How many watts PSU do I need for this setup?

[c789]

The small system I'm in the process of building is this:    

• XFX 6770
• 600W PSU
• 4GB RAM
• AMD A8 APU 3.6 GHz processor, 100W (will mine LTC simultaneously)
• all on Xubuntu running cgminer (BTC) and cpuminer (LTC)

That PSU should be fine. But what if I add another XFX 6770 card? What effect will that have?

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[mufa23]

I'd buy a 700w single rail PSU.

I only spent 30 seconds searching, and quickly found this: http://www.newegg.com/Product/Product.aspx?Item=N82E16817182278
I'm not terribly happy about it not being 80 Plus, Bronze, Silver, etc. I've been running a few Rosewill HIVE 80 Bronze (or Plus. Can't remember) PSUs on some rigs, and they've been running flawlessly.

[deathcode]

I'd buy a 700w single rail PSU.

I only spent 30 seconds searching, and quickly found this: http://www.newegg.com/Product/Product.aspx?Item=N82E16817182278
I'm not terribly happy about it not being 80 Plus, Bronze, Silver, etc. I've been running a few Rosewill HIVE 80 Bronze (or Plus. Can't remember) PSUs on some rigs, and they've been running flawlessly.

You know the whole bronze/gold/platinun/unobtanium shit is just certifications right and kinda like a publicity stunt to get more money out of you, just like the HDMI Monster cables certified to 21 petabytes and shit selling for $150 when a regular HDMI cable is $10 anywhere else and does the same thing...
just saying

[c789]

Yeah - it's on its way to me now from Newegg. But does adding an identical unit double the power needed? I don't know if there's a specific ratio or if it doubles.

[crazyates]

I'd buy a 700w single rail PSU.

I only spent 30 seconds searching, and quickly found this: http://www.newegg.com/Product/Product.aspx?Item=N82E16817182278
I'm not terribly happy about it not being 80 Plus, Bronze, Silver, etc. I've been running a few Rosewill HIVE 80 Bronze (or Plus. Can't remember) PSUs on some rigs, and they've been running flawlessly.

You know the whole bronze/gold/platinun/unobtanium shit is just certifications right and kinda like a publicity stunt to get more money out of you, just like the HDMI Monster cables certified to 21 petabytes and shit selling for $150 when a regular HDMI cable is $10 anywhere else and does the same thing...
just saying

Mmm not quite. I upgraded from a 80Plus Bronze to a 80Plus Gold, and my Kill-A-Watt noticed a 30W decrease in the draw at the wall when mining with the exact same settings. That's a difference of about $40 over the course of a year. That's not marketing crap, that's what I've noticed for my Rig.

[crazyates]

The small system I'm in the process of building is this:    

• XFX 6770
• 600W PSU
• 4GB RAM
• AMD A8 APU 3.6 GHz processor, 100W (will mine LTC simultaneously)
• all on Xubuntu running cgminer (BTC) and cpuminer (LTC)

That PSU should be fine. But what if I add another XFX 6770 card? What effect will that have?

Id say you're fine with that 600W PSU. Your CPU will use 100W, another 100W for the rest of your system (overkill, but lets go with it), and those 6770s don't pull a lot of power, maybe 100W each. You could comfortably run 2 6770s and an A8 on a 450W.

[tacotime]

Any good 500w gold or platinum psu can power that.  You will never pull more than 400w with 2x 6770s on that setup.

[c789]

Thanks all. I appreciate your help.

[BBQKorv]

I'd buy a 700w single rail PSU.

I only spent 30 seconds searching, and quickly found this: http://www.newegg.com/Product/Product.aspx?Item=N82E16817182278
I'm not terribly happy about it not being 80 Plus, Bronze, Silver, etc. I've been running a few Rosewill HIVE 80 Bronze (or Plus. Can't remember) PSUs on some rigs, and they've been running flawlessly.

You know the whole bronze/gold/platinun/unobtanium shit is just certifications right and kinda like a publicity stunt to get more money out of you, just like the HDMI Monster cables certified to 21 petabytes and shit selling for $150 when a regular HDMI cable is $10 anywhere else and does the same thing...
just saying

Mmm not quite. I upgraded from a 80Plus Bronze to a 80Plus Gold, and my Kill-A-Watt noticed a 30W decrease in the draw at the wall when mining with the exact same settings. That's a difference of about $40 over the course of a year. That's not marketing crap, that's what I've noticed for my Rig.

Same here, after upgrading one of my rigs to AX1200 it did pull 32W less just with that modification alone. Not a huge difference but very easy to earn back the extra cost of a better PSU.