650W Antec earthwatts not enough for dual 7970's?

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CleanSlate

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Thinking about the long run if I decide to dual 7970.

Specs:

AMD 1100t x6
2x4 ddr3
7970 3 gig
Asus m5A97 motherboard
2tb WD
raid 1 dual 3tb HDs
1 x dvd-rw
Corsair H60
3 case fans 120mm or larger

Will be making custom water cooling later for both my 7970 (maybe the 2nd as well if I get it) and cpu most likely.

I have a serious doubt that this 650w psu could handle all that. Any recommendations would be appreciated. I was thinking about getting a pc power and cooling 900w solution or maybe seasonic or perhaps even antec.
 
Profumo said:
You'll be fine as long as you're not a bencher.
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What do you mean by "bencher"? I do run benchmarks and run burn-ins all the time to test for stability issues and check out new stuff... if that's what you mean.
 
Wouldn't push it. The x6 is a power hungry chip, and between that and a pair of 7970s...

No, wouldn't go that route.
 
I would guess two 7970's would put you at about 90% (584W / 650W) of your PSU's capacity if everything was at stock clocks/voltages. I wouldn't run a power supply that hard in my system.
It's hard to find a good review with a 1100t x6 and x-fired 7970's, so I had to make some guesses about what your system would use based on [H]'s review using a somewhat similar system (overclocked 2600k): http://www.hardocp.com/article/2012/03/28/nvidia_kepler_geforce_gtx_680_sli_video_card_review/2

There, a Crossfire 7970 setup maxes out at 584W (battlefield 3) with a 2600k overclocked to 4.8GHz. Here is why I think it would be about the same for your system:
The 4.8 overclocked 2600k should add about the same wattage as a stock 1100tx6 based on the 2600k review here: http://www.hardocp.com/article/2011/01/03/intel_sandy_bridge_2600k_2500k_processors_review/6
There the 2600k overclocked to 4.4Ghz was still using 25W less than the stock 1100t. The extra 400MHz on the 2600k (4.8GHz) in the test system used for the crossfire review should make CPU power roughly equivalent between your system and the one [H] used to get that 584Wmax power draw.

I did something similar when i picked out the 750W Seasonic in my sig. Wanted to able to run two cards down the road (well any two cards that aren't OC'ed Geforce 480's)
 
banned_user said:
I would guess two 7970's would put you at about 90% (584W / 650W) of your PSU's capacity if everything was at stock clocks/voltages. I wouldn't run a power supply that hard in my system.
It's hard to find a good review with a 1100t x6 and x-fired 7970's, so I had to make some guesses about what your system would use based on [H]'s review using a somewhat similar system (overclocked 2600k): http://www.hardocp.com/article/2012/03/28/nvidia_kepler_geforce_gtx_680_sli_video_card_review/2

There, a Crossfire 7970 setup maxes out at 584W (battlefield 3) with a 2600k overclocked to 4.8GHz. Here is why I think it would be about the same for your system:
The 4.8 overclocked 2600k should add about the same wattage as a stock 1100tx6 based on the 2600k review here: http://www.hardocp.com/article/2011/01/03/intel_sandy_bridge_2600k_2500k_processors_review/6
There the 2600k overclocked to 4.4Ghz was still using 25W less than the stock 1100t. The extra 400MHz on the 2600k (4.8GHz) in the test system used for the crossfire review should make CPU power roughly equivalent between your system and the one [H] used to get that 584Wmax power draw.

I did something similar when i picked out the 750W Seasonic in my sig. Wanted to able to run two cards down the road (well any two cards that aren't OC'ed Geforce 480's)
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I have to say I'm impressed by your reply and I certainly appreciate the time you put into the research behind it.
 
By benching, it's usually referring to overclocking to the max and benchmarking.

Those reviews take power draw from the wall. Considering the power supply is about 85% efficient (being generous), you're talking about ~500 watts pulled from the power supply. Of course, that is a game, simultaneous furmark/P95 will use more power.

Here's my breakdown:
A stock 1100T would use 125 watts max based on TDP. Realistically, that's somewhere around 100-120 watts.
http://www.techpowerup.com/reviews/AMD/HD_7970/26.html
Max power consumption while benching at stock is 270 watts. Peak gaming power consumption at stock is 190 watts. Overclock it and you will go higher.
At stock: 190 + 190 + 120 + 50 (system power draw for average system) = 550 watts.
How much power consumption goes up during overclocking depends on the overclock. Overclocking the 1100T without increasing voltage will probably add at best 20-40 watts. Adding voltage can increase wattage by 60-100, depending on the workload and degree of overclock.
 
How old is your PSU? If it's more than a couple of years old it would have lost a bit of that 650W due to capacitor ageing you should invest in a decent 800W+ PSU. If it's new then you should be fine running everything at stock speeds, but considering the overclocking headroom the 7970 has you really should think about upgrading the PSU to get the best out of your system.
 
slh28 said:
How old is your PSU? If it's more than a couple of years old it would have lost a bit of that 650W due to capacitor ageing you should invest in a decent 800W+ PSU. If it's new then you should be fine running everything at stock speeds, but considering the overclocking headroom the 7970 has you really should think about upgrading the PSU to get the best out of your system.
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Capacitor aging is a myth... Good quality PSUs (like this Earthwatt) do not have capacitors that degrade significantly over their typical lifespan. It usually takes more than 10 years for capacitor degradation to reach even the 10% level. By then, something else would probably have died first, usually the fan failing leading to the PSU overheating and failing.
 
No, I wouldn't run that setup on that psu. You're at about 600w right off the bat.Get a 750w if you aren't going to go the WC route, 800+ if you are. Pumps and the mess of fans can pull a significant amount of watts.
 
First, it is the older EA650 or the newer EA650 Green? They are almost completely different. Either way, you would have to use PCI-E power adapters to run CF on it with high end cards as they have 6+2/6 and 2x6+2 respectively.
 
Jorona said:
No, I wouldn't run that setup on that psu. You're at about 600w right off the bat.Get a 750w if you aren't going to go the WC route, 800+ if you are. Pumps and the mess of fans can pull a significant amount of watts.
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Like LigTasm stated, it depends on which version of the EA-650 the OP has. If it's the original version, it's marginal since it has only 45A (540W) total on its +12V rails. The newer EA-650D Green has 54.16A on the +12V rail.
 
I'd grab a quality 750w-850w PSU to give you some breathing room for OV and OC on your gpu's and cpu as well as your WC gear power draw.
 
You will run them with no issues but your PSU will get hot and the fan will spin and you will HEAR! :)
 
LigTasm said:
First, it is the older EA650 or the newer EA650 Green? They are almost completely different. Either way, you would have to use PCI-E power adapters to run CF on it with high end cards as they have 6+2/6 and 2x6+2 respectively.
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This is the older version I guess, it has 3 12v rails, 2x26amp and one that's 16 amps I think.

It's the non-green version.
 
Then you should upgrade. It will run dual 7970s fine in games, but you're really close to the power limits. If it's a game that is GPU dependent, but not CPU dependent, then power consumption from the CPU would be minimal, and most games will not max out two 7970s unless you're running eyefinity.
 
Tsumi said:
Then you should upgrade. It will run dual 7970s fine in games, but you're really close to the power limits. If it's a game that is GPU dependent, but not CPU dependent, then power consumption from the CPU would be minimal, and most games will not max out two 7970s unless you're running eyefinity.
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I figured I needed to upgrade.

Running eyefinity is really what I'm going for. I want to run 3x23" 1080p monitors and I'm really afraid that ~30 fps in bf3 and other demanding games will make me want to shoot myself.
 
I have a 600 watt power supply that would not power a 7970 OC w/boost but would power 2 460gtx. Here it says the basic 7970 crossfire setup runs almost 650 watts at full load in metro 2033 ( http://www.anandtech.com/bench/Product/508?vs=588 ). This is likley a system with one HDD, not much memory, and probably not a case with good cooling. With 4 HDD, 6 sticks of memory, 6 fans (some are big and have lights), 1 optical drive, optical audio, output to speakers, 2-3 lights, and 8-10 USB ports jampacked full of things; I worry the 900 watt I bought to power the one card will not be enough for 2 when/if I go crossfire on this.

I thought this might help cause according to everything I have read my 600 watt should have powered things up. Even with most that disconnected my 3-5 year old 600 watt DID NOT want to boot the 7970, even trying different rail combinations.
 
This topic is why only Intel goes in my builds.

I would say the single 7970 can run everything maxed out so why not just wait for the 9970 and run that. Spend the cash now on a nice 80+ gold or platinum bigger PSU and wait.
 
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