Value of 4K Read?

[camieabz]

I was looking at potential upgrade options for my old Samsung 840 Evo 250GB SSD (I prefer Samsung btw).

Based on availability and pricing, the two options that seemed most applicable are:

860 Pro 256GB
850 Evo 500GB

Both are with £5 to £10 of one another, so short of some surprise delivery cost, not an issue. So then I compared them both with my 840, using it as a baseline:



(Yes, I missed that I had the 860 Pro down as 250GB Evo and not 256GB Pro in the legend.)

So the 860 is pretty much the way to go if performance-only is on my mind, while if I'm desperate for the 500GB capacity, the 850 is the best option. However, I noticed the 4K read results for the 850 and 860, and I presume that the increased capacity allows for better 4K reads for the 850 (charts 1 & 2, and ADQ Read in chart 3).

UserBenchmark states:

4K random read is a disk access pattern whereby small (4K) blocks of data are read from random locations on the surface of the device being tested. The term is used primarily within the context of benchmarking and the speed which it is usually measured in, MBps, can be thought of as how effective a device is at quickly retrieving small pieces of data from random locations. This type of access pattern is very common during operating system startup, where lots of configuration and driver files must be read from the disk. Drives that are used to host operating systems will perform much better if they are able to sustain high random read speeds. As a rule of thumb approximately 20% of a typical users overall disk access on a PC will consist of random reads.

So does that mean the 860 will be better in the other 80% of disk activity, or does it come down to a user's usage habits, i.e. more desktop, than Workstation, or gaming?

Does anyone have an in-depth (reasonably easy to understand) link or two, to expand on SSD inner workings and real world usage?

By the way, short of a massive increase in my demand for capacity, I would opt for the 860. Just curious.

 

[gasaraki]

If I had to choose between a 850EVO 500GB or a 860EVO 256GB, i would go with the 850EVO with the bigger size. The performance difference is not enough to justify the lost of 50% of drive space.

 

[Eximo]

Random 4K is more close to everyday use. The computer doesn't know you are going to click on something in the start menu. Large sequential data is only when transferring large files (or game map loads)

Really either would be fine. If you want capacity, go for it.