400w replacing radeon 4870 gpu

[woodygar]

Hi
Can someone advise me please. Looking to replace my video card its radeon 4870 for skyrim. I Know the recommended power supply is 500w for my old card but i never had a problem. I was looking to replace it with the 6870 or the 6850. According to a few review sites these new cards use less power than my old card.
radeon 4870
153 idle
283 load
radeon 6870
128 idle
247 load
radeon 6850
131 idle
251 load
Would i be right in thinking it would be ok to upgrade to the new cards and the 6870 actually more efficient than the 6850 card.
Thanks

[[GSV]Trig]

I had the 4870 Toxic thing and replaced it with a 6870.
Spec of my rig is <----

All ran off an Antec 430W PSU...

[woodygar]

cheers thanks

[Bagnaj97]

What make (and preferably model number) is your PSU? There's a big difference between decent makes and unknown brands. Cheapo PSUs often can't supply their rated power and have a high failure rate with a tendancy to take out other components when they go. If your PSU is decent then a 400w should be ok.

[[GSV]Trig]

Mines an Antec True Power 430