IOPS or THROUGHPUT for screen capture

Goowpea · October 21, 2020

Hi all,

Game streaming and game recording is currently blooming like crazy (most probably due to pandemic) and new streamers and tubers are popping like mushrooms (including myself - no shameless plug in this post). I was curious and started wondering.

Nowadays we can screen capture up to 8K which gives an INSANE amount of data. Even regular 1080p can give you over 30GB file from capturing 30 minutes of gaming on high settings.

What is more important in case when it comes to writing these massive amounts of data?

Is SATA III HDD enough or is it a bottleneck for the system? Should we invest in a very spacious SSD to get out game capture written on it? If yes then what is more important? Throughput or IOPS?

We currently can get PCIe 4.0 NVMe SDD that has over three times the IOPS of a PCIe 3.0 NVMe SSD, but "only" double the speed.

I would assume that throughput is more important than IOPS since recording is a continuous task that doesn't require drive to search for data, but maybe there's someone that could confirm (or deny) my assumption?

WereCatf · October 21, 2020

15 minutes ago, Goowpea said:

Even regular 1080p can give you over 30GB file from capturing 30 minutes of gaming on high settings

That'd still be only ~17MB/s (30GB / 30 minutes = 1GB/min ~= 17MB/s), so not a terrible amount.

15 minutes ago, Goowpea said:

Is SATA III HDD enough or is it a bottleneck for the system? Should we invest in a very spacious SSD to get out game capture written on it? If yes then what is more important? Throughput or IOPS?

8K - resolution is 16 times 1080p, so with the above number in mind, 16 * 17MB/s = 272MB/s -- that's still easily handled by a SATA SSD. Obviously, it depends on the bitrate and codec you're using for recording, but no, SATA SSD is unlikely to be a bottleneck even for 8K - recording, unless you're doing lossless.

As for IOPS or throughput: recording is a wholly sequential tasks, so IOPS doesn't really matter, unless you're recording multiple streams to multiple files simultaneously.