if you are not planning to go beyond 4 cards i'd stick with epixoip's recommendation and have a look at CHENBRO RM41300-FS81.
i wanted to go beyond 4 cards, so CHENBRO wasn't an option. A good choice for up to 8 cards would be TYAN FT77. it's good but it's expensive. Therefore i did a hacky custom setup: https://anonimag.es/image/mur ... it's using an industrial pc chassis, a cheap i3 consumer board, low profile pcie risers, a 2000W power supply and currently stacked with 5 GPUs. two good fans in the back are keeping things cool enough.
honestly, was a real PITA building it ... even though i'm happy now. took me several attempts and lots of hardware "research" to get everything right in the end. therefore i can't recommend doing it the way i did, too much troubles to solve. so either stick with something suitable for 4 or less cards, like chenbro, or take a load of money and get something like FT77. ;-)
p.s. i really like this "open" custom setup, too: https://hashcat.net/misc/d05.jpg
i wanted to go beyond 4 cards, so CHENBRO wasn't an option. A good choice for up to 8 cards would be TYAN FT77. it's good but it's expensive. Therefore i did a hacky custom setup: https://anonimag.es/image/mur ... it's using an industrial pc chassis, a cheap i3 consumer board, low profile pcie risers, a 2000W power supply and currently stacked with 5 GPUs. two good fans in the back are keeping things cool enough.
honestly, was a real PITA building it ... even though i'm happy now. took me several attempts and lots of hardware "research" to get everything right in the end. therefore i can't recommend doing it the way i did, too much troubles to solve. so either stick with something suitable for 4 or less cards, like chenbro, or take a load of money and get something like FT77. ;-)
p.s. i really like this "open" custom setup, too: https://hashcat.net/misc/d05.jpg