I have an old rig which is powered by RM1000 modular PSU and is running fine with 6 x Rx 570 cards.I use Sata cable to the risers as it depends on the PSU cables,with this PSU I never had problems but when first I was using 2 x Coolmaster Lite 750 Watt I got a lot of burnt sata cables and graphic cards freezing.Once I switched to Corsair all my trouble got away and it is the only brand I use for powering up my rigs.You will be fine with this PSU even when using sata connectors so nothing to worry about.