Also what determines the optimum buffer size?
I wrote this for the 3.2 FAQ, it also applies for you too.
4.8 * How can I speed up disk operations?
We already have a cache system built-in that it is severely
underused. That is the case of buffers that can be set within
HDToolBox in a non destructive manner, or by using the AddBuffers
command.
Nobody usually tweaks this values, and this is a huge performance
boost possibility that often gets overlooked.
Buffers are file system independent, so they should be safe to be used
under any AmigaOS compatible file system.
This is a rough guide that will attempt to provide you with advice on
how much memory should be destined for buffer usage, so take it with a
grain of salt. It really depends on your Amiga habits and your
hardware configuration. So don't be afraid to tweak these values and
experiment in order to achieve the best results.
For any drive, remember that each partition in your system will have
buffers by default assigned to it, so first check what amount they use.
And also consider that all those partitions, no matter which one is
bootable, will add their buffer usage to generate a grand total.
Yes, buffers are great, but they are certainly not for free, as they
consume ram.
Buffers only make sense when the data to be cached will be accessed
several times, and for that to happen they need to be preloaded with
something to start caching. So the idea is that the system will get
much faster from the second time onwards that it accesses the same
data.
The following is the total amount of buffer ram usage we recommended
(it should be divided between all your partitions). Note that all
values are approximate.
Total system ram - Recommended amount of ram to add to buffers
2 MB - Don't add more buffers, you can barely run the OS!
4 MB - 128 KB (256 buffers)
8 MB - 256 KB (512 buffers)
16 MB - 512 KB (1024 buffers)
32 MB - 1 MB (2048 buffers)
64 MB - 2 MB (4096 buffers)
128 MB - 4 MB (8192 buffers)
256 MB - 8 MB (16384 buffers)
To apply a change to the system buffers just add the corresponding
buffer value to the volume/s you wish. The easiest method is by simply
modifying the startup-sequence in the AddBuffers line.
