It was also distinguished by a relatively high data transfer rate: 3 megabytes per second. This was because it was able to read and write linear data across 18 recording tracks simultaneously, or of tape. IBM's prior technology employed 9 recording tracks with a data density of of tape, so the 3480 format was greeted as a major breakthrough. The IBM 3480 cartridge stored 200 megabytes in a modest cartridge compared to the previous technology's 140 megabytes on a diameter ( length) reel of tape. The 3480 and its successors are streaming drives. The 3480 was initially a disaster, because it would consistently underrun as the 3 MB/s bus and tag channels and the 3 MB/s drives could not feed the 3MB/s second tape drives because of various interferences such as seeks. The streaming drives would then have to stop, back up and restart, reducing throughput to under 200 KB/s.