Messages in this thread | | | Date | Tue, 25 May 2004 11:02:14 -0600 | From | "Eric D. Mudama" <> | Subject | Re: Linux Kernel 2.6.6 IDE shutdown problems. |
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On Tue, May 25 at 11:05, Giuliano Pochini wrote: > > >On Mon, 24 May 2004, Eric D. Mudama wrote: > >> Picture a nice fast drive doing 100 writes/second to the media... if >> you give it over 200 writes at a time, it'll occupy your 2 seconds. >> Newer drives with 8MB or larger buffers are certainly capable of >> caching a lot more than 200 writes... > >Quite unlikely. Usually disks have a big cache but it can hold a very >limited number of blocks. 8MB of cache is probably divided in 8 blocks >of 1MB each.
Sorry, but that isn't true, unless some company is just plain stupid.
Everyone has different metrics for cache granularity based on their cache architecture, but I can assure you that 8x 1MB segments is off by 1-2 orders of magnitude, and has been for years.
In practice, depending on the workload, there may appear to only be 8 active segments as drives today can merge cache segments or other similar things (architectually dependant), but the worst-case (best case?) is significantly more.
--eric
-- Eric D. Mudama edmudama@mail.bounceswoosh.org
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