Ultrium 2 Speed

[John Coxeter]

I have ordered Ultrium 2 drives to speed up the overnight backups. I do not need the capacity of Ultrium 2 tapes, if I use the cheaper Ultrium 1 tapes will it slow the data transfer rate?

[Pete Randall]

John,

My references show an Ultrium 215 with a transfer rate of 25GB/hour and an Ultrium 230 with a transfer rate of 54GB/hour. Those figures assume optimal environment where the tape drive is fed data just as fast as it can handle it - no network latency, etc, etc. If you're attaching locally and can feed the drives fast enough, then yes, the speed of the "Ultrium 1" drives will be slower.


Pete

[Pete Randall]

John,

Newer references show Ultrium 215 at 54 GB per hour with 2:1 compression, Ultrium 230 at 108 GB per hour with 2:1 compression, and Ultrium 460 at 228 GB per hour with 2:1 compression:

http://h18006.www1.hp.com/products/quickspecs/11739_div/11739_div.html


Pete

[John Coxeter]

Thanks Pete

The drives are locally attached Ultrium 2
My question is will the data transfer be slower if I use the cheaper Ultrium 1 tapes on the Ultrium 2 drives, as I do not need the higher capacity of the Ultrium 2 tapes, speed is what I need.

John

[Pete Randall]

Sorry, John! Now I understand. Here's a quote from the Ultrium data cartridges
Q&A ( http://www.hp.com/products1/storage/products/storagemedia/tape_ultrium/qa.html ):

"The transfer speeds have also been enhanced, improving the peak performance. Users will also benefit from an improved recording method. Equally important, the Ultrium format Generation 2 cartridges provide users with outstanding data and investment protection because of its capability to read-and-write Generation 1 cartridges in the Ultrium format
Generation 1."

Given that, I guess I would have to say that the 2(s) will be faster than the 1(s).


Pete

[JohnWRuffo]

Hi John:

Sorry to interject here, but I had the same question you did...

The question modified itself when we asked how much can we "stream" off the disk subsystem. We did a bunch of benchmarking and found that "yes" the drives were faster, but we were not able to stream the data off the disks fast enough to reach the top end of the tape drives so it was not an issue. The Ultrium 1 would have been fine. We decided anyway to go with the 460's for the capacity.

You should use the L&TT and PAT to do some "benchmarking". If you can fulfill the buffer and throughput of the Ultrium 2 and dont need the capacity at least you would know that the decision has merit.

Take a look at this:
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50460&printver=true

You can get the PAT here:
http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareDescription.jsp?locale=en_US〈=English+%28US%29&pnameOID=12188&prodSeriesId=42846&prodTypeId=12169&basePartNum=co557&locBasepartNum=co557en&los=Microsoft+Windows+2000&tech=Software

You can get the L&TT here:
http://h18006.www1.hp.com/products/storageworks/ltt/index.html

[Vincent Farrugia]

Hello,

If you put an Ultrium 1 cartridge into an Ultrium 2 drive, the drive has to stream according to Ultrium 1 specifications. So, of course, it will run at Ultrium 1 speed, i.e., half the speed of Ultrium 2 (30Mb/s compressed instead of 60Mb/s compressed).

HTH,
Vince

[Andrew_168 · Accepted solution]

Gents,
The answers are all in the quickspecs for the product.

Ultrium 460
30 MB/s native with Ultrium 2 media (60 MB/s with 2:1 compression)
20 MB/s native with Ultrium 1 media(40 MB/s with 2:1 compression)

So the answer is yes it is slower, but still faster than Ultrium1, just!

[John Coxeter]

Thanks Andrew (and everyone) that is exactly the information I needed.