Hi All.

I would like to ask a question about Z400, I have two rigs based on the z400, the first one is a 3x1070 the second one is a 3x1060. I've started with 3 gpu's per rig because just 3 pci-e slots are gen2. Now I want to use the 4th pci-e slot whch is a gen1 pci-e, but I'm getting problems.

The tow rigs on a setup of 3xgpus were mining rock solid for 1 month. Now I've tested to add a 4th card on the 1070gtx rig, the rig crashes after 2-3 hours of mining activity, I've reinstalled nvidia drivers and almost all the software, tested with different miners, and I'm always getting the same problem.

At the beginning of my build I get problems also when I was using the gen1 pci-e so I would like to ask for help because with all the profits going down I want to increase density on this two rigs, so any one found this problems in Z400 workstations and have you found a solution?. Or maybe is better to buy a 4x or 2x pcie multiplier to connect 2 gpu's on every pci-e gen2 slot?

The psu is a 900w modular psu, with enough cabling to wire the gpus and the risers, so I've discard also a problem with the psu. Any help will be appreciated.

Thanks in advance.