[LTO3 blocksize?] bs= speed= 32k 50482 kps 128k 50531 kps 256k 50508 kps 512k 50521 kps 1024k 50512 kps 2048k 15780 kps 4096k 15875 kps
I am in a similar situation with Quantum LTO-2 drives. I am using 32k blocksize, and my testing indicated that even at 512k the speed fell off from the max. I am seeing 23 MB/s write speed at the peak, and it's pretty consistent and the drive sounds good at that speed. I realize this is slower than the 40 MB/s that LTO-2 is supposed to do. This is with dd from /dev/zero, and an Adaptec 2940U2W with only the tape drive on the bus. I didn't run amtapetype - I just grabbed one. I've only written 50G max of 200G allowed, and usually less so I'm not worrying. On NetBSD and probably *BSD, 'systat vmstat' shows IO speed per device.
