SATA/RAID Slowdown?

I have a machine that has SATA/RAID capability that I have never used.
Now I am considering it - but since I am at best a novice on this, I
have to ask.

Will the presence and activation of SATA/RAID slow my machine down
overall? It is a AMD 3200+ Athlon64. I notice slow-downs already
whenever I multi-process applications.

Thanks

Jethro

On Tue, 02 Jan 2007 09:30:58 -0600, Joel <Joel@NoSpam.com> wrote:

>Jethro <Wilson@somewhere.org> wrote:
>
>> I have a machine that has SATA/RAID capability that I have never used.
>> Now I am considering it - but since I am at best a novice on this, I
>> have to ask.
>>
>> Will the presence and activation of SATA/RAID slow my machine down
>> overall? It is a AMD 3200+ Athlon64. I notice slow-downs already
>> whenever I multi-process applications.
>>
>> Thanks
>>
>> Jethro
>
> My mboard supports both SATA/RAID too, and I haven't tried neither one yet
>(I have 500GB SATA but still using as external via USB2). But I don't see
>why a faster hard drive can slow down the system.

I was picturing the overheads of continuous RAID backups. The two
drives would both go thru the MOBO components. To me, intuitively, I
just figgered that double write would take more time than single
write. Could I be wrong?


>
> I have AMD 3700+ with 3GB memory. I use it for photo post processing
>(Photoshop) and multimedia (either converting or authoring), and often have
>several other aps running at same time. And I use "Task Manager" to control
>the speed of system by knowing which prg requires or need more CPU and how
>each uses the CPU to control them.

Hmmm
I've never tried to use Task Manager to that end. Don't know how
either. Maybe I should look at that.

Thanks

Jethro

It's not a double write. If you are doing simple raid-1 aka mirroring, the
write command is sent to the raid controller which then sends individual
writes commands to each drive. So the system only goes as slow as your
slowest drive.


---Matthew Hicks


"Jethro" <Wilson@somewhere.org> wrote in message
news:bn2lp29617i2mi27d21ucnosqo31hsjhqn@4ax.com...
> On Tue, 02 Jan 2007 09:30:58 -0600, Joel <Joel@NoSpam.com> wrote:
>
>>Jethro <Wilson@somewhere.org> wrote:
>>
>>> I have a machine that has SATA/RAID capability that I have never used.
>>> Now I am considering it - but since I am at best a novice on this, I
>>> have to ask.
>>>
>>> Will the presence and activation of SATA/RAID slow my machine down
>>> overall? It is a AMD 3200+ Athlon64. I notice slow-downs already
>>> whenever I multi-process applications.
>>>
>>> Thanks
>>>
>>> Jethro
>>
>> My mboard supports both SATA/RAID too, and I haven't tried neither one
>> yet
>>(I have 500GB SATA but still using as external via USB2). But I don't see
>>why a faster hard drive can slow down the system.
>
> I was picturing the overheads of continuous RAID backups. The two
> drives would both go thru the MOBO components. To me, intuitively, I
> just figgered that double write would take more time than single
> write. Could I be wrong?
>
>
>>
>> I have AMD 3700+ with 3GB memory. I use it for photo post processing
>>(Photoshop) and multimedia (either converting or authoring), and often
>>have
>>several other aps running at same time. And I use "Task Manager" to
>>control
>>the speed of system by knowing which prg requires or need more CPU and how
>>each uses the CPU to control them.
>
> Hmmm
> I've never tried to use Task Manager to that end. Don't know how
> either. Maybe I should look at that.
>
> Thanks
>
> Jethro
>

On Tue, 02 Jan 2007 16:44:32 GMT, Jethro
<Wilson@somewhere.org> wrote:


>I was picturing the overheads of continuous RAID backups. The two
>drives would both go thru the MOBO components. To me, intuitively, I
>just figgered that double write would take more time than single
>write. Could I be wrong?

It doesn't take more time (negligably so anyway, with two
drives it could be that either of them takes a slight bit
longer than the other at any particular operation but it's
not worth considering in most cases).

More significant is the CPU overhead, but often when
accessing a drive the CPU is waiting for files anyway, it
has the spare time for this.

More significant is how it's implemented. If a discrete
chip sitting on the PCI bus, it's inherantly bottlenecked by
that bus, even moreso if other moderate to higher bandwidth
devices are on the same bus. For example, a typical Silicon
Image 3112 chip and a gigabit nic chip used similtaneously
(like copying files over the GbE lan to a suitably fast
recipient) would result in both sharing a little over
100MB/s available throughput.

You don't mention which RAID level though, nor the goal of
this... nor the most demanding uses... so we can't really
estimate if the pros outweigh the cons. In general on a
semi modern board with the southbridge integral RAID, the
performance factor for having the RAID is not a problem,
even of benefit if you were considering RAID0.