Do you recall what you changed?  Did you just swap cards in random slots until it worked? Were you installing drivers? And did you get 5 or 6 working?

After spending far too much of my life on this I found this thread.  So I decided to post my story.

I have an asrock ab350 gaming k4. I have a mixed rig. I had 4 1060s and 2 580s to put me under my 1000w psu.

I originally bought two of these rigs.  My first had no problem with 5 gpu and is still running 5.

The second rig I fought with.  And fought.  And fought.  It was 3 months ago so I don't recall the details but I believe  I was able to get 6 cards running by installing drivers one by one and mucking with slots. After it was running it was totally stable and never did the black screen booting windows ->recovery. .  

Last week a fan died in the second rig and I swapped a 1060 with another 1060.  Nothing else changed and now the machine will not get to windows with more than 4 cards. I had forgotten about the initial pain of setup and now I'm pretty pissed.  

However, I did have  a m2 to pcie card laying around. So props to the previous post about trying that. I originally stuck it in m2_2 -and windows didn't see the card.  So I tried m2_1 and moved one gpu out of pcie 4. Now I have 5 cards running.

Later, I might try to get the 6th working.  I'm thinking if I boot to safe mode and install the drivers for 6th I might be able to get it going.  

Being excited about 5 cards working, I tried connecting the 6th and going to safe mode to install drivers.

All 6 cards are shown in safe mode with no cards needing drivers.  Yet booting windows normally fails.  

Not even sure what to try now.

Being excited about 5 cards working, I tried connecting the 6th and going to safe mode to install drivers.

All 6 cards are shown in safe mode with no cards needing drivers.  Yet booting windows normally fails. 

Not even sure what to try now.

Ok, I'll admit that I thought you guys were crazy when you first brought this subject up but today I set my cell phone next to one of my rigs while I was working in the area.  After a while I picked it  up to check it and it was registering no service.  Didn't give it much thought and rebooted it just to make sure it wasn't messed up (it's an older android).  Later in the day I set it back down again in the same spot and a couple hours later I grabbed it and once again no service.

So there is something to the interference claim.  However, I don't think it is Claymore's problem.   He may have contributed to it by pushing the cards harder but, hey, isn't that what we want anyway?  If I were to guess I would imagine that the interference is from the cards being pushed hard and the fact that most of us are running open air chassis, there is no metal 'faraday cage' to shield the interference from being a problem like there would be if the GPU was in a normal computer case.

wow, if this is the answer, I'll be so happy.  I am using windows 10 and a usb wifi chip.  I'll get a small hub and see if I can put the wifi card further away.  Last night when I tried the usb wifi was sitting right under the GPUs.  I was suspicious of interference, but didn't think too hard about it. 

Has anyone experienced claymore destroying your wifi connection? 

Without claymore running I can ping my gateway all <50ms.  As soon as claymore starts mining the connection seems to be wrecked. Pings drop and claymore cannot access the network. Some pings get through but very few and with huge delays (3000 ms).

The only solution I've seen people talk about is hardwiring.  I've noticed it only happens with my new router and my rig on the old router works.  However I cannot reach the old router from where I want the new rig.

nVidias are good for mining lbry (LBC), Equihash (ZEC, ZCL) and Lyra2REv2 (MONA) coins. I'm minig lbry right now.

Easiest way is to use nicehash, no need to care anything, just put in your BTC address and run it. They will mine most profitable coins and convert them to BTC.
If you want to play around you can use claymore Zcash miner or EWBF's CUDA Zcash miner to mine equihash coins and ccminer to mine Lyra2REv2 & lbry coins.

I have good experience using win10 and latest drivers (usually there are instruction from miner developer which drivers are best to use).
Can't tell you exact hashrates but you can expect something around 300 sols for Equihash, 180Mhs for lbry and 20 Mhs for Lyra ... use nicehashminer benchmark to get exact numbers.

also check https://whattomine.com/ to find the most profitable coin

I just bought two of the MSI 580 Gaming X and one plus version. 

On the non-plus - stock they ran about 22mhs.  I modded and got 25mhs. 

For some reason ANY modification to the memory clock COMPLETELY DESTROYS mhs.  At 2000 I get 25 mhs, bump to 2050 and it falls to 18mhs.  Slowly ramping up I might get up to 20 mhs until 2100+ will crash the card. 

I have no idea wtf is wrong.  I tried both MSI afterburner and wattman.  I tried oc the memory with no other adjustments and as soon as I touch the memory clock, mhs falls like a rock.  This happened with stock and modded bios. 

If anyone has any ideas, please give me one.  Oh - and I have hynix memory

I haven't tried modding the plus version yet.  It runs 24.5mhs stock, but temps are insane.  Like 85c already.