Just for reference for those wondering about ITX sized GPUS that will fit in an MI-6:
GTX 1070 has a 150 Watt TDP
GTX 1080 has a 180 Watt TDP
RTX 2070 has a 185 Watt TDP
RTX 2080 has a 225 Watt TDP
Navi 5700 has a 180 Watt TDP
Navi 5700XT has a 225 Watt TDP
Radeon VII has a 295 Watt TDP
RX 580 has a 185 Watt TDP
RX 590 has a 225 Watt TDP
Vega 56 has a 210 Watt TDP
Vega 64 has a 295 Watt TDP
Radeon R9 Nano has a 175 Watt TDP
Radeon R9 Fury X has a 285 Watt TDP (AIO Cooling)
With the exception of the water cooled R9 Fury X, we haven't really seen any 2 slot ITX side GPUs above 210 Watts. The 210 Watt unit was a Vega 56 Nano but most reviews indicated that at stock settings it was running a 100mhz slower core clock than most Vega 56s, which would probably lower the TDP into the range of 190 to 200. I may be wrong, but I don't recall seeing any RX580s or RX590s in mini form. I have an RX 570 mini from Sapphire and it runs quite warm and loud compared to my MSI Aero 1070.
Of the new generation of GPUs, I would expect to see the RTX 2060, RTX 2070, and possibly the Navi 5700 as ITX candidates. Perhaps we could see the Navi 5700XT and RTX 2080 if a combination of 3 slot vaporchamber coolers, faster and louder fans, and possibly AIO are used. I know EVGA has released a 1660TI 3 Slot mini cooler, but that's too big for the MI-6.
Anyone fit any 2 fan units in like the Zotac Mini 1080ti?
Essentially, you can have 2 of these 3 characteristics: Fast, Small, Quiet.