SSD vs HDD for high usage and long time use

Solution 1:

The Total Bytes Written (TBW) is an indication only and does not mean that the disk cannot continue much beyond that value. The SSD has a large reserve of replacement cells, and will normally enter a read-only state only when that reserve is exhausted.

First false assumption : Do not assume that 1 GB written to the disk equals 1 GB out of the TBW, because large sector size may mean that the real value is up to 2-3 times that.

Second : Do not also assume that the TBW equation only includes data that you write, since the SSD also constantly juggles data internally due to static data rotation and garbage collection routines, so there is always a constant stream of wear inside the SSD, even if you are not actively writing data to the drive.

The article SSD Endurance Experiment has shown that good-quality (and costly) SSDs may exceed their TBW by some petabytes, but that some others may fail much sooner.

An SSD under such constraints as yours will need periodic checks of its S.M.A.R.T data, and has better be scraped the moment write errors start to appear. I also wouldn't count on the disk locking itself in read-only mode without any data being lost, or on how much time it will take you to understand what all those disk errors mean, since you will not get any more meaningful messages from the operating system when the disk enters read-only state (a system drive will then simply fail to boot).

It is impossible to predict the quality of your SSD. Given your volume of writes, your SSD may last anything from 6 months to a year, or 2-3 years if it is much better than its rating. But I wouldn't advise you to plan on it.

In short, perhaps an SSD is not the best solution for your needs and is too chancy, given your environment.

Solution 2:

In a scenario like this, you really, really want two drives. Check whether your laptop has an mSATA or m.2 slot where you can have a small SSD in addition to your larger HDD.

The reason is that video streaming is sequential access to very large amounts of data. This isn't a problem for an SSD apart from the write endurance problem, but it is also the absolute best case for a rotating disk (keep it defragmented) because it can just write or read data continuously in a fixed order without having to seek. Minimal head motion means no time wasted waiting for the seek, lower power consumption, lower heat, lower noise, longest life, best performance. Inexpensive SSDs have little performance benefit over the sequential access performance of a modern HDD (> 100 MB/s).

The problem arises when you have a multitasking OS. Some background task will want to access something other than the video, and then the continuous disk access is interrupted by the need to seek between the video and the other data. This will cause the HDD performance to plummet, random access speeds are often < 0.1 MB/s.

If you get a lower capacity second disk (and because SSDs are physically smaller, a laptop is far more likely to have space for both SSD and HDD but not two HDDs), then the OS and applications can go on the SSD, and the HDD can be dedicated to the video streaming. This will allow the HDD to operate almost exclusively with sequential access patterns (when the file size grows, updates have to be made to directory data as well as file contents, but video-processing applications should be smart about growing the output file in large chunks and infrequently).