More than 7 GPU on a motherboard

Someone is able to put more than 7 gpu on a motherboard ? After 7 my rig don't boot.

I use pci splitter like this one :

http://www.ebay.ca/itm/PCI-e-Express-1X-to-3-Port-1X-Switch-Multiplier-HUB-Riser-Card-USB-Cable-1PC-/141865200790?hash=item2107d32c96:g:zTwAAOSwa-dWhMvm

Ubuntu 14.04
ASRock H97 Anniversary LGA 1150 Intel H97 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard
MSI Radeon R9 390

I try with ESXI but the VMware graphic card cause the same isue that if i put my primary graphic to CPU. This cause bug and problem.

Someone is able to use ESXI for mining ?

Thanks.