[mythtv-users] recommendations for building new FE/BE HDTV system?

[Gordon McCrae]

Brian Wood wrote:
> On Sunday 05 April 2009 12:55:08 you wrote:
>
>   
>> The simple reason why it's faster is that this is what RAID-0 is
>> designed to do; it stripes the data across multiple disks so that you
>> get them running in parallel, all transferring data (up to your bus
>> limits of course). So whenever access a file from a RAID-0 array it
>> actually read parts from each disk in parallel, thus reducing the time
>> you need to wait for it. In theory it could be as much as twice the
>> speed, but reality kick in with overheads, bus bottlenecks etc. and
>> reduces it below that.
>>     
>
> I understand that, but I would have expected a two-drive array to have approx. 
> twice the speed of a single drive, not close to 3 times the speed.
>
> I'd guess that the RAID sub-system probably caches things to some extent, 
> resulting in some performance gain, but I don't know the details.
>
>   
>> As to whether it's wise to do it, that's entirely up to the individual.
>>     
>
> That's why I made sure to include the down side as well as the positive 
> factors in my post.
>
>   
You're correct, sorry I didn't notice you'd stated seeing better than 2x
performance gain.

This shouldn't be feasible (not purely with 2 disk striping anyway).

The most obvious gotcha when testing this sort of thing is to ensure the
file you're copying isn't cached the second and subsequent time, could
that be a factor for you?

Cheers
Gordon