OSNews > Thread > "RE[3]: Comment by Macrat" by umccullough

Linked by Thom Holwerda on Mon 17th Nov 2008 19:18 UTC

Unveiled on Monday by the USB Implementers Forum, the USB 3.0 spec can theoretically support data-transfer speeds of up to 4.8Gbps - 10 times the speed provided by USB 2.0. The new standard, also known as SuperSpeed USB, is also expected to be more power-efficient than its predecessor. "SuperSpeed USB is the next advancement in ubiquitous technology," Jeff Ravencraft, the president of the USB Implementers Forum (USB-IF), the industry group that promotes USB technology, said in a statement on Monday. "Today's consumers are using rich media and large digital files that need to be easily and quickly transferred from PCs to devices and vice versa. SuperSpeed USB meets the needs of everyone, from the tech-savvy executive to the average home user."

4 23 Comment(s)

http://osne.ws/fuo

Thread beginning with comment 337493
To view parent comment, click here.
To read all comments associated with this story, please click here.

RE[3]: Comment by Macrat

by umccullough on Tue 18th Nov 2008 00:06 UTC in reply to "RE[2]: Comment by Macrat"

Member since:
2006-01-26

Whether or not the B is capitalized makes a factor of 8 difference! bps is bits per second. Bps is Bytes per second. There are 8 bits to a Byte. USB 2.0 supports a theoretical 400 Mbps, therefore a theoretical 50 MBps. So, if you're seeing 12 MBps this is on the order of 25% of the theoretical maximum, and makes good sense.

Realistically though, with overhead of the protocol (control bits, etc.) a serial bus throughput usually boils down to a fraction of 10 anyhow.

Thus, 480Mbps (the actual alleged throughput of USB2, not 400 as was indicated) usually ends up with ~48MB/sec maximum... I'm not sure I've ever seen it hit this amount anyway

Reply Parent Bookmark Score: 3

RE[4]: Comment by Macrat

by leech on Tue 18th Nov 2008 01:13 in reply to "RE[3]: Comment by Macrat"

Member since:
2006-01-10

I was thinking that too, it isn't 400Mbps, it's 480Mbps.

Back when USB 2.0 was coming out, I had a discussion (really more like an argument telling a person how stupid he is) about USB 2.0 and Ultra SCSI 160.

I believe his exact words when I told him I was building a system with Ultra SCSI 160 drives, "you're jumping on the bandwagon a little late, USB 2.0 is going to crush SCSI." Yeah, and when did that happen?

He failed to understand that 480Mbps is not the same as 480MBps, and that 160MBps throughput of the Ultra160s would crush USB2.0

Reply Parent Bookmark Score: 3