Do not buy any old ones.
buy amd
5500 8gb
5600 6gb. weakest choice due to 6gb but if you get it cheap buy it.
5700 8gb
6800 xt 16gb
6900 xt 16gb overkill
with or with out the xt
buy
nvidia
3060ti 8gb
3070. 8gb
3080. 10gb
3090. 24gb over kill
I would buy any of the above if I can get them cheaply
these are my least favorite to buy.
the amd 6900 xt
the nvidia 3090
but If I can get any of the above at proper pricing I would buy 2-3k worth
hi thank you for your reply
First question is this site show correct profit about gpu for now :
https://minerstat.comfor example its show about $4.15 DAILY for this model rx 6900 xt so is this site show correct ?
another question for example if my motherboard have few slot sold then can i use mix gpu model from difference brand ?
for example use RX 580 with 6800 xt and 3070 on one motherboard ?is this work whiteout any problem for mining on windows ?
You can mix teams of gpus (Amd/nvidia). It does complicate things a bit more but it works. I mix them in linux on several rigs with no issues. I think you want to put the nvidia card in the first gpu slot for some reason but just the way i do it...im sure somebody else does it other ways.
The 6900 is a bad choice because it has a low return vs its high cost. Same for 3090. They are nice cards but just too expensive vs other cards....although all cards are crazy price right now most places. A 3060ti or 5700XT are better choices...as the 3070/3080 and 6800 cards.
Both Minerstat and whattomine.com are fine calculators. Its a moving target and its only an estimate.