A computer components & hardware forum. HardwareBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » HardwareBanter forum » General Hardware & Peripherals » Storage (alternative)
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Building a new system: SCSI or IDE?



 
 
Thread Tools Display Modes
  #11  
Old July 28th 03, 03:33 PM
Folkert Rienstra
external usenet poster
 
Posts: n/a
Default


"Gareth Church" wrote in message
"Folkert Rienstra" wrote in message ...
Although SCSI has always been considered superior, IDE performance
has improved drastically in recent years,


So has SCSI's.


No where near to the same extent.


Ofcourse it has.

From a performance point of view, now that
you can use IDE RAID, SCSI doesn't offer much more.


SCSI RAID, obviously.

From a reliability point of view SCSI is obviously still ahead,


Nope. There is where ATA indeed made good.

but IDE has come a long way. Given the substantial price dif-
ference, you have to consider whether SCSI is really worth it.


Ofcourse, but that goes for every component on the system.

For a home system like the OP is talking about, though,
SCSIs negatives (namely price) far outweigh it's benefits.


Same can be said for processors, perhaps even more so.
However, processors are much sexier, for some stupid reason or other.


is becoming the standard,


Nope.


I don't think he meant standard in any official sense


IDE always was standard on a PC, it's not 'becoming' standard.
SCSI always has been for Servers and highend Workstations.

(ie. that it is planned to phase out SCSI and replace it with IDE),
but SCSIs market is certainly shrinking.


It isn't. Maybe it will with SATA and SAS on the horizon.
However for SATA to become external you need SAS.

I would strongly consider using IDE drives for some servers these days,


That's entry level server.

and I'm not alone.


IDE is fine for central backup. It isn't for multiuser/multitasking.
IDE is a goner. SATA *may* take inroads in the higher end workstation
business and parts of the server business by introducing professional
grade SATA drives like the current WD RAPTOR.

SCSIs niche will continue to be infiltrated by IDE, meaning that
prices for SCSI will rise and support and innovation will decrease.


IDE is nearly dead, SCSI will soon be. SAS and SATA will take over.
When SATA starts to invade the server business too much, SAS will
have to come down in price. However, if SAS can sustain market share
by taking over some Fiber Channel business, that may not happen.


Gareth

  #12  
Old July 28th 03, 07:38 PM
Rod Speed
external usenet poster
 
Posts: n/a
Default


Bob WIllard wrote in
message ...
Rod Speed wrote:


Even SCSI doesnt allow the use of all 4 drives simultaneously anyway.


Sure it does. SCSI allows all drives to be used simultaneously;


Wrong. You cant simultaneously transfer data from all
drives literally simultaneously, there is still only one bus.

What SCSI can do is use the bus for another drive when
one of them is seeking etc. Thats not the same thing as
simultaneous data transfer from all drives at once.

up to 7 HDs on a narrow bus and up to 15 HDs on a wide bus.
E.g., SCSI allows the initiator (the Host Adapter) to issue a
read command to each target (HD) and then disconnect from
the SCSI bus; each HD may then, concurrently, do the seek,
then read data from the platter into its buffer, and reconnect
only when it is ready to copy data into host RAM.


Yes, but that is NOT simultaneous data transfer.

This capability is one reason why it makes sense to use
a 320 MB/s (U320) version of SCSI to attach HDs which
have STRs of less than a quarter of the bus data rate.


Separate issue entirely.

Moreover, with command queuing, a bunch of read commands can
be issued to each HD, and each HD can execute them out-of-order
and briefly re-occupy the SCSI bus to do the actual data transfer.


Separate issue entirely. And command queuing
isnt just available with SCSI anyway.

And yes, it works the same way for writes
and for mixtures of reads and writes.


Sure, but you never get simultaneous data transfer from
multiple drives, they still have to do that sequentially.

IDE is actually better with the usual 2 controllers in that respect.

I am not claiming that WinWhatever takes full advantage of the
capabilities of SCSI, but there are grown-up OSs which do.


No OS can achieve simultaneous data transfer
with multiple SCSI drives on a single bus.



  #13  
Old July 28th 03, 07:48 PM
Rod Speed
external usenet poster
 
Posts: n/a
Default


Jonathan Sachs wrote in message
...
Rod Speed wrote


The short story is that its only simultaneous ops on a
pair of drives that benefits from having that pair on a
separate channel. Thats pretty uncommon in practice...


I think your entire argument assumes that the
computer is being used to do one thing at a time


Nope. What matters is how often there is significant
drive activity on more than one drive at a time.

And SCSI cant transfer data simultaneously from more
than one drive at a time anyway, ALL it can do is allow
one drive to seek while another is transfering data etc.

-- something which, for me, is emphatically not true.
It's common for me to have a dozen windows open at once,
and two or three applications actively working simultaneously.


Yes, but what matters is how intensively each of those apps
is using the drive(s) its using. With say burning a CD from the
hard drive, the app normally does that sequentially. And what
matters is whether the app can get frequent enough access
to the hard drive to get enough data to keep the burner happy
when that output rate is MUCH lower than the hard drive.

What if I'm writing a document while referring
to information on a DVD ROM or CD ROM?


The app thats used to write the document is hardly ever
using the hard drive, just when you save the document
occassionally. So that app isnt using the hard drive and the
ROM drive literally simultaneously in a data transfer sense.

Since I have carpal tunnel syndrome, I depend
on speech recognition software to write, and it is
quite disk intensive (as well as CPU intensive).


Sounds like its rather badly design or
you dont have enough physical ram.

In that situation, sharing an IDE channel between
the DVD/CD drive and one of my hard disks could
be like trying to eat dinner with one hand.


Nope, nothing like it in fact. And you just have the hard
drive on a different channel to the DVD/CD drive anyway,
no need for a separate channel for every one of the drives.

And SCSI cant do simultaneous data transfers
anyway, in some ways its even worse with just
one bus instead 2 with standard IDE.

The only real advantage SCSI has is that a slow seeking
drive can disconnect from the bus while its seeking etc.
IDE achieves an even better result with 2 channels
because there isnt even any need to disconnect.



  #14  
Old July 29th 03, 04:05 AM
Lifelong US Citizen
external usenet poster
 
Posts: n/a
Default

On Mon, 28 Jul 2003 08:41:39 GMT, "Tod"
wrote:


"Jonathan Sachs" wrote in message
.. .
"Tod" wrote:

A "Quality" high end SCSI hard drive will last longer
under long term disk-intenive (24 hour a day) work.
But you are paying a lot more money.



Buy some "used" SCSI drives on EBay. Lots of good values for U160
drives, since people seem to be upgrading their servers to U320.

Also, another point for using at least some SCS in your system is that
good tape backup units are all SCSI-based.

I should also add that I have never had a SCSI drive fail, except one
Quantum drive way, way back when.

And modern SCSI drives are very quite also.
  #15  
Old July 29th 03, 08:12 AM
Jonathan Sachs
external usenet poster
 
Posts: n/a
Default

Lifelong US Citizen wrote:

And modern SCSI drives are very quite also.


Can you provide specifics?

I'm currently using two 36 GB Ultra160 drives from Seagate. One is
about a year old, the other, probably three years old. I believe their
idle noise level was rated around 3.4 bels, and I don't know of any.
standard SCSI drives which are much quieter than that. I find the
noise very bothersome.

My mail address is jsachs177 at earthlink dot net.
  #16  
Old July 29th 03, 08:18 AM
Simon
external usenet poster
 
Posts: n/a
Default

A quick analogy for you:

IDE 4 cylinder. SCSI V8.

They both do the same job, but you know that the SCSI will go on for ever,
and not wear itself out.

Simon

Oh yes, we still sell hundreds of SCSI drives per month.

"Gareth Church" wrote in message
...
"Folkert Rienstra" wrote in message
...
Although SCSI has always been considered superior, IDE performance
has improved drastically in recent years,

So has SCSI's.

No where near to the same extent.


Ofcourse it has.


Nope. I'm not suggesting IDE has surpassed SCSI, or SCSI hasn't been able

to
keep up. But SCSI has traditionally been a lot faster and more reliable

than
IDE, so there was less room for improvement.

From a performance point of view, now that
you can use IDE RAID, SCSI doesn't offer much more.


SCSI RAID, obviously.


Why would SCSI RAID offer a performance improvement over IDE? SCSI drives
may still be a bit faster in read/writes, but they are a lot more

expensive.
If you were planning on having a SCSI RAID 0 array with 2 drives, why not
get a bit more performance, more storage space, and save a few dollars by
using 3 IDE disks?

That's for throughput. There are other speed advantages that SCSI holds of
course (seek time, task queueing etc). These are important in some areas,
but for most machines the difference won't be noticable.

From a reliability point of view SCSI is obviously still ahead,


Nope. There is where ATA indeed made good.


Indeed. But I don't think it has caught up to SCSI (whereas I think it has
in performace, now we have IDE RAID). As far as IDE has come, I wouldn't
trust it in an important server.

but IDE has come a long way. Given the substantial price dif-
ference, you have to consider whether SCSI is really worth it.


Ofcourse, but that goes for every component on the system.


Yes, but we are comparing SCSI and IDE here. That's what the subject of

the
thread is. Saying all components have improved over time is kinda obvious,
what we are discussing here is their improvements comparative to one
another.

For a home system like the OP is talking about, though,
SCSIs negatives (namely price) far outweigh it's benefits.


Same can be said for processors, perhaps even more so.
However, processors are much sexier, for some stupid reason or other.


Yeah, for some reason people who really don't need to pay to get a top of
the line CPU, when they could have paid half as much and got something 80%
as fast for half the money. And why? For bragging rights for a couple of
weeks. But when talking about hard drive sexiness, SATA is where it's at.
There aren't really any compelling reasons at all to use SCSI in a desktop
machine any more.

I don't think he meant standard in any official sense


IDE always was standard on a PC, it's not 'becoming' standard.


Yes, hence my previous statement.

SCSI always has been for Servers and highend Workstations.


Yes, but IDE is starting to take market share in these areas. Obviously

not
for vital servers, but for workstations and some non-critical servers IDE

is
becomming a more and more attractive option. This is a trend that will
continue. It's a cycle; fewer people use it, so less gets invested, so it
falls further behind, so even fewer people use it.

(ie. that it is planned to phase out SCSI and replace it with IDE),
but SCSIs market is certainly shrinking.


It isn't. Maybe it will with SATA and SAS on the horizon.
However for SATA to become external you need SAS.


I don't see how you can say it isn't. I know of quite a few businesses

that
are now using IDE drives in their servers, and have heard of many more doi

ng
the same. And more and more threads like this one are popping up, where
peope who have used SCSI are wondering if it is still worth it. You can

deny
it all you like, but it is happening.

I would strongly consider using IDE drives for some servers these

days,

That's entry level server.


That's correct.

and I'm not alone.


IDE is fine for central backup. It isn't for multiuser/multitasking.


Agreed.

IDE is a goner. SATA *may* take inroads in the higher end workstation
business and parts of the server business by introducing professional
grade SATA drives like the current WD RAPTOR.


There's no may about it. It will happen (well, it already is).

SCSIs niche will continue to be infiltrated by IDE, meaning that
prices for SCSI will rise and support and innovation will decrease.


IDE is nearly dead, SCSI will soon be. SAS and SATA will take over.


SATA is still IDE (which is more correctly known as ATA - which as you may
have noticed makes up 3 of the 4 letters of SATA). It just uses a

different
interface. At the moment it provides virtually no improvement over

parallel
ATA.

Other than what I've just read, I don't know anything about SAS so can't
comment.


When SATA starts to invade the server business too much, SAS will
have to come down in price.


That's my point. SCSI is slowly losing ground. The more this happens, the
less likely companies are going to want to invest money into developments
for it. Add to that that they will have to make the drives cheaper in

order
to remain competitive, and they will really start to wonder why they are
spending money trying to compete for what is a small market, when the

number
of units is low (so manufacturing costs are high), and profits are

becoming
lower. If I were a hard drive manufacturer now, I would seriously consider
concentrating on IDE, and leaving other manufacturers to fight for the

small
SCSI (and SAS) market share.

However, if SAS can sustain market share
by taking over some Fiber Channel business, that may not happen.


I don't know how important that is. Even if it does you are still talking
about a relatively small market. Whatever happens in that market, IDE will
still be the dominant force for the majority of the worlds machines.

Gareth




  #17  
Old July 29th 03, 08:19 AM
Simon
external usenet poster
 
Posts: n/a
Default

50Gb $45US - Lousy value? Its where you shop


"Rod Speed" wrote in message
...

Jonathan Sachs wrote in
message ...

I'm assembling a new system in a couple of months,
and am facing the old dilemma: SCSI or IDE disks?


SCSI has basically passed its useby date for all except the most
demanding situations. Basically lousy value for money now.

I have traditionally insisted on SCSI disks because they're faster and
more reliable. Lately I've been having some hearing problems, though,
and the drive noise is bothering me. Thus I'm motivated to use IDE
drives in my next system if I can do so without too much compromise.


What about performance? If I run two or or three disk-intensive
applications under Windows, will there be much practical difference
between a pair of fast Ultra320 drives and a pair of fast IDE drives?


I doubt you'd be able to pick the difference in a
proper double blind trial with your ears plugged.

I will have at least three IDE devices: two hard disks
and a CD/RW or DVD drive. I'm assuming that each
device should go on a dedicated channel.


No need.

If so, should I get a mainboard with four IDE channels
built in, or will an add-on adapter work equally well?


2 channels will be fine.

What about reliability? Are modern IDE drives reliable
enough for all practical purposes? (I define this to mean
a negligible chance of failure over a system life of three
years, with the drives running almost constantly.)


Yep.

Are there any popular brands or models which
have particularly good or bad reputations?


I like the WDs myself. I avoid the Hitachi/IBMs because
of the atrocious record they got with relatively recent
drives and the fact that they have a lousy RMA system.

Best to avoid the Seagate Barracudas in your situation
because they have chosen to disable AAM because of
some stupid claim about patent infringement. That means
that the currently buyable drives arent that quiet anymore.




  #18  
Old July 29th 03, 09:29 AM
Rod Speed
external usenet poster
 
Posts: n/a
Default


Simon wrote in message
...

50Gb $45US - Lousy value?


Pity about the price of IDE, salesfool.

Its where you shop


Usual salesfool liar.

You obviously flogged used cars previously.


"Rod Speed" wrote in message
...

Jonathan Sachs wrote in
message ...

I'm assembling a new system in a couple of months,
and am facing the old dilemma: SCSI or IDE disks?


SCSI has basically passed its useby date for all except the most
demanding situations. Basically lousy value for money now.

I have traditionally insisted on SCSI disks because they're faster and
more reliable. Lately I've been having some hearing problems, though,
and the drive noise is bothering me. Thus I'm motivated to use IDE
drives in my next system if I can do so without too much compromise.


What about performance? If I run two or or three disk-intensive
applications under Windows, will there be much practical difference
between a pair of fast Ultra320 drives and a pair of fast IDE drives?


I doubt you'd be able to pick the difference in a
proper double blind trial with your ears plugged.

I will have at least three IDE devices: two hard disks
and a CD/RW or DVD drive. I'm assuming that each
device should go on a dedicated channel.


No need.

If so, should I get a mainboard with four IDE channels
built in, or will an add-on adapter work equally well?


2 channels will be fine.

What about reliability? Are modern IDE drives reliable
enough for all practical purposes? (I define this to mean
a negligible chance of failure over a system life of three
years, with the drives running almost constantly.)


Yep.

Are there any popular brands or models which
have particularly good or bad reputations?


I like the WDs myself. I avoid the Hitachi/IBMs because
of the atrocious record they got with relatively recent
drives and the fact that they have a lousy RMA system.

Best to avoid the Seagate Barracudas in your situation
because they have chosen to disable AAM because of
some stupid claim about patent infringement. That means
that the currently buyable drives arent that quiet anymore.






  #19  
Old July 29th 03, 01:31 PM
Gareth Church
external usenet poster
 
Posts: n/a
Default

"Simon" wrote in message
...
A quick analogy for you:

IDE 4 cylinder. SCSI V8.


A quick analogy, and a worthless one (like most are). I've heard the same
analogy used in the Mac vs PC debate. It's says nothing. It's the sort of
thing people say when they have a strong opinion, but can't come up with any
actual reason why they feel the way they do.

They both do the same job, but you know that the SCSI will go on for ever,
and not wear itself out.


Your hyperbole aside, I do agree that on the whole SCSI is more reliable
than IDE.

Really, if that is your opinion why didn't you just say it? The analogy was
dumb, and isn't analogous at all. The difference between a 4 cylinder engine
and a V8 isn't how long they last, it's power. If you want to find something
analogous to that in the hard drive world (which is a pointless thing to
do), it would be sustained transfer rate, not reliability.

Gareth


  #20  
Old July 29th 03, 04:24 PM
Joshua P. Hill
external usenet poster
 
Posts: n/a
Default

On Tue, 29 Jul 2003 18:24:21 +1000, "Rod Speed"
wrote:


Simon wrote in message
...

A quick analogy for you:


IDE 4 cylinder. SCSI V8.


Mindlessly superficial.


Takes one to know one, I guess.

They both do the same job, but you know that the
SCSI will go on for ever, and not wear itself out.


Mindlessly superficial.


Yeah, Roddy, we're really convinced when you start to repeat yourself.
Reminds us of our eight-year-olds in a snit.



Josh
 




Thread Tools
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
15K rpm SCSI-disk Ronny Mandal General 26 December 8th 04 09:04 PM
Newbie Question re hardware vs software RAID Gilgamesh General 44 November 22nd 04 11:52 PM
my new mobo o/c's great rockerrock Overclocking AMD Processors 9 June 30th 04 08:17 PM
Advice Please: Building Simple "Back-up" System Darren Harris General 0 December 18th 03 03:10 AM
Questions about memory and a few other things for the AMD/Asus system I am building (long) Jim Homebuilt PC's 3 September 16th 03 09:05 AM


All times are GMT +1. The time now is 07:06 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 HardwareBanter.
The comments are property of their posters.