A bit off topic but I picked up a GTX 970 (Gigabyte Windforce 3x) only to realise the TDP of this card is not 145W but 250W. With stock BIOS, 100% power target and +160 Mhz core OC it draws 234 watts from the wall mining groestl (which seems to be the hungriest non-scrypt algo) on a 80+ gold PSU. It seems its efficiency plateaus around 40-60% power target limit depending on algo:
I have the same card and it draws 170 from the wall on Quark. I'm not sure why it would draw 250w, it's the same architecture, unless they boosted the core voltage (the vcore is the same as my other cards). Are you using a wall meter? I noticed there is a lot of headroom as far as the TDP on the cards, but they don't draw that much, at least mine don't.
It's an OC version, should have added (GV-N970WF3OC-4GD). The voltage is 1.212 and with +160 Mhz it boosts to 1476 Mhz.
I measued with a watt meter at the wall. Same card draws 242.97W in a stress test in this review:
http://www.tomshardware.com/reviews/nvidia-geforce-gtx-980-970-maxwell,3941-12.htmlSo from Gigabyte both the OC and Gaming editions have a factory increased max TDP of 250 watts. Not sure if that makes me happy though. I wonder what a 145w TDP 970 does but it seems most people have the 250W cards.