I have never seen a single 2.5" drive of the kind you get in cheapo
little portable enclosures get above 40MB/s on ANY connection. Be it
USB, 400 or 800 M/bit firewire. They are all a sack when it comes to
transfer rates but a million cheap arsed producers can't be wrong!
Rupert Watson
+44 7787 554 801
www.root6.com
-----Original Message-----
From: Avid-L2@yahoogroups.com [mailto:Avid-L2@yahoogroups.com] On Behalf
Of David Ross
Sent: 12 May 2011 17:35
To: Avid-L2@yahoogroups.com
Subject: Re: [Avid-L2] External Drive for media w/ MacBook Pro
Then why do I get about twice the transfer rates from the same drive
when I use FW800, compared to USB? Same drive, same computer, same
files, different cables. The drive is absolutely NOT slower than the
connection.
480 Mb/s is "top speed" for USB 2, the sustained transfer rate you get
will depend on the state of the drive (i.e. how full/fragmented it is)
and what you are copying (i.e. lots of little files or one big file.)
190 Mb/s does not surprise me at all. FW400 theoretically has slower
speed (400 Mb/s vs USB's 480 Mb/s), but, because it's designed for
sustained transfers, will actually give better speed when you're moving
large amounts of data around (i.e. it's better for editing.)
Further reading:
http://en.wikipedia.org/wiki/Usb#USB_2.0
http://en.wikipedia.org/wiki/Sata#Revisions
D.
On 12 May 2011 17:09, bouke <bouke@editb.nl> wrote:
>
>
> David,
> Explain me this:
> I'm doing a copy of 500 gig right now to a similar drive over USB.
> I see transfer rates of about 190 Mb/s.
> And that is 'real world' (if there is a reality in my studio, still
> not
> sure)
> Now if USB is capable of 480 Mb/s, why am i running less than half the
> speed?
>
> I can answer that, simply cause the drive is slower than the
connection.
>
> Now i am the first to admit that using a 99 USD drive is not the way
to go.
> (My 6 TB storage set me back 8000 USD, but i have shared storage and
> Raid
> protected)
>
> But again, the physical drive itself is the bottleneck, not the
connection.
> No matter if you put a SATA_16 2040 UltraWide Fast 256 bits
> "thunderbold widowmaker" connector on it.
>
> But it can also be my building is on old Indian burial grounds, hence
> i don't get higher speeds than 25 MB / sec on any single drive.
> (again, that is real world here, not specs...)
>
> Bouke (Who has to change a few lightbulbs now)
>
>
> VideoToolShed
> van Oldenbarneveltstraat 33
> 6512 AS NIJMEGEN
> The Netherlands
> +31 24 3553311
> www.videotoolshed.com
> For large files:
> http://dropbox.yousendit.com/BoukeVahl998172
>
> ----- Original Message -----
> From: "David Ross" <speckydave@gmail.com>
> To: <Avid-L2@yahoogroups.com>
> Sent: Thursday, May 12, 2011 5:40 PM
> Subject: Re: [Avid-L2] External Drive for media w/ MacBook Pro
>
> > Bouke,
> > Maybe I'm missing your point, but I I don't see how you can say that
> > USB is faster than the drive can perform.
> >
> > This drive is USB 2, which has a top transfer speed of 480 Mb/s.
> > Even if the drive here is only an old revison 1 SATA, that's still
> > 1.5 Gb/s, which is more than three times faster. More likely that
> > it's a revision 3 SATA, which would give it 6 Gb/s, even faster than
> > USB 3 (which is an option for this drive if you buy the adapter,
> > though won't be supported on a MBP.)
> >
> > Personally, I would always try to avoid USB for editing from, though
> > it's probably fine for simple low-res edits. For this kind of
> > budget, you'd be much better off with a Firewire 800 drive, which
> > would give about twice the transfer speed for very little extra
money.
> >
> > D.
> >
> >
> > On 12 May 2011 14:42, bouke <bouke@editb.nl> wrote:
> >>
> >>
> >
> >> even if it is USB, USB is faster than the drive can perform.
> >
>
>
>
[Non-text portions of this message have been removed]
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