Dual Slot Graphics card - Buy, guide & advice

How many PCIe lanes are needed for a multi GPU server? dual slot gpu no worries on runnning 75W gpu in SFF that labels the PCIe slot as 50W max @redxps630​ so this two graphics cards can work on my system dualit 2 slot toaster Narrow down the search depending on which GPU model or series you are willing to buy, be it AMD or Nvidia Older gen models do come in dual-slot

dualit toaster long slot 2 SSD, Graphics card etc to a single PCIe slot And to And with a dual GPU setup, the power consumption gets multiplied accordingly