Archived from groups: microsoft.public.windowsxp.hardware (More info?)

Howdy all,

I'm setting up a RAID 0 array in a new computer I'm
building.

I've narrowed it down to 2 Western Digital Raptors, on
the thinking that since RAID 0 with 2 drives, you have
double the chance to lose all your data, but Western
Digital drives are at LEAST 2x better and more reliable
than any drive out there. Hoping the positive will
balance out the negative.

The question is this, Will the 74 gig Raptor outperform
the 36 gig Raptor? Western Digital has it on their site
that the 74 gig SATA Raptor is outperforming SCSI 10k and
15k drives. Is this the same for a 36 gig drive?

My only other concern is disk space. I definately won't
use all of a 148 gig array, but I may be lacking space
with a 72 gig array. I'm an avid gamer and later this
year will be getting into picture and video editing with
the coming of a new digital camera.

Any feedback is appreciated.

Archived from groups: microsoft.public.windowsxp.hardware (More info?)

Forgot to mention that 10k RPM about the Raptors...That's
amazing. Cuts the average seek time of most drives in
half!

That's the kind of performance I'm looking for.


>-----Original Message-----
>Howdy all,
>
>I'm setting up a RAID 0 array in a new computer I'm
>building.
>
>I've narrowed it down to 2 Western Digital Raptors, on
>the thinking that since RAID 0 with 2 drives, you have
>double the chance to lose all your data, but Western
>Digital drives are at LEAST 2x better and more reliable
>than any drive out there. Hoping the positive will
>balance out the negative.
>
>The question is this, Will the 74 gig Raptor outperform
>the 36 gig Raptor? Western Digital has it on their site
>that the 74 gig SATA Raptor is outperforming SCSI 10k
and
>15k drives. Is this the same for a 36 gig drive?
>
>My only other concern is disk space. I definately won't
>use all of a 148 gig array, but I may be lacking space
>with a 72 gig array. I'm an avid gamer and later this
>year will be getting into picture and video editing with
>the coming of a new digital camera.
>
>Any feedback is appreciated.
>.
>

Archived from groups: microsoft.public.windowsxp.hardware (More info?)

"John Kimble" <anonymous@discussions.microsoft.com> wrote in message
news:1e54e01c454ee$131e29b0$a001280a@phx.gbl...
> Forgot to mention that 10k RPM about the Raptors...That's
> amazing. Cuts the average seek time of most drives in
> half!
>
> That's the kind of performance I'm looking for.

I wouldn't pay that much for a drive, of which the only performance gain is
the seek time speed. You may be thinking that you are almost cutting that
speed in half, which is true. But when you figure the seek time between a
160gig 7400RPM SATA drive @ avg Seek time 8.5ms to 4.5ms for a 10,000RPM
SATA 74gig (less than half the drive space) for an avg of $70 more, is not
worth it. This due to the fact that most people won't be able to discern 8
milliseconds from 4 milliseconds (thousandths of a second) in seek time
speed, and that one's processor can only process as fast as it can go.

Also, if your going to have two HDDs, I wouldn't recommend a RAID0 array, as
you stated, if it fails, it all fails. Why not a RAID1, then you can fall
back on the same setup, and backup constantly. But IMHO, I would simply set
it up as two separate (basic) drives, and load all of my games and files to
the secondary drive. You figure 74gigs would hold (easily) an avg. of 35
games. You would get bored or outplay the usefulness of most of them before
you would feel the need to keep them stored. You can just as easily play
them from there, as the transfer rates work the same regardless of the
setup.

Archived from groups: microsoft.public.windowsxp.hardware (More info?)

No, there isn't much of a difference in 8.5 ms compared
to 4.5. If it were only one seek I would agree with you.
But there are LOTS of seeks. Those ms's add up.

Plus, I'm not only paying for the extra speed, but also a
5 year warranty and one damn solid drive. My experiences
with Western Digital have been outstanding to this point,
and I have no reason to believe they won't continue to be.


>-----Original Message-----
>
>"John Kimble" <anonymous@discussions.microsoft.com>
wrote in message
>news:1e54e01c454ee$131e29b0$a001280a@phx.gbl...
>> Forgot to mention that 10k RPM about the
Raptors...That's
>> amazing. Cuts the average seek time of most drives in
>> half!
>>
>> That's the kind of performance I'm looking for.
>
>I wouldn't pay that much for a drive, of which the only
performance gain is
>the seek time speed. You may be thinking that you are
almost cutting that
>speed in half, which is true. But when you figure the
seek time between a
>160gig 7400RPM SATA drive @ avg Seek time 8.5ms to 4.5ms
for a 10,000RPM
>SATA 74gig (less than half the drive space) for an avg
of $70 more, is not
>worth it. This due to the fact that most people won't be
able to discern 8
>milliseconds from 4 milliseconds (thousandths of a
second) in seek time
>speed, and that one's processor can only process as fast
as it can go.
>
>Also, if your going to have two HDDs, I wouldn't
recommend a RAID0 array, as
>you stated, if it fails, it all fails. Why not a RAID1,
then you can fall
>back on the same setup, and backup constantly. But IMHO,
I would simply set
>it up as two separate (basic) drives, and load all of my
games and files to
>the secondary drive. You figure 74gigs would hold
(easily) an avg. of 35
>games. You would get bored or outplay the usefulness of
most of them before
>you would feel the need to keep them stored. You can
just as easily play
>them from there, as the transfer rates work the same
regardless of the
>setup.
>
>
>.
>

Archived from groups: microsoft.public.windowsxp.hardware (More info?)

You can put a fan that "blows on the harddisks". That should double the
lifetime :-).

I've been using 2x IBM 180 GXP and 2x 300 gb SATA disks (don't remember the
manufacter) with RAID0 in over half a year now (one year for the IBM disks),
and they haven't failed yet. ;-)

// Chen

<anonymous@discussions.microsoft.com> skrev i meddelandet
news:1e3b301c45524$0c53ab10$a501280a@phx.gbl...
> No, there isn't much of a difference in 8.5 ms compared
> to 4.5. If it were only one seek I would agree with you.
> But there are LOTS of seeks. Those ms's add up.
>
> Plus, I'm not only paying for the extra speed, but also a
> 5 year warranty and one damn solid drive. My experiences
> with Western Digital have been outstanding to this point,
> and I have no reason to believe they won't continue to be.
>
>
> >-----Original Message-----
> >
> >"John Kimble" <anonymous@discussions.microsoft.com>
> wrote in message
> >news:1e54e01c454ee$131e29b0$a001280a@phx.gbl...
> >> Forgot to mention that 10k RPM about the
> Raptors...That's
> >> amazing. Cuts the average seek time of most drives in
> >> half!
> >>
> >> That's the kind of performance I'm looking for.
> >
> >I wouldn't pay that much for a drive, of which the only
> performance gain is
> >the seek time speed. You may be thinking that you are
> almost cutting that
> >speed in half, which is true. But when you figure the
> seek time between a
> >160gig 7400RPM SATA drive @ avg Seek time 8.5ms to 4.5ms
> for a 10,000RPM
> >SATA 74gig (less than half the drive space) for an avg
> of $70 more, is not
> >worth it. This due to the fact that most people won't be
> able to discern 8
> >milliseconds from 4 milliseconds (thousandths of a
> second) in seek time
> >speed, and that one's processor can only process as fast
> as it can go.
> >
> >Also, if your going to have two HDDs, I wouldn't
> recommend a RAID0 array, as
> >you stated, if it fails, it all fails. Why not a RAID1,
> then you can fall
> >back on the same setup, and backup constantly. But IMHO,
> I would simply set
> >it up as two separate (basic) drives, and load all of my
> games and files to
> >the secondary drive. You figure 74gigs would hold
> (easily) an avg. of 35
> >games. You would get bored or outplay the usefulness of
> most of them before
> >you would feel the need to keep them stored. You can
> just as easily play
> >them from there, as the transfer rates work the same
> regardless of the
> >setup.
> >
> >
> >.
> >

Archived from groups: microsoft.public.windowsxp.hardware (More info?)

"John Kimble" <anonymous@discussions.microsoft.com> wrote...
>
> The question is this, Will the 74 gig Raptor outperform
> the 36 gig Raptor? Western Digital has it on their site
> that the 74 gig SATA Raptor is outperforming SCSI 10k and
> 15k drives. Is this the same for a 36 gig drive?

The Raptor 74 is not just a 36 with 2 platters -- it was rebuilt as a new
HD. All reviews I've read say the 74 significantly outperforms the 36.

BTW, I like my Raptor 74s in RAID 0!

Archived from groups: microsoft.public.windowsxp.hardware (More info?)

"Nicholas T. Pappas" <ntpappas@yahoo.com> wrote...
>
> Before I start, I will tell you that I am a systems
> engineer specializing in performance (load and stress)
> testing of commercial grade servers. In other words, I
> evaluate computer speeds for a living, and I have been
> doing this for over 20 years.

Good credentials, but credentials aren't the whole picture when dealing with
analyses...


> Before I comment on using RAID, I want to remind you that
> drives also have a data bandwidth rating - the maximum
> amount of data they can read/write per second. The value
> would most likely be the limiting factor in my first
> example - copying a large, file from one completely
> defragmented physical drive to another completely
> defragmented physical drive. For SATA it is 150 MBS vs.
> 133 MBS for the fastest parallel ATA. Here, seek time has
> nothing to do with it, and the limiting factor would most
> likely be this value, so the WD 74 gig Raptor would not
> even have any significant improvement a sluggish 133 ATA
> 5600 RPM "home computer" drive such as a Maxtor 250.

The "data bandwidth rating" you note above is NOT a function of the drive,
but of the bus/controller on which it is hosted. Also, that is a maximum
burst rate, NOT a sustained rate. Note that WD terms it the max "buffer to
host" data transfer rate, so it will only approach that rate when the disk
buffer contains the requested data.

That Maxtor (5400, not 5600, BTW) you cite has a max data transfer rate per
drive of 46 MBps. If you read an older Cheetah data sheet, you will find
the max internal ("buffer to disk" ) transfer rate is 682 Mbps or 63.2 MBps
(gen 6, SCSI 160, 10K RPM version); the latest gen 4, 15K RPM (contemporary
of gen 7, 10K) is 96 MBPS. By comparison, the Raptor 74 weighs in at 102
MBps. [Note: All are mfgr's specs, but should be good for comparison
purposes.]

So, while the external bus may have a max bandwidth as you note, the drive
itself has internal limitations that may be significantly more restrictive
than the external bus. Note that the Barracuda 5400 could not approach the
max theoretical ATA 100/133 bus bandwidth -- even a pair of them with RAID 0
striping -- but a pair of Raptor 74s or Cheetah 15Ks could do so in theory.

Also, if the ATA controller is on the 32-bit PCI bus (via controller card),
it will share the 133 MBps max bandwidth of the PCI bus with everything else
on the bus.


> To
> obtain a speed increase when data rate is the limiting
> factor, I would have to graduate to the latest SCSI which
> is 320 MBS. (And, by the way, the uncontested fastest
> drive in the world for several years remains the Seagate
> Cheetah with a seek time around 3.7 ms and a data transfer
> rate of 320 MBS.)

As I note above, 320 MBps is the SCSI bus max data transfer rate, and the
Cheetah itself tops out at 96 MBps. You can only begin to approach 320 MBps
data transfer rate in a 3- or 4-drive array, and then only if all other
components support it.


> It is also true that your
> chances of losing data due to drive failure is doubled.
> (It is the same story with small aircraft: a two engine
> prop plane is twice as likely to crash since there are two
> engines to fail, and it is too difficult for all but the
> best pilots to fly on only one engine with the other one
> dragging its prop through the air.)

BAD analogy, and indicative of your lack of true analysis!

Your "too difficult..." statement has a modicum of truth, but ONLY in
limited circumstances -- when the engine fails just after takeoff, when the
airplane's speed is low, the drag is high, and margin for error is minimal.
Your generalization also does not take into consideration airplane
configuration (what if the engines are mounted fore and aft, like the
C336?), jet-powered airplanes, and installed technologies such as
auto-feather systems.

Also, an engine failure in either a single- or twin-engine airplane does NOT
imply or guarantee an impending "crash." MANY airplanes of both types land
successfully with failed engines!


Finally, MTBF rates among various HD brands and types can vary by a factor
of 10 or 100 or more. Even if the risk of data loss is "doubled" by using
RAID 0, you can more than compensate by choice of a more reliable drive in
the beginning.