v8 -> v9 power consumption jump 
~35%
~35%How did you measure it?
What cards do you use?
I see much less jump, may be 5-10%.
Power consumption from wall.
I measured it on one of my rig, not new (old):
- CPU: core2duo
- Mem: DDR2 2Gb
- PSU: Enermax 550W (old, even not bronze)
- VGA: 2*XFX280X GPU/MEM:1030/1500 VCDD:1v
miner setting GPU 0/1: -ss 1/2 -t default/8
Miner v2.0 375w
Miner v2.1 380w
Miner v3.0 405w
Miner v3.1b 410w
Miner v4.0 405w
Miner v5.0 400w
Miner v6.0 395w
I measured it on one of my rig, not new (old):
- CPU: core2duo
- Mem: DDR2 2Gb
- PSU: Enermax 550W (old, even not bronze)
- VGA: 2*XFX280X GPU/MEM:1030/1500 VCDD:1v
miner setting GPU 0/1: -ss 1/2 -t default/8
Miner v2.0 375w
Miner v2.1 380w
Miner v3.0 405w
Miner v3.1b 410w
Miner v4.0 405w
Miner v5.0 400w
Miner v6.0 395w
I don't remember v7 and v8 power consumption
but I did last measurement
v9.1 460
That's getting a little high for wattage for the v9.1. Maybe try to underclock the memory and it shouldn't affect the cpd as long as the core clock isn't changed.