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Subject: What disk drive

What disk drive

From: BlueChip <cs_bluechip_at_webtribe.net>
Date: 2004-12-13

I hope this helps understand the meaning of drive specs....

1. Spin Up Time
The time the drive takes to spin up to working speed from stopped.

2. Seek Time
The average time taken by the drive to move the read-head to the correct
area of the disk platter.

3. Latency
The average time taken before the disk turns such that the requested data
is under the read-head.

4. Internal Data Transfer Rate
The speed at which data is moved from the disk platter to the onboard
memory (aka "cache")
...after it has been found (see 2 & 3).

5. External Data Transfer Rate
The speed at which data is given to the host device (ie. pc or jukebox
motherboard)

===

You need to consider two thing when putting a drive in a jukebox:

1. Will it read data off fast enough to play?
Uncompressed CD music is 150KB/Sec ...same speed as a 1x CD player.
By example, the Fujitsu you mention (I presume "MHT2080AT") is rated at 100MB

By means of a more direct answer ...the Fujitsu would be able to play two
hundred and fifty --extreme MP3's simultaneously (maybe only 150
considering Seek Time and Latency.)

2. Is lots of cache beneficial?
It has been said that it is impossible for Rockbox to use the Hard Drive
Cache without an unnacceptable power drain on the batteries.

So as far as Rockbox is concerned (unless anybody ever works a way around
the issue) the Cache is a useless feature to have on your drive.
...2MB will go as UNUSED as 1MB or 32MB.

BC

At 18:21 13/12/2004, you wrote:
> > why not upgrade your archos to 80 or even 100 gigs?
> > i done it a while ago & it's not very difficult.
>
>Got a Jukebox V2 and this thread got me thinking about upgrading the disk.
>
>I can see Fujitsu (4200rpm, 2Mb cache) and Hitachi/IBM (5400rpm, 8Mb
>cache) 80Gbdrives and also a Fujitsu (4200rpm, 8Mb cache) 100Gb unit.
>
>The 100Gb drive is 1 1/3 times the cost of the 80Gb drives so I'll opt for
>80Gb. Any comments regarding the pro/cons of the spin rates - I'd assume a
>slower spin rate would use less battery power but is 4200rpm fast enough
>for an Archos playing VBR (lame -extreme) MP3 files (especially as the
>cache is smaller)?
>
>Any recommendations/preferences?

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Received on Mon Dec 13 21:30:05 2004


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