Всем привет.

I would like to ask a question about modification of any AMD RX 5xx from 4GB to 8GB.
Are there any favorites? I don't have experience which models of which manufacturers can be modified to 8GB?
Do you have any practice and what to avoid?

there are no favorites. re-soldering the memory and flashing the BIOS

Do you mean that all 470...590 can be modified to 8GB without any exceptions?

The context of this modification assumes, that the card(s) will be used in mining :) Considering that I would suggest my own favorite, Sapphire. One of the best cooling systems (all memory banks are in contact with heatsink; easy swappable coolers, compatible within the most 4xx/5xx models; easy to clean the heatsink without dismounting it from GPU), power system have fuses, and the main advantage for the subject - there were a huge amount of models, so it's pretty easy to find a working bios.
Avoid ASUS Dual series. Shitty cooling.

Yes I have some dead ASUS Dual series with dead GPU. Yes people ask for making 8GB from 4GB versions for mining due to the shortage of cards. I simply didn't do it previously.
What memories to use? The same type as they were inside but bigger? I have around 1000 Samsungs for a very cheap price. What do you advice from your practice?

Yep, that's just 8 x 1 GB memory banks instead of 8 x 512 MB, nothing more. Samsung are the best for mining, as they're the most stable and overclockable. Micron are also good, but less overclockable. Hynix is the least performant. But in general, GDDR5 were all pretty durable, that's not early Micron GDDR6. Easy to reball, easy to solder, that's a gold mine right now, if you have an access to some memory chips :D

Смотрите какие есть модификации биос и с какой памятью под эту карту. The best of green.