PCMark 8 was originally introduced in 2013 and the storage test uses only one thread to do everything. We are by no means living in the single-core era thanks to corporations like AMD offering CPUs with higher core counts than ever before. PCMark 10 Storage uses all the CPU cores available on the platform being tested and has been validated to support up to 5GB/s bandwidth. About half the available cores/threads are being used for generating the data needed for I/O and the other half are tasked with sending out I/Os. The I/O in both PCMark 8 and PCMark 10 is asynchronous. That means that the thread sending an I/O does not sit waiting for it to complete, but can instead queue more I/O to match the queue depth in the recorded trace. The CPU thread count used by the benchmark does not equal to the queue depth seen by the storage device. Most modern software has been written to be a muilthreaded solution where it can push IOs from multiple threads. This should play top the strengths of NVMe devices that have come out in recent years as they were designed to handle multiple queues at the same time. So, the take home message here is that PCMark 10 takes advantage of all available threads and uses newer real-world traces.
The Data Drive Benchmark is designed to test drives that are used for storing files rather than applications. You can also use this test with NAS drives, USB sticks, memory cards, and other external storage devices. The Data Drive Benchmark uses 3 traces, running 3 passes with each trace.
On the PCMark 10 data drive benchmark the WD My Passport SSD (2020) 1TB portable SSD finished with an overall score of 1277 points, which is a new record for this AMD X570 platform powered by the AMD Ryzen 5 3600X processor running at stock speeds. This is a very impressive final score and we finally found a drive that is able to compete with the Crucial X8 1TB drive on PCMark 10!
The PCMark 10 Storage Benchmarks overall score is calculated from the bandwidth and average access time sub-scores. The bandwidth subtest is defined by UL in PCMark 10 as bandwidth = bytes / busy_time_for_read_and_write. The results here showed that the WD My Passport 1TB portable SSD averaged 196.0 MB/s during this trace test, which is nearly 77% faster than the WD My Passport SSD from 2018. A very significant speed improvement over two years that was fueled by the move to an NVMe based SSD and bridge chip inside the drive.
The final subtest result is the average access time. During a trace playback in PCMark 10, the start and end time is measured for each I/O. So, the average access time is derived from the end time of an I/O subtracted from the start time of that operation. An average access time of 126 microseconds was found on the WD My Passport 1TB (2020) external drive. This is 100ms less than the access time on the WD My Passport SSD 1TB model from 2018!