PCIe 2.1 GPU, PCIe 1.x mobo: Potential pitfalls?

Howdy folks,

So finally, it's RIP to the 9800GTX... See my other thread for the sad story.

http://www.tomshardware.com/forum/forum2.php?config=tomshardwareus.inc&cat=33&post=333613&page=1&p=1&sondage=0&owntopic=1&trash=&trash_post=&print=0&numreponse=0&quote_only=0&new=0&nojs=0#t2491449

I've lined up the MSI Radeon HD 6850 Cyclone Power Edition/OC -1GB as a potential replacement. A few things concern me though:

1) Putting a PCIe 2.1 card in a 1.x slot seems to be something of an unknown quantity; works for some, not so well for others. Any advice in this regard would be appreciated.

2) Power is another question mark. From what I understand, PCIe 2 delivers more watts that PCIe 1 did. Hence I'm slighty worried that the slot + one 6pin connector will not be enough to power a 6850. The card only has one power connector, so I can't add a second one for a safety margin.

If the 6850 will not work, I'm open to other suggestions. Systems specs are in my sig.

P.S. StarCraft 2 is the most graphically intense game I own, and that's not likely to change soon.
 
I believe they are the same electrically all supplying 75watts "Power
PCI Express cards are allowed a maximum power consumption of 25W (×1: 10W for power-up). Low profile cards are limited to 10W (×16 to 25W). PCI Express Graphics (PEG) cards may increase power (from slot) to 75W after configuration (3.3V/3A + 12V/5.5A).[8] Optional connectors add 75W (6-pin) or 150W (8-pin) power for up to 300W total."
 
a good clue is to search your motherboard model + a newer gfx card in google. If any forum results show that it doesn;t work, then I would be wary. the board I used to have, search this http://www.google.com.au/search?source=ig&hl=en&rlz=&=&q=Asus+M2NPV-VM++6850&oq=Asus+M2NPV-VM++6850&aq=f&aqi=&aql=&gs_sm=e&gs_upl=1036l2140l0l2408l6l6l0l0l0l0l344l617l1.0.1.1l3l0#sclient=psy-ab&hl=en&source=hp&q=Asus+p5n-e++5850&pbx=1&oq=Asus+p5n-e++5850&aq=f&aqi=&aql=&gs_sm=e&gs_upl=82194l83546l2l84497l5l5l0l0l0l2l351l1478l2-3.2l5l0&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=403a1c33a064236&biw=1920&bih=985 and it comes up with many problems. Searched for your motherboard and a bunch of different vid cards and couldn't find any issues.If you like SCII I believe you will be slightly better off with a nvidia card, like the gtx460.
 
OK, I tried out a borrowed 6850 and it worked, although the performance was not fantastic. In 3DMark06 it benched about 16% better than the 9800GTX. The card was running extremely hot though, which was unexpected.
 
HD6850 installed and purring like a kitten... Yeah! I haven't put it through its paces properly, but so far I haven't been able to push the card beyond 62C. The Cyclone cooler is amazing...