|ASUS P8Z77-V Deluxe Benchmark Performance|
|Reviews - Featured Reviews: Motherboards|
|Written by David Ramsey|
|Monday, 23 April 2012|
Page 10 of 13
ASUS USB 3.0
Since the introduction of USB 3.0, aka "Superspeed USB", in January of 2010, motherboards have implemented this feature using third-party controllers from companies like NEC, Renesas, and ASMedia. Each port supplied by one of these controllers required a PCI-E lane from the motherboard's chipset, which, while workable, reduced the already limited number of PCI-E lanes available on LGA1155 motherboards.
With the Z77 Express chipset, Intel finally gives us four native USB 3.0 ports, none of which require an extra PCI-E lane. However, on the P8Z77-V Deluxe, ASUS also includes four additional USB 3.0 ports, courtesy of two ASMEdia ASM1042 controllers. While these could limit the use of other ports on the motherboard (like the extra SATA6G ports), ASUS also includes a PLX Technology PLX8608 chip, which provides an additional eight PCI-E Gen 2 lanes, so you don't have to worry about "stealing" lanes from other functions of the motherboard.
But where it gets interesting is ASUS' USB 3.0 Boost feature. You see, standard USB protocol is called BOT or "bulk-only transport." This protocol was created in 1999 with the original USB spec and designed to support USB 1.1, which had a transfer rate of 12 million bits per second...a bit slower than USB 3.0's 4 gigabits per second. With BOT, SATA6 SSDs connected to a standard USB 3.0 port couldn't deliver anywhere near their rated performance.
ASUS improves on bulk-only transport in two ways, both under the umbrella term USB 3.0 Boost: for USB 3.0 ports connected to the ASMedia controllers, ASUS implements USB Attached SCSI Protocol, aka UASP, as well as their own "Turbo" protocol. Which protocol is used depends on the device you connect, since not all devices support UASP.
For USB ports connected to the Z77 Express chipset, "Turbo" is the only choice since Intel's USB 3.0 controller doesn't support UASP just yet. When you enable USB 3.0 Boost in ASUS' AI Suite utility, the faster protocols are used automatically when a compatible device is connected.
So how much of a difference does USB 3.0 Boost make? To find out, I used an Intel SSD 520 series 240GB SATA6 SSD connected to the P8Z77-V Deluxe's USB 3.0 ports via a USB 3.0 SATA dock. Let's start with AIDA64's built-in disk test utility and check out the read performance.
Connected to the Intel USB 3.0 port, the Intel SSD turned in 294 megabytes per second with USB 3.0 Boost off, and 425.6 megabytes per second with USB 3.0 boost on. That's a 45% increase! On USB ports connected to the ASMedia controllers, the read rate isn't as fast, but even so, turning on USB 3.0 Boost gives a 24% performance boost. Let's take a look at the transfer rates in the ATTO disk benchmark:
For the ASMedia controller, we see decent read and write speeds maxing out at 256 MB/s and 291MB/s, respectively. Now let's try it with USB 3.0 Boost:
Read and write maximums increase to 336MB/s and 385MB/s, respectively. Now for the Intel controller's standard performance:
And boosted with ASUS' "Turbo" protocol:
Here we see another huge increase, from standard read and write maximums of 270MB/s and 302MB/s to 431MB/s and 410MB/s. Follow me to the next section as I continue to benchmark this feature.