Newbie here.  Any help appreciated.

Setting up my rig.  This worked yesterday for a 36 hour run

      - MSI Z170A Gaming M7
      - 1x Sapphire Nitro (no plus) 8G RX480  (rookie mistake slower memory)
      - 1x Asus Dual RX 480 8G
          BOTH GPUs mounted on mobo
      - windows 7 64bit
      - Claymore v 9.3
      - crimson v 17.4.3
      - firewall off


My config:

-epool USEast.Alpereum.ch:3002
-ewal (xxxxx)
-epsw x
-mode 1
-ethi 16
-tt 85
-asm 0
-wd 2
-benchmark
-fanmin 70

Ran great.  Just going for stability, not speed yet.  Both cards hashed around 24-25Mh/s

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Today the risers arrived. (MintCell v006)

Moved the the ASUS DUAL card to the riser.  Added a second ASUS DUAL card with riser.  Sapphire remained on mobo in PCIe slot.

Started Claymore.  All cards hashing about 24-25Mh/s

After 3 minutes of mining ATI driver crash.  One mining card stops mining.

Reboot.  Same behavior.

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Read the forums.  Tried to back off to the suggested v15.2 driver, but it would not run with my RX 480.  Settled on driver 16.11.5

Same behavior.

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Ran the rig with the Sapphire mounted in case and only 1 ASUS on riser.   This was stable.

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Any ideas?  I have swapped risers to no avail.  I can run 2 cards stable, but adding the third causes a crash a few minutes into mining.

At the time of the crashes no cards are running super hot.  (60-70 C)

Thanks