How many kH/s do I need to just do new coin mining?

[j2ee]

Currently I only have a HD5770 which provides around 200 kH/s. I have another desktop with 430W that I can add a graphic card. I may build rig if it really worth it. So any suggestion? I will mainly focus on new coin mining, any potential good new coin that just appears in this forum.

[BrewCrewFan]

not with a low PSU like that. Plus factor in age of PSU ( yes they wear down too ) and brand. Your better off buying a new mid-top level 750 watt PSU and getting some cards then. I recomend a 270x while they are cheap. The 7850s , the right ones can be had too cheap. Right now your going to over pay for the 79XX and the 280x and 290x cards/

[xrturbs]

I'm running 3x cards. PC is overclocked i7 to 4.02ghz 16gig ram. When I had 1x 7950 it was pulling approx 450w from the wall. When I had 1x 7950 and 1x 7850 it was pulling 590-620 from wall, that was on a Corsair gs600 psu, ran fine.
But i had to add another PSU to run to gpu's after adding another 7950 its now pulling 760-820 from wall depending on gpu voltage and whether im using usb port charging phone etc.

So mining at 1.4 Mh/s with the 7850 as main card, only running that at intensity 15 so I can still use pc and the 7950's are slightly under clocked and lower voltage, cause middle summer in Northern Australia this thing is cooking me in my room, and I dont like em running over 80c, the outside cards run 77c the center card 85c   

[xrturbs]

Oh check here for card mining speeds - https://litecoin.info/Mining_Hardware_Comparison

[j2ee]

not with a low PSU like that. Plus factor in age of PSU ( yes they wear down too ) and brand. Your better off buying a new mid-top level 750 watt PSU and getting some cards then. I recomend a 270x while they are cheap. The 7850s , the right ones can be had too cheap. Right now your going to over pay for the 79XX and the 280x and 290x cards/

Thanks for sharing. All cards are still selling with normal price in my city.