Benchmarks: CrystalDiskMark 3.0
The SSD 850 Pro's sequential read performance was the strongest we've recorded for a SATA SSD at 538MB/s. Enabling RAPID mode inflated the results showing a transfer rate of 7.2GB/s. Even the first run delivered well over 6GB/s and this is because synthetic benchmarks like CrystalDiskMark pre-cache all the benchmark files onto the target drive first. So essentially RAPID mode is measuring is RAM performance here.
The sequential write performance is also very strong at 502MB/s, while RAPID mode offered an inflated 4.3GB/s.
The SSD 850 Pro's random 512K performance wasn't as strong as we expected, hitting just 407MB/s, while the SSD 840 Pro managed 477MB/s. Enabling RAPID mode again produced an unrealistically high 6.8GB/s.
The random 512K write performance was comparable to the older 840 Pro with 469MB/s.
Back when we tested the SSD 840 Pro we found its random 4K-QD32 performance (as you can see, it produced 294MB/s) but the 850 Pro improves on that figure a more respectable 333MB/s, while RAPID mode took that to 449MB/s.
The random 4K-QD32 write performance of the SSD 840 Pro was also particularly weak with a throughput of just 223MB/s and the 850 Pro corrects this performance with 325MB/s making it one of the faster SSDs we have tested here.