Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > Computer Information > SCSI v USB Scanners?

Reply
Thread Tools

SCSI v USB Scanners?

 
 
John
Guest
Posts: n/a
 
      08-01-2004
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


 
Reply With Quote
 
 
 
 
Mac McDougald
Guest
Posts: n/a
 
      08-01-2004
In article <(E-Mail Removed)>, http://www.velocityreviews.com/forums/(E-Mail Removed)
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
 
Reply With Quote
 
 
 
 
David Littlewood
Guest
Posts: n/a
 
      08-02-2004
In article <(E-Mail Removed)>, Mac McDougald
<(E-Mail Removed)> writes
>In article <(E-Mail Removed)>, (E-Mail Removed)
>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
 
Reply With Quote
 
Julian Knight
Guest
Posts: n/a
 
      08-02-2004
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=(E-Mail Removed), Yahoo!=knighjm
 
Reply With Quote
 
Julian Knight
Guest
Posts: n/a
 
      08-02-2004
From Mac McDougald on 02/Aug/2004 00:55:

> In article <(E-Mail Removed)>, (E-Mail Removed)
> 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=(E-Mail Removed), Yahoo!=knighjm
 
Reply With Quote
 
Jim Berwick
Guest
Posts: n/a
 
      08-02-2004
Julian Knight <news003@[127.0.0.1]> wrote in news:410df700$0$25120
$(E-Mail Removed):

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


What PCI/PCI Express issues?
 
Reply With Quote
 
Glenn
Guest
Posts: n/a
 
      08-02-2004
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.

 
Reply With Quote
 
Thor
Guest
Posts: n/a
 
      08-02-2004
> > 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.


 
Reply With Quote
 
Ionizer
Guest
Posts: n/a
 
      08-02-2004
"SWINGERS" <(E-Mail Removed)> wrote in message
news:AerPc.36$Iy.14@trndny07...
>
>
> --
>
> Looking for other swingers?


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


 
Reply With Quote
 
David R
Guest
Posts: n/a
 
      08-02-2004
David Littlewood <(E-Mail Removed)> wrote in message news:<(E-Mail Removed)>...
> In article <(E-Mail Removed)>, Mac McDougald
> <(E-Mail Removed)> writes
> >In article <(E-Mail Removed)>, (E-Mail Removed)
> >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.
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Re: USB issue ... some USB 2 ports working only in USB 1 mode hungsolo2005@yahoo.com A+ Certification 0 06-14-2006 07:26 PM
Driver for Microtech scsi to usb adaptor ardnasx1 Computer Support 2 04-28-2006 06:09 PM
Which is faster? A USB printer or a SCSI printer? dandelion A+ Certification 5 04-01-2006 09:28 PM
ONLY USB Floppy, how to install SCSI driver? =?Utf-8?B?U3VucmlzZVNPTA==?= Windows 64bit 1 08-23-2005 06:23 PM
Seagate Cheetah 15K.4 ST3146854LC SCSI Hard Drive @ InsaneTe Silverstrand Front Page News 0 07-21-2005 02:13 PM



Advertisments