Suggestions on improving

[eChosenOne]

I have a ACER Predator Desktop, and I want to host Jellyfin.

I have a few questions in mind.

1. With these specifications, what is the maximum number of users who can watch simultaneously with lagging?
2. Sadly, it only has two 3.5 slots for HDDs, planning to get 2 x 18TB; how many 1080p/4k shows can I store?
3. Would it be better to upgrade the casing to one that can hold more HDDs, and do I need to upgrade the power supply if I add more HDDs?

Thank you for taking the time to read.

[TheDreadPirate]

1. A lot. Without tone mapping, probably 15+. With Tone mapping, probably 6-8?
2. Can't give a definitive number. The bit rate of the video will make a huge difference. A lot.
3. As long as the parts they use are "standard" then I would suggest getting a different case with more drive slots and keeping your storage directly attached. Simplifies things a lot.

[eChosenOne]

1.  A lot.  Without tone mapping, probably 15+.  With Tone mapping, probably 6-8?
2.  Can't give a definitive number.  The bit rate of the video will make a huge difference.  A lot.
3.  As long as the parts they use are "standard" then I would suggest getting a different case with more drive slots and keeping your storage directly attached.  Simplifies things a lot.

thank you for your answer.

would there be a huge difference in enabling tone mapping? do we need to select/enable the option when setting up jellyfin?
do you have any case to recommend? and if adding more drive requires me to get a bigger power supply?

[TheDreadPirate]

If you have HDR content and your users don't have HDR compatibles devices, you will need tone mapping. To be clear, having tone mapping enabled does not affect plain transcodes. Tone mapping is the process of converting HDR to SDR. If the content someone is watching is SDR, tone mapping is not happening. There is no performance penalty for simply having it enabled. The 6-8 user number only applies to how many tone mapped streams you can handle simultaneously, worst case scenario.

I like Fractal Design cases. A couple of their models have a lot of drive sleds. They're a bit pricey, but they are well built and have a lot of quality-of-life features that makes building in them great.