New Data Transmission Speed Record

An anonymous reader writes "Gizmag is reporting that a team of German and Japanese scientists have collaborated to shatter the world record for data transmission speed. From the article: "By transmitting a data signal at 2.56 terabits per second over a 160-kilometer link (equivalent to 2,560,000,000,000 bits per second or the contents of 60 DVDs) the researchers bettered the old record of 1.28 terabits per second held by a Japanese group. By comparison, the fastest high-speed links currently carry data at a maximum 40 Gbit/s, or around 50 times slower."

Comments

Why is bandwidth measured in Kb

[b00m3rang]

and storage in KB? It's not like we measure radio waves in cycles per second and sound waves in cycles per 8 seconds. What's the advantage?

Filesystem and Ultra320 SCSI are our chokepoint

[PSaltyDS]

We have a 30TB EMC CX-500 with Brocade 2Gb FC backbone. The bench moves blocks of a few hundred GB to a dozen servers or less. We have never come anywhere near %50 utilization on the FC.

The transfers run about 4-6hrs and I was looking for choke points to shorten the time. The data simply won't go to disk any faster on the U320 SCSI bus. We consistently measure 20MBps max to disk, which makes sense. U320 means 320Mbps/8 = 20MBps. So I get the same max numbers for local disk-to-disk that I get for SAN-to-disk, and the same results regardless of OS. If this rate could be maintained, six servers doing the transfer should just about saturate the backbone, but the overhead of file access and FS management mean the max is only maintained for a moment as a few particularly large files come across. With lots of smaller files being copied, the average rate goes down to 2MBps.

If these servers had to be optimized for SAN-to-Disk transfer rate, they would have to have multiple SCSI controllers and HBAs, paired up on seperate PCI busses, and the data would have to be optimized with fewer/larger files.

Of course, the 2.5TBps link is of interest to ISPs and regional carriers not server labs, but I thought I'd throw in what we've seen on the utilization of a 2Gbps FC link in a SAN setup.