Your speeds are slow....you should expect the LTO4 drives to run roughly 105-110MB/sec optimally w/out compression. The drive is spec'd at 120MB/sec but you will give up around 10% for ISV overhead. Keep in mind this is an optimal setup. Slower performance will result as you introduce bottlenecks.. ie. network backups, slower servers.  Nothing in the ML6K will hold it back from running these speeds w/ 1 drive or 16drives simultaneously , any throughput issues will be coming upstream ie. server environment. The drives are cabled separately, so SAS drives will be on a different bus, Fibre drives can be on a separate bus or zoned to be run off a single HBA, scsi drives can also be separate or daisy chained. If you describe your setup for the FORUM folks may be able to offer some suggestions for you to tweak to get closer to the optimal mark. support.dell.com has a tool ITDT you can DL to test performance. It should be listed under the ML6K product.   Bob
What are reasonable and expected Job Rates to see in Backup Exec on an ML6000 with two LTO4 drives?  Within the last two days (and this is pretty constant for the last two months), I see everywhere between 1.00MB/min (it took 5:53:25 to backup 660,896,312) to 3,280MB/min (it took 00:01:52 to backup 917,181,476).  Those rates are for the same drive. I've never used a dual drive tape library before.  Does the ML6000 have a dedicated bus for each drive, or do both drives share the same bus?  We have an ML6000EM waiting to go in with two more drives.  What is the bus situation on that?  Will it be sharing the same bus with the current two drives?
ML6000 throughput?