On 7/5/2011 1:30 PM, Rudi Ahlers wrote: > On Tue, Jul 5, 2011 at 8:20 PM, Les Mikesell<lesmikesell at gmail.com> wrote: >> >> How much can that matter? Reads are going to be cached in main RAM >> anyway - which is pretty cheap these days. >> > > > Yes, but I suppose it all depends on the needs of the server in question :) > > In our case, with web servers, reads (i.e. opening websites, > downloading content) far outweighs writes (which are basically logs, > file uploads, and sessions being written to disk. > > In case of forums (we have many clients with forums) reads& writes > are sometimes equal, but even then reads are still more common in our > case than writes. But it doesn't matter if you lose the read cache in RAM - and the OS is going to keep a copy there as long as it can anyway. The point of SSD caching of journals/writes is that it survives a reboot. If you have a lot more SSD than spare RAM it might save a few seeks as a side effect but why not just add RAM if that matters? -- Les Mikesell lesmikesell at gmail.com