Pros and Cons of amd64 (versus i386).

[Chris H.]

Quoting "Matthew D. Fuller" <fullermd at over-yonder.net>:

> On Sat, Apr 08, 2006 at 06:00:56PM -0600 I heard the voice of
> Scott Long, and lo! it spake thus:
>>
>> Modern disks (I don't know how to define a cutoff to this term,
>> unfortunately) definitely put more bits onto the outer rim of the
>> platter than the inner rim.
>
> Pretty much any disk you'd currently find, I'd say.
>
> diskinfo -t won't run through on my 4 or 2 gigs ("disk too small for
> test"  :), but on my 9 gigger:
>
> Transfer rates:
>        outside:       102400 kbytes in   5.215159 sec =    19635 kbytes/sec
>        middle:        102400 kbytes in   6.268067 sec =    16337 kbytes/sec
>        inside:        102400 kbytes in   8.237962 sec =    12430 kbytes/sec
>
> da4 at ahc2 bus 0 target 5 lun 0
> da4: <IBM DNES-309170W SAH0> Fixed Direct Access SCSI-3 device
> da4: 40.000MB/s transfers (20.000MHz, offset 31, 16bit), Tagged 
> Queueing Enabled
> da4: 8748MB (17916240 512 byte sectors: 255H 63S/T 1115C)

Well, as long as we're at it:


        512             # sectorsize
        15728640000     # mediasize in bytes (15G)
        30720000        # mediasize in sectors
        1912            # Cylinders according to firmware.
        255             # Heads according to firmware.
        63              # Sectors according to firmware.

Seek times:
        Full stroke:      250 iter in   4.058565 sec =   16.234 msec
        Half stroke:      250 iter in   3.249077 sec =   12.996 msec
        Quarter stroke:   500 iter in   5.544275 sec =   11.089 msec
        Short forward:    400 iter in   2.595878 sec =    6.490 msec
        Short backward:   400 iter in   2.547004 sec =    6.368 msec
        Seq outer:       2048 iter in   0.486885 sec =    0.238 msec
        Seq inner:       2048 iter in   0.500109 sec =    0.244 msec
Transfer rates:
        outside:       102400 kbytes in   5.517532 sec =    18559 kbytes/sec
        middle:        102400 kbytes in   6.233613 sec =    16427 kbytes/sec
        inside:        102400 kbytes in   8.044342 sec =    12729 kbytes/sec


at ahc0 bus 0 target 1 lun 0
<WDIGTL WDE18300 ULTRA2 1.30> Fixed Direct Access SCSI-2 device Serial 
Number WS7060096840
40.000MB/s transfers (20.000MHz, offset 31, 16bit)

Interesting to note (to me anyway) is my SCSI reports fastest on the outside
whereas my (earlier reported) ATA reports faster in the center (middle).

--Chris H.

>
>
> --
> Matthew Fuller     (MF4839)   |  fullermd at over-yonder.net
> Systems/Network Administrator |  http://www.over-yonder.net/~fullermd/
>           On the Internet, nobody can hear you scream.
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Linux:
As OS for users who think their using UNIX.


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