-- Have you ever self hosted a Linux/Free Bsd server at home?
-- What was the maintenance like in terms of operation and cost compared to an online service?

I and my partner are planning to self host our Ubuntu server locally because currently though we spend less than $1100 a month on Azure with moderate CPU usage but we plan to scale out with believes that the server cost might sky-rocket.

We made a budget of $25k for the setup which includes cost of hardware, bandwidth and power.

We also made some research concerning most used hardwares for home servers because we really are newbees talk of hardware. What we found are options related to the Intel Xeon as CPU, some others say use NAS, while some are more of advertising.

$25k on the desk,
we care more about speed than of space. How can we make the setup totally worth it? You don't have to spare us a change, just some headlight and way to go.
Your advice are needed. Thank you.

It depends how much you value your time.

If you don't ascribe a $ value to it, then hosting your own is likely to be cheaper than paying someone else in the cloud.

If you do decide to run your own, don't pay top dollar for new home computer kit, go on Ebay and pick up used Dell servers (or similar) for next to nothing, with a second hand 19" rack - oh, and don't forget a decent UPS.

However, when costing Azure - don't pay per CPU, select the option where you pay per cycle (haven't got it in front of me at the moment, so I don't recall the actual terminology). That way, you will be paying hardly anything to begin with, until you start getting a load of users.

Out of curiosity: What will you be doing with your servers and what are your requirements? Or are speed and price the only ones?

Azure de-facto has: Redundant high-speed internet connection, a cooling system, redundant power, a PSU, ...

If you say "this little risk of downtime is not important" hosting yourself becomes incredible cheap: Once det up, they will remain working (of course depending on what you do). It does require planning (cooling, disks and disk setup) and you are likely not as flexible (in terms of "let's just spin up another VM") unless set up.

All in all, it depends on your requirements.
If you would mind to explain them, we can give better estimates.

I am currently running <1k / year for a small home server (including time and electricity), but I can't say if that overlaps with your requirements.

@sbiewald
We need the server to run specifically the following;
-- Multiple instances of SQL server 19 (min: 3)
-- 3 web apps (1 specifically for SignaR service)
-- An FTP server
-- A mail server
-- Hosted Redis

We need a server that can withstand atleast 100,000 concurrent connections. The major on the above list is the signalR service which eats a lot of CPU and bandwidths due to its realtime capabilities.

We were previously making use of Azure's D2ds v4 VM (2cores, 8GB ram, 75Gb temp storage) this cost us about $250 a month excluding disk space. For storage we actually opt for their blobStorage package which is fair enough for its price.

As load increased we had the option to include an additional server forming a server farm and then integrate load balancing but it was a bottle neck for us while maintaining keys and tokens for concurrent connections among the servers using Redis, so we recently upgraded to
D8ds v4 VM (8cores, 32GM ram, 300GB temp storage) which looks very promising but triples the price.
If we can have a setup a little bit above the D8ds v4 spec with storage inclusive that would be fair enough.

@GiddyNaya Thanks. That changes it a bit.
I would assume you would need equally powerful servers (compare specs and benchmarks).

I wouldn't consider this "home hosting" anymore.

What you certainly need is:
a) an acceptable internet connection (I assume 100k connections use more than 1 kbit/s, right?)
b) The machine you will be using will be a 'real' server usually for server racks (get one as well, aren't that expensive). They usually produce some amount of heat, so you will need appropriate cooling.

What I'm not yet sure about is storage... While full flash storage sounds nice, enterprise ssds are freaking expensive, and consumer ones are not built for permanent use (they overheat or slow down after some time).
I don't think redis is that much a problem, as it is an in memory db (so storage speed shouldn't matter that much).

The mail server shouldn't be too problematic either (how many mails do you send / receive per minute?), for the ftp server I hope that as well.

@sbiewald Thanks for the heads up
Yes, I'll agree the server response is also reliant on internet connection speed based on bandwidth irrespective of the spec.

The mailing is outbound only and emails are sent on an average of 50 per min (Mainly for notification subscribers).

The FTP is just for basic server access for file transfer and updates made by 2/3 admins with minimal access control.

The need for storage is not really worrisome as we could get cheap third-party service for the file hosting only.

Does a raspberry qualify as a server? :)

@netikras The 8GB RAM variant of Raspberry Pi 4 will work great as a server but too bad it can only serve just me and my cat. :)