We've got a bunch of 9940B drives and use 262144 for SIZE_DATA BUFFERS.  
Performance is very good.  When we eval'd the drives a couple of years 
ago, I saw peak performance of 65MB/sec on really compressible data.  
Our numbers vary widely depending on the nature of the data being backed 
up.  From the docs I read, I believe the drive maxes out at 70MB/sec.

If you can feed the drives compressible data in a constant stream, 
50MB/sec is not unreasonable.

I like the performance stats on the new T10000 drives, but I'm very 
disappointed that they didn't build in read compatibility with the T9940 
drives.  The carts are completely incompatible.  If we're going to have 
to do a data migration if we get new drives, might as well look at LTO, too.

David Rock wrote:

>* Clooney, David <david.clooney at bankofamerica.com> [2006-10-14 15:19]:
>  
>
>>Keep your hair on Bob
>>
>>Ok so tyou know about drives, point taken.
>>
>>I think you misinterpretted my mail.
>>
>>I was merely trying to find out the maximum I/O the drive supports ,
>>phew.
>>    
>>
>
>We have seen real world testing at 55MB/sec and I believe the rated
>speed is around 65MB/sec
>
>  
>


-- 
Jack L. Forester, Jr.
UNIX Systems Administrator, Stf
Lockheed Martin Information Technology
(304) 625-3946