Thanks for all the detailed info. It makes recommendation much easier!
- Motherboard:
Your current motherboard is an ATX form factor. The only motherboards that are larger are EATX form factors. You need to check the specs of your case, but as a ‘full tower’ it’s likely that it can accept EATX motherboards. But make sure before you buy an EATX motherboard (which are rare these days.)
Your current motherboard is a decent design, but it has a fairly weak 10-phase VRM (Voltage Regulation Module) design. I think VRM is one of the most important aspects when choosing a new motherboard. My AORUS X670 Pro X has a 16+2+2 design, which is not ‘high end’ but it’s very good, and helps contribute to overall stability as load increases.
There are three main AM5 motherboard chipsets that are appropriate for 7xxx and 9xxx CPU’s. They are: X870, X670, B650 (and X870E, X670E.) The feature sets are more comprehensive in the X870E, less so in the non-E version, X670E, and even less in the B650. I bought an X670E (Gigabyte X670E AORUS Pro X because it has a good feature set without being outrageously expensive (some X870 boards can cost up to $1000, and frankly, I don’t need the extra features they offer.)
For a more budget build the B650 boards can be just fine. I think X670E is the sweet spot. Here’s a video that can help you decide which one to purchase. There are other videos like it for X870E and B650 boards.
- RAM:
DDR5-6000/CL30 is considered the ‘sweet spot’ for AM5 CPU’s. The reason is that the memory controller timings are negatively affected when you exceed DDR5-6400, and even 6400 can present some configuration challenges.
There are users here who have successfully configured DDR-8000 RAM, but that takes work, and it’s always a risk that you may end up with an unstable system if you don’t know what you’re doing. I went with DDR5-6400/CL32, and it was a painless install and my system has been very stable, with only a few tweaks. If you want the easiest and most reliable setup, get 64GB (2x32GB) DDR5-6000/CL30 RAM.
- Cooling
I started my journey 3+ years ago and decided to build a liquid-cooled system. At the time, my 5800XD was liquid-cooled, and my 3090 Ti was air-cooled. I soon found that the GPU was pumping a LOT of heat into my case, and even though I have a large case with lots of fans, I felt like a change was needed when I built my AM5 system last October.
I bought a water block for my GPU, and the system runs very nicely. The 9800X3D will run just fine on a quality air cooler. Your tower case should be plenty big enough (but you want to measure twice to be sure when deciding which cooler to get.) But of course an AIO CPU liquid cooler on a 360mm radiator would be a great choice as well.
The problem with liquid-cooling a GPU is cost and complexity. They make very few AIO (All In One) cooled GPU’s (I don’t know if anyone even makes a 4090 AIO model) so you’ll have to invest in a water block and a custom loop (reservoir, pump tubing, fittings, radiator) and that can drive the cost up. To me it was worth it. In fact, it was kind of fun!
Modern 3-fan 4090’s will stay cool in their stock configuration, but that heat has to go somewhere - which is inside the case. Make sure you have plenty of fans in that case. If you don’t, you may want to invest in a new one. I’m very happy with my Corsair 5000X RGB. The 5000D Airflow is excellent as well. I’ve only had one complaint, and that’s when one of the ‘tempered’ glass side panels shattered as I was handling it. Corsair admitted that they’d had a defective lot of glass panels, and sent me a new one. Cleanup was a pain, but stuff happens, right?
- One last thing:
When I built my new system I installed a clean copy of Windows 11 Pro. I was a bit unsure about following the instructions in this video, but so far, having a debloated Windows install has been a great decision.
Best of luck. We have lots of knowledgeable folks here who are happy to help guide you. Don’t be afraid to ask for help as you continue your journey from AM4 to AM5.