I built this Mini-ITX PC in fall 2015 and haven't followed hardware closely since. It still performs perfectly well for my needs, but I'm wondering whether its age means I should replace it before something fails unexpectedly. I'm in Canada and would prefer to keep the current case. I already have a monitor, operating system, keyboard, and mouse. I mostly browse the web, watch YouTube, and code in a terminal. The most demanding games I play are Halo: The Master Chief Collection, Fallout 3, the original Mass Effect 2, and Oblivion, and I don't expect to start playing newer or more demanding games. The operating system is on a 120GB SSD from 2015, while my data is on a newer 1TB SSD. The original CPU cooler and graphics card have already been replaced. Current parts are an Intel i5-4590, ASRock H81M-ITX motherboard, 8GB of DDR3-1600 memory, GTX 1650 SUPER, Noctua NH-L9i cooler, Cooler Master Elite 130 case, and EVGA SuperNOVA 650 G1 power supply. Should I keep using it, make a small upgrade, or build a replacement now?
3 Answers
The bigger issue may eventually be software support rather than performance. This fourth-generation Intel platform isn't officially supported by newer versions of Windows, so moving to Linux could extend its useful life if you're comfortable with that. For gaming on Linux, AMD graphics cards are generally the simpler choice, but there's no need to change anything while your current setup remains satisfactory.
I would keep the current computer going and save for a future build. Component prices make an unnecessary upgrade harder to justify, and your stated workload doesn't benefit much from a new CPU or graphics card. If the old SSD is important, make sure you have current backups and consider replacing it if its health starts to decline.
If it already does everything you need, there is no compelling reason to replace the whole system. For your games and everyday use, the CPU and graphics card are still adequate. The one inexpensive upgrade worth considering is adding another matching 8GB DDR3 stick so the system has 16GB and dual-channel memory.

That seems like the best low-cost improvement. DDR3 is still fairly easy to find, and it avoids spending money on a new platform before you actually need one.