Hey guys, just pulled some old cards off the shelf to start mining again (280x and a 7970). Mined plenty of coins in the past but never ZEC and am running into some issues...

Setup:
Mobo - Asus M5A78L-M LX PLUS
OS - Win7 64
PSU - EVGA 700w Bronze
Miner Version: 12.0, 12.4
Driver: 15.12

The 280x (Sapphire DualX) is detected and hashing at around 240 using 12.4 and 180 using 12.0, but the average seems to be around 290 so I'm wondering how to increase these speeds a bit. Stock clock speeds and BIOS. Also, the 7970 (IceQ) is not being detected at all. Tried reinstalling the drivers and switching PCI-E ports and risers, still no luck. Virtual memory is set at 16gb. I've never had to use the "jumper trick" on this motherboard, but I was also mining on Linux previously - would that make a difference?

Running at intensity 5, are there any other config settings I can change that would help? Any assistance is greatly appreciated!

EDIT: I'm a dummy, the USB port on the riser wasn't plugged in all the way and the 7970 is working now. The hash rate increased a bit with the second card in (250 H/s per card) but is still about 40 H/s slower than other people with stock clock/BIOS settings.

Also, what utilities are people using to undervolt these older cards? Is it a desktop app, the BIOS, or can this only be done by reflashing the card itself? Thanks again!