To RAID or not to RAID?

Yes it sounds like a newbie question, anyway...

Which is beter for performance, a single hard drive of say, 160 GB or
two 80 gig drives in a RAID 0 config? Going to get a SATA II hard
drive (want to test the nF4 hack) and I see a 160 gig drive is about
$20 cheaper than two 80G drives. Assuming a 7200rpm disc speed and the
same manufacturer, is a striped config of two drives faster than a
single drive equal in size to the other two? Wouldn't the single drive
naturally be faster? Just thought I'd ask, and thanks.

ah,,,

No


wrote in message
oups.com...
Yes it sounds like a newbie question, anyway...

Which is beter for performance, a single hard drive of say, 160 GB or
two 80 gig drives in a RAID 0 config? Going to get a SATA II hard
drive (want to test the nF4 hack) and I see a 160 gig drive is about
$20 cheaper than two 80G drives. Assuming a 7200rpm disc speed and the
same manufacturer, is a striped config of two drives faster than a
single drive equal in size to the other two? Wouldn't the single drive
naturally be faster? Just thought I'd ask, and thanks.

wrote in message
oups.com...
Yes it sounds like a newbie question, anyway...

Which is beter for performance, a single hard drive of say, 160 GB or
two 80 gig drives in a RAID 0 config? Going to get a SATA II hard
drive (want to test the nF4 hack) and I see a 160 gig drive is about
$20 cheaper than two 80G drives. Assuming a 7200rpm disc speed and the
same manufacturer, is a striped config of two drives faster than a
single drive equal in size to the other two? Wouldn't the single drive
naturally be faster? Just thought I'd ask, and thanks.


Read a review on the 1st SATA 2 drive from Hitachi. It is a fast drive but
absolutely no noticeable performance increase over SATA 1. As a matter of
fact, hard drives can't even meet sata 1 potential.

wrote:

Yes it sounds like a newbie question, anyway...

Which is beter for performance, a single hard drive of say, 160 GB or
two 80 gig drives in a RAID 0 config? Going to get a SATA II hard
drive (want to test the nF4 hack) and I see a 160 gig drive is about
$20 cheaper than two 80G drives. Assuming a 7200rpm disc speed and the
same manufacturer, is a striped config of two drives faster than a
single drive equal in size to the other two? Wouldn't the single drive
naturally be faster? Just thought I'd ask, and thanks.

If RAID 0 isn't faster what is the point of it? Why would anybody do it?

Never done RAID, so here's a newbie answer to the newbie question.
From what I read, there's not that much to be noticed in RW terms from RAID.
But it does introduce a substantial reliability issue.
Not just because you have twice the hardware to malfunction, but because
many boards have RAID implementation issues.
If your data's valuable to you, stick to unRAIDed IDE, 'cos the only time
RAID makes any perceptible difference is when loading programs/Windows.
An atrocious trade-off IMNSHO.

wrote:
Yes it sounds like a newbie question, anyway...

Which is beter for performance, a single hard drive of say, 160 GB or
two 80 gig drives in a RAID 0 config? Going to get a SATA II hard
drive (want to test the nF4 hack) and I see a 160 gig drive is about
$20 cheaper than two 80G drives. Assuming a 7200rpm disc speed and
the same manufacturer, is a striped config of two drives faster than a
single drive equal in size to the other two? Wouldn't the single
drive naturally be faster? Just thought I'd ask, and thanks.

I ask a question, so why is it so difficult for anyone to understand:
how should I know whether two RAID'ed drives are faster than a single
larger drive UNLESS I ASK? RAID was built for not only speed but
mirroring abilities as well. I can see two striped drives being faster
than a single drive OF A DIFFERENT SIZE AND MANUFACTURER but how would
I know unless I've used a raid system in the past, and I haven't.

The point of my question was not whether SATA II has any noticeable
increase in transfer speeds over SATA I (which I already know it
doesn't, that is, for the time being) or why RAID was developed in the
first place. And one word answers, although nice and to the point, are
just as vague as saying nothing at all.

From my POV it's like this: I ask a question hoping somebody out there
will answer who actually has had experience with RAID configurations
and knows whether 2 drives really are faster than one drive of equal
size or not. I get the jist of these answers (that in fact they are)
but no indication at all that anyone actually KNOWS. I appreciate your
replies but they only indicate opinion and conjecture, not knowledge,
and really don't answer anything for me.

Maybe I ask and expect too much, after all it is only Usenet, but what
the hey, it's a free country right. Happy Mem Day to one and all!

On Fri, 27 May 2005 14:37:19 -0700, theredpriest wrote:

I ask a question, so why is it so difficult for anyone to understand:
how should I know whether two RAID'ed drives are faster than a single
larger drive UNLESS I ASK? RAID was built for not only speed but
mirroring abilities as well. I can see two striped drives being faster
than a single drive OF A DIFFERENT SIZE AND MANUFACTURER but how would
I know unless I've used a raid system in the past, and I haven't.

Raid 0 is faster than no raid. If you really want to know about raid you
need to do some reading. there's many different raid levels which do
different things. Personally, I'd never use raid 0 alone without a good
backup procedure. Now 0+1 would be nice, but requires 4 drives. Here's a
starting point.

http://www.webopedia.com/TERM/R/RAID.html

--
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My server http://wesnewell.no-ip.com/cpu.php
Verizon server http://mysite.verizon.net/res0exft/cpu.htm

raid is definatly faster
better sustained transfers, ive only used a 2 drive array, i would never go
back to using a single drive again
2x120gig sata hitachi 7200rpm 8mb cache
as for RW performance windows/games feel much more quicker for me

ask anyone what there ideal hard drives would be and i bet they say 2x
raptors in raid
wrote in message
oups.com...
Yes it sounds like a newbie question, anyway...

Which is beter for performance, a single hard drive of say, 160 GB or
two 80 gig drives in a RAID 0 config? Going to get a SATA II hard
drive (want to test the nF4 hack) and I see a 160 gig drive is about
$20 cheaper than two 80G drives. Assuming a 7200rpm disc speed and the
same manufacturer, is a striped config of two drives faster than a
single drive equal in size to the other two? Wouldn't the single drive
naturally be faster? Just thought I'd ask, and thanks.

You'll like this.

http://www.pacificdigital.com/produc...CPlusAward.pdf


--
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Send spam to the FTC at

Thanks, robots.

wrote:
Yes it sounds like a newbie question, anyway...

Which is beter for performance, a single hard drive of say, 160 GB or
two 80 gig drives in a RAID 0 config?

Depends on the drives. If you're comparing an identical model drive, say two
80GB 7200.7's vs a 160GB 7200.7 then the two 80's will be faster in most if
not all tests. I give myself wiggle-room as RAID0 has on average very
slightly higher seek times than a single non-RAID0. Very slightly being in
around 0.1ms or so in the worst real-world case, though you can devise
pathelogical access patterns that will make a RAID0 setup choke. In most
real-world situations, you don't need to worry.

This is because the 80GB drive might have two 40GB platters, and the 160GB
drive would just have twice this, so 4 platters. This is not always the case
(such as the 120GB WD1200JB's having larger platters than an 80GB WD800JB at
the same point in time) but it generally holds. However, if you are
comparing (say) two 80GB 7200.7's vs a 160GB 7200.8 (if it existed) then you
have a couple of differences. The 7's have 80GB per platter, but the 8's
have 100GB per platter. Also the actuator or firmware could have been
improved in the 8, improving seek times or TCQ performance. Unfortunately,
in this case the 8 is oftes SLOWER than the 7, but there is certainly a
possibility that a newer model drive can beat two older drives in RAID0 in a
number of situations (particularily those that are seek-time limited).

[...]

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