I didn't see all your post but did you install windows in uefi mode?

https://blogs.technet.microsoft.com/home_is_where_i_lay_my_head/2012/10/02/how-to-check-in-windows-if-you-are-using-uefi/

Nice work!

6x 1070 GTX each at 29MH/s no dual settings.
I get the same hashrate as with claymore. @+400Mem, 85% tdp.

My only issue is that it takes a few min to reach this speed and I fear that nicehash benchmark won't run long enough to use the top speed for the profit calculation 

above 4g decoding in bios activated?
OS installed in uefi?

Linux or Windows?

Anyway 4 Gpu should work at least.

For 5 or more make sure Above 4G is enabled in bios and that you installed your OS in uefi mode.

Better check that first and if you did and it still doesn't work maybe bad riser, issue with motherboard, ...

Windows installed in uefi mode?

That did the tricks for me.

From what I gathered so far you need :

- Above 4G decoding activated in bios
- latest motherboard driver version
- Windows installed in uefi (https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/windows-setup-installing-using-the-mbr-or-gpt-partition-style)

I'll try that tomorrow on my conf

Hmm that's weird, 1200w should be enough. At least when I look at my psu thanks to corsair link it's never at full power but maybe yours pump more power I don't know.

Regarding my install I think I messed up my windows install because I saw in another post that activating 4G decoding require windows in uefi and mine is in Bios Legacy.

If someone can confirm?

Hmm chipset seems to be working for other but anyway I tried a new motherboard (msi z270a pro) and same shit!

I can make it work fine with 4 GPU without enabling 4G on bios.

But whenever I enable the 4G to put a 5 GPU my system freeze after 2 min.
And even if I only use 4GPU out the 5 connected.

I tried to find a potential bad riser but since it freeze when I have more than 4 gpu connected I'm not sure the issue is there.


So to summarize :
4 GPU mining, 4 GPU Connected = OK
4 GPU mining, 5 GPU Connected = NOT OK
1 or more GPU mining, 5 or 6 GPU Connected = NOT OK

I refuse to believe I'm the only one to have face this issue 

I changed another parameter in bios : PCI-e addressing to 64 bit and was able to have a 5th GPU running.

So now 5 GPU works but 6 doesn't lmao..
Worst part is that 6GPU works for like 2min before crashing WTF.
It either works or it doesn't but no middle ground.

I know that not all motherboard can handle 6 but I want to believe this one can 

Hello,

First time poster long time lurker.

I have been mining for some time now with my pc using 2 gpu and everything worked fine so I decided to invest a bit and buy 4 other gpu as well as multiple riser (oh boy was I wrong to fix it would be a smooth upgrade)

Update + Configure bios ... OK
Install GPU + Riser ... OK
Install Windows 10 ... OK

6 GPU are shown and usable with the miner I choose (Claymore or EWBF) but if I use 5 or 6 GPU after 2 min the system reboot (ONLY WHEN USING MINER)
If I use 4 GPU or less EVERYTHING works fine.

My Conf :
MSI z170a sli plus
6x PNY GTX 1070 OC xlr8
Pentium G4400
SSD 120Go Sandisk
ax1200i corsair
6x riser pcie 1x to 16x


What I tried so far :
- Drivers update (368.81 or 382.53)
- Bios Update
- Changing BIOS Conf (PCI-E gen 1, 2 or 3), Enabling 4G on BIOS, Settings Windows 10 conf in Bios
- Changing outlet for Power Supply
- Changing bad riser (all ok now)
- Changing virtual memory
- Putting each GPU on a separate PSU cable
- Putting max 2 riser per PSU cable

But nothing works 

Can anyone smarter than me gives me some input?