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geekhack Community => Off Topic => Topic started by: tp4tissue on Fri, 22 April 2022, 18:12:08

Title: Interesting drive behavior
Post by: tp4tissue on Fri, 22 April 2022, 18:12:08
Why does it have a ramp like this at the beginning and end ?

did they cheap out on the head controller, so it's too fast at the beginning to track, and too slow at the end ?

start ramp from 150mb/s to 190mb/s

tail ramp from 100mb/s down to 83mb/s


[attachimg=1]
Title: Re: Interesting drive behavior
Post by: Leslieann on Fri, 22 April 2022, 21:48:11
Spinner?
Probably moving from outer area to inner, as well as having to frag more and more as it goes along.
Title: Re: Interesting drive behavior
Post by: tp4tissue on Fri, 22 April 2022, 21:53:27
Spinner?
Probably moving from outer area to inner, as well as having to frag more and more as it goes along.

But this was continuous write, end to end.
Title: Re: Interesting drive behavior
Post by: Leslieann on Fri, 22 April 2022, 23:40:06
Not sure how that matters.
Title: Re: Interesting drive behavior
Post by: tp4tissue on Sat, 23 April 2022, 10:36:53
tested read only, end to end.

no dip. this is full read, not sampled

[attachimg=1]
Title: Re: Interesting drive behavior
Post by: Leslieann on Sat, 23 April 2022, 11:50:29
Looks like it tapered off to me.
Curve looks almost identical, different scale, but similar curve.
Title: Re: Interesting drive behavior
Post by: tp4tissue on Sat, 23 April 2022, 12:02:58

yea, curve is the same, but no weird ramp


[attachimg=1]

[attachimg=2]

(https://i.imgur.com/hVaXskJ.gif)
Title: Re: Interesting drive behavior
Post by: Leslieann on Sat, 23 April 2022, 13:45:19
Minor stuff like that can be anything.
Some other system causing lag but my guess is that it was mapping out where to place all of the data.
Title: Re: Interesting drive behavior
Post by: yui on Fri, 29 April 2022, 14:48:45
isn't the ramp cache optimization? or the drive spinning up from sleep and then slowing down at the end of copy? or if it is a magnetic shingle drive it will need to write 2 track at once to be fast, so at the end it could be that? all that is assuming hard drive, on and ssd there is not telling what the controller and windows are doing :)
i am throwing those out there because i am quite curious too
Title: Re: Interesting drive behavior
Post by: Leslieann on Fri, 29 April 2022, 18:13:53
Shingle wouldn't write anywhere near these speeds, usually 1/4 normal speeds.

Could be drive spinup, I assumed the drive was already spinning (I never let mine spin down).