Re: Question about optimum cache size.

[Lyle Seaman]

Paul Blackburn <[EMAIL PROTECTED]> writes:
> It is interesting that you believe "A memory-based cache does not
> usually improve performance". Having used both disk and memory based
> caches. My experience is that a RAM cache is considerably faster.

Modern OSes actually maintain a memory-based cache of the disk, so even
when you use a nominally disk-based cache, you are actually caching the
hottest data in memory as well.

In some cases (probably heavily write-biased workloads, with poor
locality of reference), memory-based caches will outperform disk-based
caches.  On the other, no cache at all would perform even better.