«

Hello

A lot of people seem to recommend SCSI connected scanners over USB
ones, but isn't USB faster than SCSI?

Maybe I'm wrong but I thought the speeds for the two standards were as
follows:

USB2 480 Mbps
SCSI-3 Ultra 20 MBps

I thought that even USB 1 was 40 Mbps? So wouldn't that have been
faster than the latest SCSI-3 Ultras speed can muster?

Or perhaps the difference comes with the controllers and the SCSI just
has better controllers and drivers, and the USB takes up too much
resources? Or perhaps the USB can't achieve the top speeds it is
supposed to be capable of, but the SCSI can?

I'm a tad confused on this, but it does seem from what people say in
comp.periphs.scanners that SCSI is faster?

Thanks for any clarification on this

John

In article <>,
says...
> Hello
>
> A lot of people seem to recommend SCSI connected scanners over USB
> ones, but isn't USB faster than SCSI?
>
> Maybe I'm wrong but I thought the speeds for the two standards were as
> follows:
>
> USB2 480 Mbps
> SCSI-3 Ultra 20 MBps
>
> I thought that even USB 1 was 40 Mbps? So wouldn't that have been
> faster than the latest SCSI-3 Ultras speed can muster?
>
> Or perhaps the difference comes with the controllers and the SCSI just
> has better controllers and drivers, and the USB takes up too much
> resources? Or perhaps the USB can't achieve the top speeds it is
> supposed to be capable of, but the SCSI can?
>
> I'm a tad confused on this, but it does seem from what people say in
> comp.periphs.scanners that SCSI is faster?
>
> Thanks for any clarification on this
>
> John

Think you have megaBITS (Mb) and megaBYTES (MB) mixed here.
Here's a pretty good chart of USB/SCSI/Firewire speeds:
http://www.macspeedzone.com/archive/...wirevsscsi.gif

Few if any consumer grade scanners made with SCSI interface now anyway,
so fairly moot, unless you're using older ones (like me)...


Mac

In article <>, Mac McDougald
<> writes
>In article <>,
>says...
>> Hello
>>
>> A lot of people seem to recommend SCSI connected scanners over USB
>> ones, but isn't USB faster than SCSI?
>>
>> Maybe I'm wrong but I thought the speeds for the two standards were as
>> follows:
>>
>> USB2 480 Mbps
>> SCSI-3 Ultra 20 MBps
>>
>> I thought that even USB 1 was 40 Mbps? So wouldn't that have been
>> faster than the latest SCSI-3 Ultras speed can muster?
>>
>> Or perhaps the difference comes with the controllers and the SCSI just
>> has better controllers and drivers, and the USB takes up too much
>> resources? Or perhaps the USB can't achieve the top speeds it is
>> supposed to be capable of, but the SCSI can?
>>
>> I'm a tad confused on this, but it does seem from what people say in
>> comp.periphs.scanners that SCSI is faster?
>>
>> Thanks for any clarification on this
>>
>> John
>
>Think you have megaBITS (Mb) and megaBYTES (MB) mixed here.
>Here's a pretty good chart of USB/SCSI/Firewire speeds:
>http://www.macspeedzone.com/archive/...wirevsscsi.gif
>
>Few if any consumer grade scanners made with SCSI interface now anyway,
>so fairly moot, unless you're using older ones (like me)...
>
The really important difference IMO is that SCSI peripherals are an
utter pain in the backside to get working (and the pain increases as a
high power of the number you daisy-chain), whereas every USB device I
have ever used has connected and worked first time right out of the box.
--
David Littlewood

From John on 02/Aug/2004 00:12:

> Hello
>
> A lot of people seem to recommend SCSI connected scanners over USB
> ones, but isn't USB faster than SCSI?
>
> Maybe I'm wrong but I thought the speeds for the two standards were as
> follows:
>
> USB2 480 Mbps
> SCSI-3 Ultra 20 MBps
>
> I thought that even USB 1 was 40 Mbps? So wouldn't that have been
> faster than the latest SCSI-3 Ultras speed can muster?
>
> Or perhaps the difference comes with the controllers and the SCSI just
> has better controllers and drivers, and the USB takes up too much
> resources? Or perhaps the USB can't achieve the top speeds it is
> supposed to be capable of, but the SCSI can?
>
> I'm a tad confused on this, but it does seem from what people say in
> comp.periphs.scanners that SCSI is faster?
>
> Thanks for any clarification on this
>
> John
>
>
Don't forget that to achieve 480Mbps, USB has to make very heavy use of the PC's
CPU unlike SCSI and Firewire. This is probably OK for scanning but often
catches people out for Video and other more intensive work.

--
Julian Knight, http://www.knightnet.org.uk/
Sheffield, United Kingdom
Security, Directory, Messaging, Network & PC Consultant
Instant Messaging:Jabber=, Yahoo!=knighjm

From Mac McDougald on 02/Aug/2004 00:55:

> In article <>,
> says...
>
>>Hello
>>
>>A lot of people seem to recommend SCSI connected scanners over USB
>>ones, but isn't USB faster than SCSI?
>>
>>Maybe I'm wrong but I thought the speeds for the two standards were as
>>follows:
>>
>>USB2 480 Mbps
>>SCSI-3 Ultra 20 MBps
>>
>>I thought that even USB 1 was 40 Mbps? So wouldn't that have been
>>faster than the latest SCSI-3 Ultras speed can muster?
>>
>>Or perhaps the difference comes with the controllers and the SCSI just
>>has better controllers and drivers, and the USB takes up too much
>>resources? Or perhaps the USB can't achieve the top speeds it is
>>supposed to be capable of, but the SCSI can?
>>
>>I'm a tad confused on this, but it does seem from what people say in
>>comp.periphs.scanners that SCSI is faster?
>>
>>Thanks for any clarification on this
>>
>>John
>
>
> Think you have megaBITS (Mb) and megaBYTES (MB) mixed here.
> Here's a pretty good chart of USB/SCSI/Firewire speeds:
> http://www.macspeedzone.com/archive/...wirevsscsi.gif
>
> Few if any consumer grade scanners made with SCSI interface now anyway,
> so fairly moot, unless you're using older ones (like me)...
>
>
> Mac

Anyone had any joy with a SCSI->USB converter? I currently only have an ISA SCSI
card which doesn't fit in my newer computers and was thinking this would be the
best bet (avoiding the PCI/PCI Express/... issues altogether!).

--
Julian Knight, http://www.knightnet.org.uk/
Sheffield, United Kingdom
Security, Directory, Messaging, Network & PC Consultant
Instant Messaging:Jabber=, Yahoo!=knighjm

Julian Knight <news003@[127.0.0.1]> wrote in news:410df700$0$25120
$:

> best bet (avoiding the PCI/PCI Express/... issues altogether!).

What PCI/PCI Express issues?

Julian Knight wrote:
> From John on 02/Aug/2004 00:12:
>
>> Hello
>>
>> A lot of people seem to recommend SCSI connected scanners over USB
>> ones, but isn't USB faster than SCSI?
>>
>> Maybe I'm wrong but I thought the speeds for the two standards were as
>> follows:
>>
>> USB2 480 Mbps
>> SCSI-3 Ultra 20 MBps
>> I thought that even USB 1 was 40 Mbps? So wouldn't that have been
>> faster than the latest SCSI-3 Ultras speed can muster?
>>
>> Or perhaps the difference comes with the controllers and the SCSI just
>> has better controllers and drivers, and the USB takes up too much
>> resources? Or perhaps the USB can't achieve the top speeds it is
>> supposed to be capable of, but the SCSI can?
>>
>> I'm a tad confused on this, but it does seem from what people say in
>> comp.periphs.scanners that SCSI is faster?
>>
>> Thanks for any clarification on this
>>
>> John
>>
>>
> Don't forget that to achieve 480Mbps, USB has to make very heavy use of
> the PC's CPU unlike SCSI and Firewire. This is probably OK for scanning
> but often catches people out for Video and other more intensive work.
>

USB definately uses a lot of CPU power. When I have my USB scanner
driver GUI opened, CPU usage is 50% and CPU temps jump to about 50 C.

Julian, are you looking for a PCI SCSI card? I have one just sitting
here. I used it for optical drives, but I have gone IDE. I haven't
used it since August 2002, I assume it works, it's been boxed up since then.

> > Don't forget that to achieve 480Mbps, USB has to make very heavy use of
> > the PC's CPU unlike SCSI and Firewire. This is probably OK for scanning
> > but often catches people out for Video and other more intensive work.
> >
>
> USB definately uses a lot of CPU power. When I have my USB scanner
> driver GUI opened, CPU usage is 50% and CPU temps jump to about 50 C.

I think much depends on the USB chipset in particular, not necessarily the
spec. I just transferred a 500MB file from my external hi-speed USB 2.0
harddrive to my local harddrive, and my CPU utilization averaged around
15-18% throughout. I'm using a USB 2.0 interface card with an NEC controller
chip.

"SWINGERS" <> wrote in message
news:AerPc.36$Iy.14@trndny07...
>
>
> --
>
> Looking for other swingers?

Spam report id 1151167261 sent to: abuse @ verizon.net

David Littlewood <> wrote in message news:<>...
> In article <>, Mac McDougald
> <> writes
> >In article <>,
> >says...
> >> Hello
> >>
> >> A lot of people seem to recommend SCSI connected scanners over USB
> >> ones, but isn't USB faster than SCSI?
> >>
> >> Maybe I'm wrong but I thought the speeds for the two standards were as
> >> follows:
> >>
> >> USB2 480 Mbps
> >> SCSI-3 Ultra 20 MBps
> >>
> >> I thought that even USB 1 was 40 Mbps? So wouldn't that have been
> >> faster than the latest SCSI-3 Ultras speed can muster?
> >>
> >> Or perhaps the difference comes with the controllers and the SCSI just
> >> has better controllers and drivers, and the USB takes up too much
> >> resources? Or perhaps the USB can't achieve the top speeds it is
> >> supposed to be capable of, but the SCSI can?
> >>
> >> I'm a tad confused on this, but it does seem from what people say in
> >> comp.periphs.scanners that SCSI is faster?
> >>
> >> Thanks for any clarification on this
> >>
> >> John
> >
> >Think you have megaBITS (Mb) and megaBYTES (MB) mixed here.
> >Here's a pretty good chart of USB/SCSI/Firewire speeds:
> >http://www.macspeedzone.com/archive/...wirevsscsi.gif
> >
> >Few if any consumer grade scanners made with SCSI interface now anyway,
> >so fairly moot, unless you're using older ones (like me)...
> >
> The really important difference IMO is that SCSI peripherals are an
> utter pain in the backside to get working (and the pain increases as a
> high power of the number you daisy-chain), whereas every USB device I
> have ever used has connected and worked first time right out of the box.

I have never had any problems with SCSI devices. My experiences have
found them to be fast, reliable, and easy to configure. I've had
drives and scanners running from Windows 98 to Windows XP.