Physically the GA-990FXA-UD5 appears to use the same PCB and overall design in rev 1.x to 3.x . If it ain't broke don't fix it approach has served this as well as the GA-990FXA-UD3 well since the launch of Bulldozer. I'm sure some minor upgrades were made in some of the component selection over the years, maybe even better yields for the AMD 990FX Chipset itself. Taking a quick look at the specs and picture it would seem that nothing has changed in Rev 3.0 to 3.1
Good board, Good for overclocking those FX 8320/8350 s