Help me choosing ram please

zaragan · September 19, 2020

Hi everyone, one of my ram sticks died yesterday and with only 1 stick more i need help to decide from the support list of rams for the x399. I'm don't know much about rams that's the reason im here. I need 32 gb divided by 2 or 4 sticks with a budget of 300€ (amazon or european website please).

My actual config is this

Mobo: x399 sli plus

Proc: Ryzen Threadripper 1900x (1st gen)

Also, if someone can answer me a few questions i have about ram slots i'll apreciate it!

I understand the slot channel configuration, but i dont understand if i can have 2 different rams on different slots so i can use the last stick i have. (one on the 1 or 3 channel and others on the 2-4 channel) (also, this mobo have 8 slots, i supouse it supports quad channel? It's that a thing or it splits the 4 sticks on 2 duals?)
I've seen that when choosing ram you need to look and match the ram freq to the core speeds of the proccesor, why? It matters?
How i can check if a ram is "bad"? Because i've been playing with the placement and the number of the rams and i think i have 2 sticks bad and i doubt for the 3rd, because the rig works awesome with just 1 stick and when i install another stick the performance of games and browser decays by A LOT (90-150 fps with one to 30 fps with 2. When i start the game with 2 sticks it starts good (100fps but it decays over time reaching 30fps by just playing 30 mins).
I've seen videos where the cpu core speed and the DRAM freq almost doesn't move but in my case it fluctuates a lot, why?