Asus Delivers Speed Boost With USB Attached SCSI Protocol

MojoKid writes "When USB debuted in 1999, it offered maximum throughput of 12Mb/s. Today, USB 3.0 offers 4.8Gb/s. Interestingly, modern USB 3 controllers use the same Bulk-Only Transport (BOT) protocol that first debuted in 1999. Before the advent of USB 3, relying on BOT made sense. Since hard drives were significantly faster than the USB 2 bus itself, the HDD was always going to be waiting on the host controller. USB 3 changed that. With 4.8Gbits/s of throughput (600MB/s), only the highest-end hardware is capable of saturating the bus. That's exposed some of BOT's weaknesses. UASP, or the USB Attached SCSI Protocol, is designed to fix these limitations, and bring USB 3 fully into the 21st century. It does this by implementing queue functions, reducing command latency, and allowing the device to transfer commands and data independently from each other. Asus is the first manufacturer to have implemented UASP in current generation motherboards and the benchmarks show transfer speeds can be improved significantly."

Does SATA fit into the mix anymore?

[jabberw0k]

With UASP sufficient to provide a good disk interface, will new motherboards keep it simple and eliminate the SATA controller and ports? Will new internal hard drives simply have USB connectors?

According to Electronic Design [electronicdesign.com],

Using a common command set reduces support and compatibility issues. SATA flash and hard drives support a subset of SCSI, which is why SAS controllers can easily handle SATA and SAS drives. This also makes support of these drives via UASP significantly easier. Likewise, it means standard device drivers for operating systems like Windows and Linux work with all devices.

So, a kernel could have a single SAS driver that supports all SAS, SATA, and USB block devices. This could be a marvelous convergence.

Re:Does SATA fit into the mix anymore?

[Lord_Naikon]

So, a kernel could have a single SAS driver that supports all SAS, SATA, and USB block devices. This could be a marvelous convergence.

I know FreeBSD does that, using the CAM (Common Access Method) subsystem. Presumably other OSes do something similar.

Great for audio

[dontmakemethink]

This finally resolves the biggest problem for USB interfaces and hard drives for audio. The primary factor for performance in audio has always been access speed (seek time), and not throughput. Audio software has to access dozens of separate audio files in a very timely manner frequently, and the overhead of the USB protocol has always been a wrench in the gears. From what I'm reading, UASP offers the same advantages NCQ (Native Command Queuing) offers in SATA, which allowed for much higher track counts on the same drive rather than spreading files across several drives, which was a pain in the butt. It was only with NCQ in ~2005 that SATA finally caught up with SCSI-2 (ca 1994) in audio performance, provided the drive was 7200rpm or faster. Firewire has some form of queuing system built into the host, so it's always been better than USB for audio, but it is vanishing from laptops and desktop motherboards, even Apple products.

Now watch how long it takes before audio hardware manufacturers adopt it, and feel our pain. The first Firewire audio interfaces came out about 4 years after Firewire was standard on Mac desktops...

Re:USB as RAM?

[TheGratefulNet]

search for 'vertical usb flash' and you can find internal tiny usb 'thumbdrives' that mount right on the 10pin (iirc) usb mobo header. inside the case. has been that way since about the start of vista days (1gb was somewhat common as a 'cache' you could use).