[Tig] Minimum RAID bandwidth for 2K playback?

[Bob Kertesz]

> * Real world you may not get either of these numbers from the drives so don't 
>always count on those numbers. Testing with your application, OS and 
>additional hardware will be the only real numbers you can trust.  There may 
>be a bottleneck in any of these preventing you from getting close to the 
>theoretical numbers the drives can give. Unless you know how to get around 
>them your stuck.

Boy, no kidding.

I have a situation here where I have an AJA 2K in an older but highly
recommended (by both AJA and Decklink) motherboard, using an Adaptec dual
channel U320 controller, driving 8 Seagate U320 15K spindle drives in Raid 0,
and no matter what I do, I am unable to achieve a constant data rate higher
than about 250 Mb/s, which is about HALF what I expect to see from the
combination. The drives are older (two generations back from the current
generation of drives), and that may have something to do with it.

Now 250 Mb/s is fast enough for uncompressed 10 bit 4:2:2 at 1080, but not by
much. To go to 2K or 4:4:4, I need much better speeds, and I'm not going to
get that with this combination.

Hence my quest for something better but *affordable* for a box I'll use maybe
20-30 days a year.

--Bob

Bob Kertesz
BlueScreen LLC
Hollywood, California
bob at bluescreen.com

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