We measure the system USB 3.0 performance by using the excellent Patriot SuperSonic Magnum 256GB USB 3.0 drive, which we reviewed back in February this year.
Performance via the USB 3.0 ports is excellent, scoring almost 260 MB/s and 177MB/s in sequential read and write tests.
Due to the nature of this kind of flash, and via the USB 3.0 interface, 4k and 4k QD32 performance is substantially worse than from a native SSD drive across a SATA connector.
The ATTO Disk Benchmark performance measurement tool is compatible with Microsoft Windows. Measure your storage systems performance with various transfer sizes and test lengths for reads and writes. Several options are available to customize your performance measurement including queue depth, overlapped I/O and even a comparison mode with the option to run continuously. Use ATTO Disk Benchmark to test any manufacturers RAID controllers, storage controllers, host adapters, hard drives and SSD drives and notice that ATTO products will consistently provide the highest level of performance to your storage.
The ATTO Disk Benchmark shows similar results in the read test, peaking at 260 MB/s. The write performance results are much lower however, dropping to around 65 MB/s.