Multithreaded Read & Write Patterns
The multithreaded tests simulate a situation when there are one to four clients accessing the drive at the same time – the clients’ address zones do not overlap. We will discuss diagrams for a request queue of 1 as the most illustrative ones. When the queue is 2 or more requests long, the speed doesn’t depend much on the number of applications. You can also click the following links for the full results:
Multithreaded reading is an easy load for SSDs due to the way they store data. An SSD does not care what memory cell to read data from if the requested data block is large enough for multi-channel access. There are some differences in the practical test, though. The Intel X25-M delivers the highest performance and even gets faster when reading multiple data threads. Corsair’s models slow down at two and three data threads. When reading four threads, the X128 goes ahead suddenly as if this is just the right kind of load for it. The P128 does not accelerate that much.
The JMicron-based products slow down with each added thread although not as quickly as HDDs usually do.
When doing multithreaded writing, the SSDs behave in the same way as in the multithreaded reading test. The only exception is Intel’s X25-M which maintains the same speed irrespective of the number of data threads. The Corsair SSDs slow down with the addition of a second thread but accelerate when more threads are added. The JMicron-based products are steadily losing their already low speed as we add more and more data threads.