 Re: Noise level of two hdd in raid 0...
On Tue, 17 Oct 2006 15:38:17 -0400, "KILOWATT"
<kilowatt"nospam"@softhome.net> wrote:
>Hi. thanks to read.
>
>I know that there's a lot of discussions about the real increase in
>performances when going with two raid 0'ed drives. None seems to agree and
>everyone is right! :-)
This is because of factors like:
- The use, applications
- Size of files
- Drive performance vs controller bandwidth
- Bandwidth dedicated to the controller vs shared with
other devices as related to the next point.
- Differences in realized throughput when comparing isolated
benchmarks which are mostly (if not entirely) letting the
controller have as much bandwidth as possible, versus real
world uses where the system "might" have other devices in
contention for that bandwidth. The determination of this
depends on understanding the logical connections of your
motherboard chipset, and again the uses of the system where
the performance gain is expected, measured, or needed
(most).
>But the noise issue is not freequently discussed.
.... because they're only a little louder, the peak noise
should be no worse than two drives not in an array, but more
continuous since both are continually being accessed, and
neither will be going to sleep while in a many uses with two
separate volumes, power management will spin down the second
drive.
> My
>next PC will be used mainly as an htpc... so noise is a factor to consider.
Not to nitpick or anything, but why not mention this up
front instead of having all these factors considered? My
point being, you should not need RAID0 at all on a HTPC,
unless for some reason you are only using uncompressed, not
DV, to capture and play. In that case you'll need far more
than two drives anyway as uncompressed video is such high
bitrate.
>For the whinning noise when the platters are spinning, i'm almost shure that
>it won't be an issue, especially these days with dynamic fluid bearings. But
>what about the seek noise? Twice as much...or there's not really a
>difference with two drives?? TIA for your replies...
There can be significant difference, but large semi-linear
files (unless fragmented) as in audio/video don't have
significant seek issues, you dont' need drives in
non-accoustic-managed modes, can set them to quietest mode.
However, unless you are sitting quite close to the system,
you should not be able to hear seek noise unless you have a
very poor case, and thus a better solution for lowest noise
tends to be to change, or soundproof the existing case, as
it will also tend to keep any fan noise and vibrational
noise minimized too.
To more directly answer, what little seek noise there would
be, yes there will be roughly twice as much (though not
additive in volume) during the moments of drive access, but
IF you really realized any gain from the RAID array in
performance, it would take less time to access and thus,
shorter duration of the seek noise.
In summary, there is no need for RAID0 on a HTPC, even if it
were quiet.
 | 
Linear Mode
