USB 3.0 Performance
We measure the speed of the USB 3.0 interface using CrystalDiskMark 3.0 and an external Buffalo DriveStation HD-HX1.0TU3 drive. The diagram below shows the results of all mainboards with USB 3.0 we have tested so far and we can see them all split up into two groups. One group delivers higher USB 3.0 performance. These are the Socket AM3 models which USB 3.0 controller is connected to a PCI Express 2.0 bus and the LGA1156 mainboards with Intel chipsets where the USB 3.0 controller is connected via a PLX bridge. The Intel-based mainboards without that bridge connect the controller to a first-generation PCI Express bus which limits their USB 3.0 bandwidth. The results are sorted by read speed but we can see the same thing at writing. The ASRock H55 Extreme3 is the only exception, but it implements USB 3.0 with a Fresco Logic FL1000G controller rather than with a NEC D720200F1 chip as in the rest of the mainboards, which must be the reason for the difference.
The ASUS P6X58D-E doesn’t need any extra bridges or other tricks to implement USB 3.0. The flagship chipset Intel X58 Express has free second-generation PCI Express lanes whose bandwidth is high enough for the USB 3.0 controller to deliver its best performance.
We performed our power consumption measurements using an Extech Power Analyzer 380803. This device is connected before the PSU and measures the power draw of the entire system (without the monitor), including the power loss that occurs in the PSU itself. In the idle mode we start the system up and wait until it stops accessing the hard disk. Then we use LinX to load the Intel Core i7-930 CPU. For a more illustrative picture there are graphs that show how the computer’s power consumption grows up depending on the number of active execution threads in LinX (both at the default and overclocked system settings). We performed the test in four modes: idle mode, single-thread load, four-thread and eight-thread load.
Of course, the system consumes more power when overclocked, but the considerably increased performance makes up for that.