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Orca

access time => seek time ?

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I queried the average seek time I measured for my 2-head 6Y080L0 drive with Maxtor: 13.7ms - 4.2ms (latency) = 9.5ms seek time ?

They said: no - 13.7 - 4.2 (latency) - 0.1 (BIOS/driver overhead) - 0.5 (settle time) = 8.9ms

:?:

Ok, I can understand allowing for the BIOS/driver overhead, although with modern systems I rather doubt that it makes a measurable difference (they actually said <0.1ms, so allow 0.1).

But taking of 0.5ms for "settle time" ?

This seems a bit odd - using this formula would give a 7.8ms seek time for the 3-head 6Y080L0.

Surely the "settling" is part of the "seek" ?

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Guest Eugene

The definition varies from manufacturer to manufacturer and from time to time. For our purposes, we consider seek time = access time - latency. Everything else is trivial, and many drives do hit the mark under this more stringent definition.

Regards,

Eugene

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looks like maxtor is gay...

seek time = the time from when the HDD is given the read/write command to the time it's heads are ready to read or write... note that I said ready to read or write... The drive still has to wait for a spot on the disk to read from or write to to pass under it... (rotational latency)

In any event, the head can settle while the part of the disk where the data is can spin around to meet the head.. (the two happen in paralell) so I dont see why you have to add any time for settling... it should just be included in the seek time if it hurts performance...

basiclly, I think maxtor is cheating (lying) and putting down false specs... som other manufacturers have also been a little overly optimistic about their drives performance... However a 5-10% figure is getting to be a little excessive.

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That loose defination of seek time (i.e. not including the settle) is meaningless.

When asked how long it takes to get home from work, I wouldn't say "5 minutes to walk to my car, 3 minutes to drive to the highway, 10 minutes on the highway, 5 from the highway to my house, and 1 to get out of my car to walk into my house." It's silly to break it up that way. Truth is, it takes 24 minutes. If I take a different route that shaves one minute off my highway time, but adds one minute to my city driving, I wouldn't exclaim that I "dropped my highway time to just 9 minutes!". Claiming a fast seek without accounting for the settle is essentially the mental exercise.

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I thought the "looks like maxtor is gay" line was the most eloquent :D

In this modern world we're not meant to say things like that, but you're right, it does look like they're gay. Fiddling the numbers, the rotten sods.

Dave

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Of course, the fact that they have changed the seek spec. on the website and datasheet from <9ms to <=9.4ms is purely co-incidental :wink:

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i love how they include the clause in the specs that "these specs are subject to change at any time without notice".... really gives you a sense that these guys are honest.

But, I guess that's a standard clause for just about every business spec sheet.... pretty sad.

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