Is 32 amps enough for gtx 670 ftw

saige1r

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Feb 28, 2012
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I read that the GTX 670 requires 30 Amps, but didn't realize that the EVGA FTW edition would require 38 Amps. Silly me.

My 500W CoolerMaster PSU is rated at 16 amps, on 2 12V rails, which puts me at 32 Amps. Would I risk damaging my system if I tried to install this card?

I have an OC'd Q6600 (at around 1.42V iirc), 1 HDD, 1 dvdrw, 6 fans, and 3 or 4 USB devices on my system.

Under full load (prime95) with a GTX 460 SE, my system draws less than 400W from the wall, just for reference.
 

saige1r

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Feb 28, 2012
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Ok, thanks for the input. FWIW, this PSU has served me well for the past 4 years. I was hoping I wouldn't need to upgrade until I got my new CPU/mobo, but oh well. Now I have an excuse to get a new 80+ PSU.
 

saige1r

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Thanks, that was gonna be my next question. From what I've read, the GTX 670's are pretty efficient, so I was leaning towards a 750 watt, but maybe the 850 would be more future proof.

Just curious, but what could happen if I did try to install this? Would I possibly fry the card?
 
G

Guest

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that is an outrageous claim!
power_maximum.gif

even @ 200 watts (17 amps), the max on your PSU; i would not trust a cooler master to deliver that :(

man 30 amps and some of you co-sighed that B.S? shame on YOU!
 

4745454b

Titan
Moderator
You guys do realize that the GTX670/680 are the new GTX560TI cards right? These are the sub 200W cards, not the big 250W cards like the GTX480/580. As Looniam's chart shows we are talking about <200W. You don't need 40A or 600W to power a machine with a GTX670.

That said I wouldn't use a 4 year old CM PSU. Time for a new one.
 

well to be fair, 40A is a 500w psu and I would recommend that to a 560ti as well. Especially considering he is OCing his cpu and his gpu will also at least be factory OC'ed.

Quality 450-500w for single card and Quality 650-700w for 2 seems to be about right.
 
I am with the boat of not NEEDING 700-800 watts for that system.

My 5870 with a I72600K @ 4.4 has NEVER past 300 watts(thanks to just how good this cpu is for power consumption) at the wall.

Also it is a good idea to take into consideration efficiency. Higher efficiency power supplies will draw less from the wall due to the lower power waste.

Power supplies are rated in DC power so efficiency does not change the output power, just the input power required to make said output power.

If you have 32 amps(should be listed as a combined output[384 watts R1 + R2]. you can not always just add up rails since they normally get that power from one larger rail), you are in the range of most 400-450 watt power supplies, but after 4 years. the power supply may not still put out its full rated power. This being said, Cooler Master power supplies are sometimes unable to meet the label specs to begin with.

@ looniam, the EVGA link entertains me :) AMD says I need a minimum of a 450 watt power supply for a 5770. It has been going for years on a 300 watt power supply.

 
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Guest

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:lol:

i know i experienced much disdain using it since all OEM specs over compensate. but i could not find a specific power consumption benchmark. . . . yet, hardware canucks is down ATM.

i would believe that a FTW would not be much more than stock but i like to avoid conjuring numbers and needs from between my ears when possible. :)
 

I notice that too. been like that for a while. The main page is working but many reviews are down :(
 

cuecuemore

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If OP's PSU lived up to what it advertises, it would be fine for a single card. Problem is that it failed in multiple tests at less than 350w DC. This is right around where OP said his system was sitting right now, so even though the 670 only pulls **20w** more than his current card, I'd say it's a great time to upgrade to a high-quality PSU.
 

saige1r

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Feb 28, 2012
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Wow, thanks for all the useful posts guys! I think I'll hold off putting in the 670 for now, while I wait for a deal on a good 80+ certified PSU.

EDIT: Ok, my toddler is finally in bed, so I got a chance to do more testing. I ran the EVGA stress test on my system and checked the kill-a-watt. I saw 336 max wattage being drawn from the wall. GPU was at 99% during testing, and I have it OC'd and set to 975mV.

From what I've been reading in this thread, I may be able to run my 670 tonight. Very tempting to try. I might underclock the 670 and lower the voltage a bit while I wait for that PSU deal...

Thanks again for all the help all!
 

4745454b

Titan
Moderator
I don't remember what the GTX460SE draws. I'm sure its around 150W however. The draw of the GTX670 isn't much more then that. Downclocking and more important undervolting should allow you to add that GTX670 in while waiting. You won't get the full performance but it should be faster then that SE.
 
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Guest

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GeForce GTX 460 SE review
Subjective calculated GPU power consumption = ~ 160W

ya know as much as we all are ragging on that cooler master PSU, myself included, he just may get away with it FOR NOW

still it would be wise to upgrade it and keep the load light until then. no sense in taking out a whole system over $60 (the cost of a PSU) just to play with a $400 card.
 

masterjaw

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Jun 4, 2009
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Have you tried using the psu calculator to check?
PSU Calculator

This would also include the usage of the other PC components. Then convert the wattage to amps then compare that to the total amps delivered by your PSU. Though I do think that coolermaster psu was not true rated. Might as well be safe and get a good 600w PSU.

And you don't want to run a PSU at 99%.
 

saige1r

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Feb 28, 2012
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Just as an update, I put the power target to 95% and my system now draws under 300 watts from the wall, and runs faster than my 460 SE. Pretty amazing. Tempted to buy this PSU from newegg:

http://www.newegg.com/Product/Product.aspx?SID=vNj9EKrEEeGo70LSzz4jvwc04ea&AID=10440897&PID=1225267&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-cables-_-na-_-na&Item=N82E16817171054

Looks like mostly good reviews on amazon and newegg, and is only $67 after coupon and rebate. Might wait a little longer to see if I can find something modular since my PSU seems fine atm.
 

The only problems with the psu calc is that it does not give you the 12 volt amperage. So unless you assume ALL power is from the 12 volt rail then it is not quite as good. Still better then nothing(and over the years has got much more accurate. I remember it giving numbers well over real world power use).

 

masterjaw

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^ Yup, I knew that the results weren't really accurate per se but at least you have some basis for comparison. :)

And having some headroom might be more beneficial and cost-efficient on your part in the long run. :)
 
Can never have too much power :)

40% more(then average power use) is my general rule, but its for efficiency more then anything as a power supply is more efficient loaded about 50-60 percent(or damn near peak for a passive power supply, but i don't have one of those.).