Beware: Most cases are bad, cook your components to a crisp and will cause crashing.
Don’t consider cases that don’t have an open mesh front panel.
If it looks thermally constrained, it is.
If you’re stuck with a thermally constrained case like almost any NZXT, I can modify your front panel and get your thermals in check, just submit a ticket or text.
The Phanteks P300A is an excellent choice for around $50
The Corsair 4000D High Airflow is an excellent choice for around $70
Inadequate CPU Cooler
Gone are the days that the included heatsink is adequate. Don’t even plan to use it.
Don’t consider CPU air coolers. Due to increasingly hot neighboring components, even the best ones struggle and heat soak the rest of your components.
Budget $100-$150 for a good AIO.
An excellent value is the Arctic Liquid Freezer series.
An excellent value with RGB is the Corsair Capellix series.
Inadequate Case Fans
Included case fan(s) are not sufficient for gaming rigs.
Beware: RGB fans average about 50% or less airflow than their non-RGB versions, and should be avoided entirely.
The only high performance RGB fans on the market are the ones that come included on the Corsair RGB AIOs and NZXT AER RGB 2 fans.
The NZXT are black-bladed and the RGB effect is a little dull whereas corsair are frosted so the RGB effect looks a lot cooler when the fan is lit up. I would only get NZXT if you have a Kraken AIO.
Budget $80-100 for intake and exhaust fans, or $40-50 for exhaust fans if buying an AIO, as that will serve for your intake fans, reducing your fan budget.
The Corsair ML Pro series are an excellent choice, with 75CFM on the 120MM version and nearly 100CFM on the 140MM version, and magnetic levitation bearing tech.
Avoid the ML PRO RGB variants as they have only half the airflow.
Improperly Wired GPU
Your power supply includes at least two PCIE power cables.
Use one entire cable for each power connector on your GPU.
Do not use the pigtail connector on each PCIE power cable.
Improperly Installed M.2 SSD
Your motherboard includes the standoffs and screws needed to fasten your M.2 style SSD(s) to the board in the original box. The standoffs and/or screws usually do not come affixed to the board.
Don’t remove the SSD stand-off and use it as a way to fasten it to the board. This is the #1 mistake I’ve seen this past year and can cause the board, SSD, or both to short out.
The SSD must also have a heatsink attached! If your board didn’t include one then buy one.
(4) Do NOT use the pigtail connector on PCI-E power connections.(5) Do NOT install nVMe SSD with the standoff above the SSD as pictured. It’s supposed to be screwed into the standoff, not the standoff used as a screw.