Messages in this thread | | | Date | Thu, 12 Feb 2004 10:15:23 GMT | From | John Bradford <> | Subject | Re: ext2/3 performance regression in 2.6 vs 2.4 for small interl |
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Quote from Giuliano Pochini <pochini@shiny.it>: > > On 12-Feb-2004 Andrea Arcangeli wrote: > > > the main difference is that 2.4 isn't in function of time, it's in > > function of requests, no matter how long it takes to write a request, > > so it's potentially optimizing slow devices when you don't care about > > latency (deadline can be tuned for each dev via > > /sys/block/*/queue/iosched/). > > IMHO it's the opposite. Transfer speed * seek time of some > slow devices is lower than fast devices. For example: > > Hard disk raw speed= 40MB/s seek time = 8ms > MO/ZIP raw speed= 3MB/s seek time = 25ms > > One seek of HD costs about 320KB, while on a slow drive it's > only 75KB.
Hmmm, but I would imagine that most hard disks have much larger caches than are popular on removable cartridge drives...
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