which is managing a very respectable (for RISC OS) 2.7 megabytes per second with the new code some 8 times better than before the changes. [1] The Iyonix write rate seems highly variable and ranges between 90 and 400 K/s -- Regards Vincent http://www.kyllikki.org/