This mobo is very tricky. Do some tetris plug in plug out, try different combinations. Also is very important to have the latest BIOS, to have 4G enabled and have PCH, PCIe and PCI Express 16 slot to be put in GEN2. Just these three settings.

I already had 4 Rosewill Lightning 1300s.  On my two most recent rigs, I used hellae's recommended EVGA 1300W supernova Gold PSU.  (IMHO, these are overkill, but likely quite efficient.)

So I completed the tent project for the 24 Vegas.

https://imgur.com/a/RdnGr

Here's where to buy the tent:
https://www.amazon.com/gp/product/B00SUEHYJ8/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Here's the 8" duct fan to carry away the hot air:
https://www.amazon.com/gp/product/B00CAHM75W/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Here's the 4" duct fan to carry the heat to a room (for cold winters) above where the tent is located:
https://www.amazon.com/gp/product/B01M7S46YZ/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

I also use 2 8" personal fans to blow in cold air at ground level into the tent.

The tent is in a basement.  I had to bust through the brick and install an outdoor register vent.  Mine is just above the basement doors.  I connected about 10 feet of 8" insulated flex duct to that and into the tent.  I bypassed an existing 6" flex duct and routed it to the tent, stepped it down to 4", to heat the room above if needed.  The fan for that duct is controlled by the web power switch outlet.  The 8" fan runs continuously to the outside.

Inside the tent, which has plenty of room for more rigs if this experiment works, is a simple 4 shelf wire shelving unit.  Six open air wood frame rigs fit nicely on them.  I suppose one could just build their rigs directly on the racks.  The ethernet switch, web power switch, and monitor (when needed) fit on the top shelf.  I access these headless rigs with TightVNC.  I had previously run 3 separate, dedicated, 20 amp circuits to this room. 2 rigs (4 GPUs) per circuit.  (Having said that I doubt that I will run more circuits down to this area of the basement to fully utilize the size of this tent.  I have a little buyer's remorse and now recognize that I could have gotten away with a tent about half this size.)

The Vegas are stock 56s and using XMR-Stak as described here:
https://www.reddit.com/r/MoneroMining/comments/74hjqn/monero_and_vega_the_definitive_guide/
I use the DevCon batch file to initialize the miners. They average 1800 h/s/GPU.  The GPU fans are set to keep the GPU at 70F with OverdriveNtool. (I may BIOS mod and registry hack later.)  Just concerned with heat dissipation currently.

Now for the heat details:  I approached this problem as if the temperature inside the tent would be analogous to the temperature inside a gamer's computer case.  Most sources I found stated that those temps could easily be in the 50C range.  So I knew I had to beat that to protect the hardware.  Sapphire tech support got back with me and stated that the maximum acceptable operating temp for the Vega 56 was 92C. WOW!  The average temperature of the basement is 64F now and never higher than 70F in the summer.  I utilized the motherboard's temperature sensor as well as an independent simple outdoor thermometer dangling from the top support inside the tent.  Without the 4" fan in use, the tent got up to 112 F (44C).  That was good, so I used some other ideas to see if it could be improved.  I placed four 20" box fans behind the rigs.  As was previously stated in this thread, it hurt the cause, it did not help.  Unlike when in use behind double dissipation GPUs, the blowers on the Vegas already direct the exhaust "forward." So the box fans remain, but are turned off.  With the 4" fan in use, I got the temperature down to 102F (39C).

I hope this helps anyone who is contemplating going about trying this tent concept.

Hi Guys,

I have an issue with 4 x 56 cards flashed with 64 bios.

I have the HBCC settings only on 1 cards, so when i mine with 1 cards it's working, when i try to 4 cards nothing happend.

When i try to disable crossifre the system crash and reboot.

Any help regarding this issue ?

Thx

Yes, very stable
AMD drivers 17.11.1

link


Under the link Russian-language resource with settings and so on.

If you have your cards overclocked, have you tried dropping the clocks a bit ?