[mythtv-users] RAID versus Drobo

[Eric Robinson]

Brian Wood wrote:
> Eric Robinson wrote:
>   
>> Wade Maxfield wrote:
>>     
>>>> I guess my question about the Drobo really boils down to the
>>>> throughput.  Is USB 2.0 fast enough for HD content storage in a Myth
>>>> setup with multiple Frontends?
>>>>
>>>>     
>>>>         
>>> The question isn't if USB is fast enough, it's whether the Drobo is 
>>> fast enough. You might want to check out a review of a Drobo, the USB 
>>> 2.0 bus doesn't seem to be the limiting factor in throughput.
>>>
>>> http://arstechnica.com/reviews/hardware/storage-robot-at-your-service-a-review-of-the-drobo.ars
>>>
>>>   - Wade
>>>   
>>>       
>> Very true.  Tom's Hardware did a review of the thing a while back, too,
>> and even have a spiffy little graph to show the speeds.
>>
>> http://www.tomshardware.com/2007/06/27/meet_drobo/page10.html#performance
>>
>> It appears that reads and writes tend to stay under 20 Mbps.
>>
>>
>>     
> Wow! That's pretty dismal. I get better performance from my Linksys
> NSLU2 (aka "slug").
>
> Have a look at this:
>
> http://library.creativecow.net/articles/gerard_rick/premiere-pro-HD.php
>
> Of course if you plan to record one stream while watching another,
> record multiple streams, or do anything else requiring disk I/O at the
> same time you'll want more than that chart implies.
>   
Umm... If you're pointing to the graph on that page then it's a little
different.  That's completely Raw HD.  Nothing in MythTV is done in
Raw.  My understanding is that it's Mpeg2 generally and can be converted
using Mythtranscode to some version of mpeg4.  In any event, I figure
MythTV buffers a certain portion of the video on the frontend before
beginning to play in case of heavy network jitter.  One hour of 1080p
content is 7GB or so, right?  I feel like I read that somewhere in the
docs...  Anyone have any success stories with playing back HD content
and with what drive interface speed?