Does anybody run 5 or 6 x Vega 56? is it true the maximum is only 4?
I manage 2 mining rigs, with 5 Vega 56's on each of them. Mining with Xmr-Stak-Amd runs smoothly and very stable. According to the pool the average hashing power in the past 24 hours of 1 rig was 9,65 KH and the other 9,62 KH. According to Xmr-Stak-Amd the hashing rate is somehow lower at 8.9-9.0 kh for each mining rig.
They both have the same settings mentioned in this thread (gpu @ -30, memory at 950, fanspeed at 3500, powerlimit at -20% total power consumption of ~970 watt per rig, hbbc at maximum and virtual memory @ 64 gb.) I haven't changed the voltage.
Both mining rigs have only 8 gb ddr4. The HBBC-slider is visible, but only allows to increase the HBBC-memory from 11600 to 11773 mb. On 1 of the 2 mining rigs, i can't adjust the HBBC-slider for the 5th gpu. The other 4 gpu's are adjustable. On the other mining rig all 5 gpu's seem to be able to get the hbbc-slider adjusted, although Wattman might give a false impression, i don't know, and i don't think this gives a significant boost. With 16 gb of ram you can increase the HBBC-memory to 14000-15000. I have ordered additional ram, which should arrive this week.
I would also like to mention that I didn't had to use a hdmi-dongle or something like that to get 9,62-9,65kh. After closing the monitor, the hashing rate doesn't seem affected.