PCI-e risers

Hi! I'm building a new rig for oclhashcat and I was wondering if I could save up on the motherboard, and get one with only 2 16x PCI-E connectors, and 2 1x PCI-E, and use 1x to 1x powered risers to plug 2 cards into the 1x slot. I know that for mining the bandwidth bonus of 16x isn't important, but am I going to see performance degradation with hashcat?
Yeah I know I should buy proper hardware but I'm on a tight budget!