I am using an 840 Pro and Samsung Magician performance benchmark is around 550MB/s read and 350MB/s write. Will I see any improvement if I upgrade to an 860 Evo? The 840 Pro is out of warranty, but has few TB written. Should I expect it to fail any time soon?
Maybe a bit on the write performance, but SSD's on current SATA 3 interfaces are hitting the limit. Only NVMe can provide more growth for SSD's.
The 840 Pro has been tested to destruction and is proven to have ridiculous longevity. It will last longer than you! I also run an 840 Pro and 850 Evo, they have almost identical performance. Write is always slower than read except for 4K Q1T1. My 840 Pro read is the same as yours, write speed is 439MB/s. (6700K on Z170 Maximus Hero mobo) Its likely your SSD is in use a bit while testing. As stated, max performance cannot go much higher because you are at the limit of SATA. There is little to gain unless you move to NVME, but even then it has limits. NVME drives are still not much faster except with large file transfers, where they are a LOT faster - as long as the drive they are copying from/to can run that fast as well. Gaming performance sees little difference.
Got a 840 Pro here as well. Since 2015, taken from a business machine where it was used as SQL storage. Right now it's raided, so I cannot tell you the single per, but RAID0 is about 800 - 850MB/s steady until some GBs written. Then it drops a bit. But runs without errors since 2015. Pro for 860 EVO seems to be the adjustable SLC cache. Downside is the QLC version, which drops to 150MB/'s when out of SLC cache. The non-QLC version only drops to 350 - 400 I think. (I never had one, just read through the tech specs.) But I don't think you will notice a difference between 840 and 860.
