TR RoboBench — Real-world transfers
RoboBench trades synthetic tests with random data for real-world transfers with a range of file types. Developed by our in-house coder, Bruno "morphine" Ferreira, this benchmark relies on the multi-threaded robocopy command build into Windows. We copy files to and from a wicked-fast RAM disk to measure read and write performance. We also cut the RAM disk out of the loop for a copy test that transfers the files to a different location on the SSD.
Robocopy uses eight threads by default, and we've also run it with a single thread. Our results are split between two file sets, whose vital statistics are detailed below. The compressibility percentage is based on the size of the file set after it's been crunched by 7-Zip.
|Number of files||Average file size||Total size||Compressibility|
The media set is made up of large movie files, high-bitrate MP3s, and 18-megapixel RAW and JPG images. There are only a few hundred files in total, and the data set isn't amenable to compression. The work set comprises loads of TR files, including documents, spreadsheets, and web-optimized images. It also includes a stack of programming-related files associated with our old Mozilla compiling test and the Visual Studio test on the next page. The average file size is measured in kilobytes rather than megabytes, and the files are mostly compressible.
RoboBench's write and copy tests run after the drives have been put into a simulated used state with 30 minutes of 4KB random writes. The pre-conditioning process is scripted, as is the rest of the test, ensuring that drives have the same amount of time to recover.
Read speeds are up first. Click the buttons below the graphs to switch between one and eight threads.
The 750 Series scores a rare victory over the P3700 in the eight-thread media test, but its advantage is slim, and the two NVMe drives are otherwise closely matched. They have sizable leads over the competition in all but the single-threaded work test, where all the SSDs are tightly bunched.
Samsung's XP941 is by far the biggest threat overall. It nearly catches the 750 Series in the multi-threaded media test, and it's clearly the faster of the PCIe alternatives.
Next, we'll look at write speeds.
Score another win for the 750 Series, this time in the single-threaded work test, where the stakes are admittedly low. The P3700 regains the lead when the thread count increases, and the XP941 almost sneaks into second place. Samsung's M.2 drive is nowhere near the NVMe duo in the media tests, though. Write speeds are much higher in those tests, and so are the gaps between the 750 Series and its neighbors.
Last, but not least, we'll see what happens when reads and writes collide in copy tests.
Reading and writing simultaneously produces an exaggerated version of the pattern established in the previous tests. The 750 Series and P3700 have comfortable leads throughout, and their advantages are especially pronounced in the media and eight-thread tests.
Once again, the closest competition is the XP941. Closest doesn't necessarily mean close, though. The Samsung drive copies media files at almost half the speed of the 750 Series, and it's over 100MB/s behind in the multithreaded work test.