Difference betw. 2MB and 8MB buffer for backup HD

4 Mar 2005 2:42 PM

jack

I know, I know... about 6 MB.
I was looking at a USB HD enclosure to try to deal with a separate HD
problem, and found that CompUSA has a deal on a Hitachi Deskstar 7k250
160 GB HD, with a free enclosure, for $60 (after rebates). Now, this
is a Parallel ATA with only a 2MB buffer. My thoughts are to use this
as a backup drive. How much of a difference will the smaller buffer be
for this use? Also, the enclosure is USB 2.0; no firewire, though from
what I've read if it's Firewire 400 it's no faster than USB 2.0. Or is
that wrong, too? TIA!

4 Mar 2005 3:39 PM

S.Heenan

jack wrote:

> I know, I know... about 6 MB.
> I was looking at a USB HD enclosure to try to deal with a separate HD
> problem, and found that CompUSA has a deal on a Hitachi Deskstar 7k250
> 160 GB HD, with a free enclosure, for $60 (after rebates). Now, this
> is a Parallel ATA with only a 2MB buffer. My thoughts are to use this
> as a backup drive. How much of a difference will the smaller buffer be
> for this use? Also, the enclosure is USB 2.0; no firewire, though from
> what I've read if it's Firewire 400 it's no faster than USB 2.0. Or is
> that wrong, too? TIA!

In practical terms, not much of a difference. If given a choice, at the same
price point, opt for the 8MB model, but at $.38/GB the 7K250 sounds very
appealing.

USB2.0 480Mbits/sec

IEEE 1394 400Mbits/sec

--
" No, it means that MS has found ways to incress revinue dispite
declining groth of market share." - Ralph, resident Hooked on
Phonics/economics expert

4 Mar 2005 8:06 PM

jack

Show quote Hide quote

On Fri, 04 Mar 2005 15:39:30 GMT, "S.Heenan" <shee***@wahs.ac> wrote:

>jack wrote:
>> I know, I know... about 6 MB.
>> I was looking at a USB HD enclosure to try to deal with a separate HD
>> problem, and found that CompUSA has a deal on a Hitachi Deskstar 7k250
>> 160 GB HD, with a free enclosure, for $60 (after rebates). Now, this
>> is a Parallel ATA with only a 2MB buffer. My thoughts are to use this
>> as a backup drive. How much of a difference will the smaller buffer be
>> for this use? Also, the enclosure is USB 2.0; no firewire, though from
>> what I've read if it's Firewire 400 it's no faster than USB 2.0. Or is
>> that wrong, too? TIA!
>
>
>In practical terms, not much of a difference. If given a choice, at the same
>price point, opt for the 8MB model, but at $.38/GB the 7K250 sounds very
>appealing.
>
>USB2.0 480Mbits/sec
>
>IEEE 1394 400Mbits/sec

Thanks for the feedback. Unfortunately, already a moot point, as
they're sold out. Online they said they were in stock, but turns out
the website is 1-day delayed in the store stock, and they sold out
yesterday. Aarrgghh...

4 Mar 2005 11:39 PM

kony

On Fri, 04 Mar 2005 14:42:19 GMT, jack <a@b.com> wrote:

>I know, I know... about 6 MB.
>I was looking at a USB HD enclosure to try to deal with a separate HD
>problem, and found that CompUSA has a deal on a Hitachi Deskstar 7k250
>160 GB HD, with a free enclosure, for $60 (after rebates). Now, this
>is a Parallel ATA with only a 2MB buffer. My thoughts are to use this
>as a backup drive. How much of a difference will the smaller buffer be
>for this use? Also, the enclosure is USB 2.0; no firewire, though from
>what I've read if it's Firewire 400 it's no faster than USB 2.0. Or is
>that wrong, too? TIA!

1) Firewire has lower specs on paper but it use is
typically as fast or faster.

2) However, either are slower than the potential of a
modern drive. If the drive were to be used inside a system
attached to SATA or PATA, SCSI, etc, the larger buffer would
make more of a difference. In an external enclosure, the
USB chips on both ends of the cable will be the
bottleneck(s), not the drive buffer size... might still make
a tiny difference but relatively insignificant for backup
and personal, general filestores.

5 Mar 2005 5:53 AM

jack

On Fri, 04 Mar 2005 23:39:47 GMT, kony <spam@spam.com> wrote:

Show quoteHide quote

>On Fri, 04 Mar 2005 14:42:19 GMT, jack <a@b.com> wrote:
>
>>I know, I know... about 6 MB.
>>I was looking at a USB HD enclosure to try to deal with a separate HD
>>problem, and found that CompUSA has a deal on a Hitachi Deskstar 7k250
>>160 GB HD, with a free enclosure, for $60 (after rebates). Now, this
>>is a Parallel ATA with only a 2MB buffer. My thoughts are to use this
>>as a backup drive. How much of a difference will the smaller buffer be
>>for this use? Also, the enclosure is USB 2.0; no firewire, though from
>>what I've read if it's Firewire 400 it's no faster than USB 2.0. Or is
>>that wrong, too? TIA!
>
>1) Firewire has lower specs on paper but it use is
>typically as fast or faster.
>
>2) However, either are slower than the potential of a
>modern drive. If the drive were to be used inside a system
>attached to SATA or PATA, SCSI, etc, the larger buffer would
>make more of a difference. In an external enclosure, the
>USB chips on both ends of the cable will be the
>bottleneck(s), not the drive buffer size... might still make
>a tiny difference but relatively insignificant for backup
>and personal, general filestores.

Thanks for the clarifications. Now if I could just find one in-stock!

4 Mar 2005 11:58 PM

DaveW

USB 2.0= 480 Mbps.

Firewire 400= 400 Mbps.

--
DaveW

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"jack" <a@b.com> wrote in message
news:7msg21hhjtb6r66612j0fk976uh004gu8l@4ax.com...
>I know, I know... about 6 MB.
> I was looking at a USB HD enclosure to try to deal with a separate HD
> problem, and found that CompUSA has a deal on a Hitachi Deskstar 7k250
> 160 GB HD, with a free enclosure, for $60 (after rebates). Now, this
> is a Parallel ATA with only a 2MB buffer. My thoughts are to use this
> as a backup drive. How much of a difference will the smaller buffer be
> for this use? Also, the enclosure is USB 2.0; no firewire, though from
> what I've read if it's Firewire 400 it's no faster than USB 2.0. Or is
> that wrong, too? TIA!