@Micallen
Personally, I'd say you could probably get quite a bit of performance with the hardware you have at the moment. A full clean install of Windows with a clean install of drivers can be amazing for performance. Also there's lots of performance tweaks you can do with Solidworks, one of the biggest I'd say to check first if any add-ins are loading at startup, disable all except what you absolutely need. I won't go down the SWX tweaking rabbit hole, there's lots of resources out there that would do a better job than me.
The other thing is that Dell 3630 looks pretty cramped for airflow, I'm not 100% certain but the motherboard (MOBO) looks like it might be a standard size, I'd say get that thing into a case with better airflow or if possible, get a bigger cooler on your CPU, it's probably slowing down because it's getting too hot! I like to use OpenHardware Monitor, but there is other software out there for monitor system temps, if you're above 80° C regularly, I suspect you're losing performance from thermal throttling. At minimum, open it up and clean out the dust (don't let the fans spin at high speeds if you're using compressed air) and make sure all vents are clear, if you're comfortable with it, look up how to apply new thermal paste to the CPU cooler. Also, you mentioned the SSD is an M.2 drive, but you should see if you can find out if it is NVMe SSD or SATA, the former will be considerably faster. Finally, the Dell 3630 is listed as having a 300W power supply, I would definitely suggest getting something around the 500W range sa the 8700 may slow down if it starts to reach the power limit (which may be set by the Dell BIOS, meaning it won't matter anyhow).
The advice offered by others about something new is sound. Although I'll say that in general (recently) high CPU speed correlates with a higher number of cores, so even though 12 cores might not be useful (unless doing rendering or simulations), that processor will likely have a higher clock speed and/or IPC (both of which are better for CAD modeling). The Intel 8700 isn't a bad CPU, but the Intel 10 and 11 series processors are not bad on pricing right now and you'll see a performance bump. You'll definitely have to get a new MOBO and you can probably use your existing RAM, but you may want to consider something faster if you do go with a new CPU. The Ryzen 5000 series CPUs are also great, the 5800x would be the way to go price-to-performance-wise. Of course I would expect new processors soon from AMD and later this year from Intel, so pending how much of a rush you're in...
For graphics/video cards, the difficult thing is timing at the moment. Pricing and availability is
rough for graphics cards (GPUs) at the moment, although there has been a minor trending downward recently. Your existing card should be okay for a bit until pricing and availability (hopefully soon) settles down.
Not sure if Solidworks has a formal position on Windows 11, but I would steer clear of it for now, but it's a good idea if you do choose the upgrade route, to make sure whatever hardware you get will be compatible going forward. If you get something from an OEM (Dell, HP, etc.) or custom integrator (like Boxx, System76, Pudget Systems, etc.), make sure to stick with Win10 and to ask about compatibility with Win11 for the future.
Other hardware notes:
- NVMe SSD (storage) - Gen4 if you can afford it, but Gen3 isn't terrible; but be sure the motherboard supports Gen4 and the drive is NVMe M.2
- Power Supply - make sure to get something from a reputable manufacturer (personally I'd recommend Seasonic), poor power = power performance or worse (damage to other hardware), 500W is probably the minimum, 650-750W if you want to keep using it for other builds (they should last easily 10+ years)
- RAM - recent CPUs tend to perform better with higher speed RAM, if you work with a custom integrator, make sure to get their recommendation
- Cooling - personally I like air coolers, but lots of people get all-in-one (AIO) liquid coolers; don't skimp here as a warm CPU will not perform as well
Finally, price is always a big factor. What's your budget? How technically capable are you? Have you ever built a PC before or do you want to? If you go with a custom integrator, you're going to pay quite a bit for it. I spec'd a PC to build myself and compared it to Boxx for the same build minus a few differences in things they don't let you change; the price was double with Boxx! One nice thing is you get customer support (I can't speak to how good anyone's would be) and they might even do some performance tuning for you, so you get the most you can from your hardware.
If you want a to build a PC or if you want a list of parts to compare to, let me know. I've done a lot of configurations and can probably fire one off in under 20 minutes. If you decide to do some maintenance, let us know how it goes, or if you go the new route, please share what you got (I'm always interested to know what people are using)!