Gigabyte 333 Event - Details about SATA 6G and USB 3.0

Tradeshow & OC events by massman @ 2009-12-03

Last week we were able to escape Belgian´s rain to meet up with a lot of technical folk from Gigabyte in sunny Rome, Italy. During this presentation, we were given more information regarding the new technologies used by Gigabyte: USB 3.0, USB 3x Power and Sata 6GB.

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USB 3.0 = 10x Faster than USB 2.0

USB3.0 and USB 3x Power

The new USB standard allows users to benefit from higher transfer rates: up to 4.8Gbps (600MB/s), whereas USB 2.0 had to do with only 480Mbps (roughly 60MB/s) and USB 1.0 only 12Mbps (1,5MB/s). To translate this into a more real-life comparison, in theory, using USB 3.0, you could copy a file of 25GB from your device to the hard disk drive in 70 seconds. For USB 2.0, this will take around 14 minutes and, well, for 1.0 ... 9,3 hours.

To understand how they increased the performance, we need to have a look at the design of USB 2.0. In short, this technology uses a so-called half-duplex bus. For those who are in the unknown, duplex means that the bus can send signals from and to the receiver/sender.

In other words, the signal can be transferred from your device to the system and the other way around, all using the same data bus. The issue with USB 2.0 is, however, that this bus is only half-duplex. This means that although the bus can be used for data traffic in both ways, it only allows traffic in one way at any particular moment in time. Underneath picture should explain this:

Madshrimps (c)

Basically, when a signal is sent from device to system, the signals from system to device have to be halted until the signal from the device has arrived. Obviously, this increases the latency quite a bit and, thus, the resulting maximum theoretical bandwidth.

Now, for USB3.0, this design has changed from half-duplex to dual simplex. As you probably already figure, simplex means 'one-way street': the data bus can only transfer signals from device to system OR the other way around, but not both directions. Dual means that, for obvious reasons, there are two of those data buses. The main advantage of this design is that neither the device nor the system has to wait with sending signals.

The second three, in Gigabyte’s 333 logo, stands for 3x USB power. Basically, Gigabyte increased the available current for USB devices so that you never need two USB ports or need an external power connector to provide enough power for one device.

A normal USB 2.0 bus has a standardised current of 500mA; as USB3.0 offers a greater bandwidth, or data throughput, the standard current has been increased from 0,5A to 900mA. Now, to solve the problem mentioned a few lines earlier, Gigabyte has increased the available current for any USB device from 500mA to 1500mA (USB2.0) and 900mA to 2700mA (USB3.0).

Note that this doesn't mean that the power consumption has increased. To make it really simple: the current isn't pumped to the USB device, but the USB sucks a certain amount of current. So, this is merely an increase of the maximum available current, not by definition an increase in used current.

Another Gigabyte innovation is the increased stability for USB power. At 4.65V or lower, an USB device will stop functioning so, with the necessity of more stability due to the higher transfer rates, Gigabyte did the necessary to ensure full stability.

They have widened the voltage trace coming from the 5V line of the 24-pin ATX power connector, which lowers the impedance and for in case an USB port short-circuits, Gigabyte used one low-resistance fuse per USB port, whereas other vendors sometimes opt for one fuse per two or more ports. I have some doubts, however, regarding the necessity of these innovations. Personally, I have never experienced failing USB ports due to undervoltage, let alone have blown a fuse using the USB port. But then again, my experience with USB3.0 devices is pretty much non-existent.
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Comment from Kougar @ 2009/12/04
As USB is easier to use and can handle enough bandwidth to not completely bottleneck any data-transfer, why would we need Sata to connect harddisk drives? I presume compatibility may be an issue ... (Editor’s note : compatibility, reliability, but most important: industry standards.)
How about much lower CPU overhead?