I'm planning my first PC build and want to confirm compatibility before buying anything. The main parts are a Ryzen 7 7800X3D, Thermalright AXP90-X47 CPU cooler, Gigabyte A620I AX Mini-ITX motherboard, 32GB of DDR5-6000 memory as two 16GB sticks, a 1TB Kingston NV3 SSD, an ASUS Dual OC GeForce RTX 5070 with 12GB VRAM, an NZXT H2 Flow Mini-ITX case, and a Corsair SF750 750W SFX power supply. I'm open to changing parts if there are better choices, especially since this is my first build.
4 Answers
Run the complete parts list through a compatibility checker. It can flag issues such as motherboard BIOS support, physical clearances, memory compatibility, and whether any extra updates or adapters are needed. It’s also worth checking the motherboard and case manuals directly before ordering.
The A620 board is a very budget-oriented choice for a 7800X3D. I’d consider a B650 or B850 Mini-ITX board instead if the price is reasonable, since you’ll generally get a stronger feature set and better upgrade support. Also make sure the exact board revision supports the processor without requiring an older BIOS.
An AMD graphics card could also be worth comparing, although the RTX 5070 may still be the better choice depending on the games, ray tracing, upscaling, and current prices you care about.
Mini-ITX builds are possible, but they’re much less forgiving for a first build. A micro-ATX case and motherboard would usually cost less, provide more room to work, and offer better airflow and upgrade flexibility. If you’re not specifically trying to keep the system tiny, micro-ATX would be the easier route.
The AXP90-X47 should physically fit in a compatible Mini-ITX setup, but it’s a small cooler for a 7800X3D. Gaming temperatures may be fine, but heavy workloads can push it into the higher temperature range. Check whether the case allows a standard 25 mm-thick fan, and consider using a less aggressive CPU power limit or a negative curve optimizer setting if temperatures and noise are high. Also confirm the graphics card length and thickness against the case clearance, since that’s one of the easiest places for a small build to run into trouble.

I already checked the list with a compatibility tool, but I wanted a second opinion before buying everything. Thanks!