It really depends on a lot of things, primarily what you were doing before the system went EOL vs what you want to keep doing with it.
With no change in operation, everything is good. If you're squeezing clockspeed or memory, that could be good but some things may break.
If you change the roles, it can get real shaky. As an
overclocker first, I've had a few gaming computers and this has been the experience.
Changing CPUs is usually okay. Changing memory for size is okay, for overclocking it's a coinflip. Adding new hardware is anyone's guess.
Pentium 4 3.00E with 512MB and Radeon 9200 -> 2GB and a AH3450, general Non-DOS gaming and very early Minecraft capable.
When I racked this, it became a gaming server and my fans LOVED it. Low latency high population (48人) community fragfest heaven.
Phenom II X4 955 with 4GB and HD3300 IGP -> 8GB and a HD6570, unlocked video editing, 3D modeling and early Unity VR support.
When I racked this it didn't last very long. It underlined issues that were happening with prior storage and the onboard IGP.
Garbage.
FX-8370 with 16GB...I'm at a crossroads with this one right now and it's the closest compare that I have to the 4790K. How's that? Well...
Close enough. Not a bad performer but not great either. One pattern you'll notice is these are all retired gaming computers.
I obsoleted the FX box with the R5 3600 and RX580 for general desktop. I've been on a gaming hiatus for a while.
Functionally, FX is a workhorse. I can toss my RX580 in there for support but it's just random JBOD management.
The chassis is a very generic 2U that holds a bunch of disks that are basically just there to exist (for now).
It deserves to be useful for the future by turning it into a video rack so I'm collecting information on some cards.
AVerMedia, Blackmagic, NZXT capture cards...Radeon Pro WX2100/3100 or Quadro P400 for display out/NVENC.
Basically a dedicated rec/stream. It's capable and has the PCI-E lanes to spare. The CPU is already the best pick.
Memory is another issue. I've gone through a few boards that don't like more than single DIMM per channel.
Intel boards of that era don't typically respond very well to high speed memory but I can run 16GB 2133 all day.
It may be possible to double up to 32GB but no idea if it makes the FX memory controller or mainboard screech.
You most likely won't have that issue but if you're looking at doing anything where you need the extra memory, do it.
I main a DDR2 box for my main storage server and the good kits are GONE gone. DDR3 is still in a discount sweet spot.
That window will probably close by the end of this year since DDR4 memory has gotten much cheaper as of late.
As for anything you plan on slotting into your board, start counting lanes, specifically the ones that can be used.
You'll figure things out very quickly.