660 Ti 3GB SLi or 7970 3GB Crossfire for 30" Gaming

[flopper]

And I'm of the mindset that people like you are delusional. There hasn't been a game since Crysis where that additional power provides actually meaningful difference in visuals. Is Metro that much better looking with DOF that It's worth cutting your frame rate in half? The difference between console graphics and medium/high settings is huge, but comparing that medium/high to ultra, you need a reference and a lot of squinting to see the difference in most new games while taking a huge fps hit.

I don't mind people striving to get the best visuals and upgrading their hardware or else I wouldn't be here, but to ignore the massively diminishing returns, you'd have to be willfully ignorant.

One reason BF3 for example is popular, it looks absolutly great and has physics.
to bad the game sucks in gameplay and design.
I play fps games low, rts and such like GW2, on max I can go for.
seems like a good way to game IMO.

 

[RussianSensation]

I was just trying to tell the OP that a 750W PSU will not be enough for 2 overclocked 7970 using an extreme example which shows the maximum power consumption of one card. Considering that the OP may try and overclock his 7970 further than the GE it is good to see what he might expect. You are doing a fine job defending every aspect of the 7000 series cards all over these forums so this overreaction is not surprising. The comparison with the 680 was never intended because it has nothing to do with this thread.

I understand that a 7970 consumes more power when overclocked, 240-245W in overclocked states as shown by Xbitlabs and Hardware.fr before. 250W * 2 = 500W. Those 750W units are rated to run at 750W 24/7. The OP upgraded to an 850W unit anyway but a 750W can easily handle 2 overclocked 7970s. It's not about defending the 7970 but looking at the actual power draw of a specific card and how it falls into the PSU requirements. You were showing a graph with the card pulling > 270W which is not what a 7970 draws.

 

[Ferzerp]

Either 680's or 7970's are what you want. 660 is not going to be enough for 2560x1600 unless you don't care about lowering settings.

 

[Crap Daddy]

deleted

 

[turn_pike]

You are doing a fine job defending every aspect of the 7000 series cards all over these forums so this overreaction is not surprising. The comparison with the 680 was never intended because it has nothing to do with this thread.

Umm, RS did recommend going for the 670 route.

Just go with GTX670 SLI. You also get Borderlands 2 for free with both 670 cards. You can sell one of those games. Since it's very knew, probably can sell it for $40.
[...snip...]
OR Asus Direct CUII 670 for $404 after the same $15 off coupon. Works for 2 cards if you order them separately. So that's $808 for the quietest high-end cards this generation.

I wish the NV guys would fire back using noise as part of their argument, complete with graph and such. I cant be the only one who gets free electricity and only care about the noise these cards are making at load. Especially so for AMD cards since if they cant be quiet at load then bitmining is often out of the equation as well.

 

[Crap Daddy]

but a 750W can easily handle 2 overclocked 7970s

This is simply not true. While CF with stock 7970 will get you up to 640W power consumption under load as seen here:

http://www.legitreviews.com/article/1834/11/

Two overclocked Sapphire 7970 at 1075/6600 will need 821W for the whole system as seen here:

http://www.tweaktown.com/articles/4...o_cards_in_crossfire_overclocked/index16.html

I would be very careful in choosing the wattage and the quality of my PSU if I would like to run two overclocked 7970.

 

[guskline]

thm1223: Enjoy the new rig! WOW, what a screamer that's gonna be. Keep us posted! RussianSensation makes a good point about power draw. I bought a Kill-O-Meter device. Not the most accurate in the world but better than "guesstimates"

 

[toyota]

thm1223: Enjoy the new rig! WOW, what a screamer that's gonna be. Keep us posted! RussianSensation makes a good point about power draw. I bought a Kill-O-Meter device. Not the most accurate in the world but better than "guesstimates"

BTW, Crap Daddy that 821W day was for 3 Sapphire 7970s OC'd not 2 per the chart. 2 Sapphire 7970s under load is 539 per the chart. AND the Power draw is the most extreme using Furmark where you mention 2 stock 7970s CF using 640W.

did you even read anything the link? it was 3DMark 11 not Furmark. the 821 watts was for 2 overclocked 7970s NOT 3. the chart clearly says that not to mention the following comment does too.

Power Draw sky rockets when overclocked and you can see the overclocked CrossFire setup actually draws more power than the three-way CrossFireX setup when running at stock.

 

[guskline]

toyota, I stand corrected! I edited my comments and apologize to Crap Daddy. On a lighter note, maybe that's why I chose 2 670s in SLI for my 750W PSU

 

[Crap Daddy]

toyota, I stand corrected! I edited my comments and apologize to Crap Daddy. On a lighter note, maybe that's why I chose 2 670s in SLI for my 750W PSU

I know that power consumption on Tahiti cards when overclocked seem a bit crazy but that is the situation. I also understand that for an enthusiast these things don't matter so much as the raw performance. But when somebody is purchasing such a setup it is important to know what you are facing and balance the few more FPS with increased costs related to the performance boost.

 

[guskline]

I know that power consumption on Tahiti cards when overclocked seem a bit crazy but that is the situation. I also understand that for an enthusiast these things don't matter so much as the raw performance. But when somebody is purchasing such a setup it is important to know what you are facing and balance the few more FPS with increased costs related to the performance boost.

Agreed! Perhaps the "lesson" is if you are buying 2 Very high end cards to run in CF power draw might be a problem, especially, for serious OCing.

Nvidia "solved" this by locking down, for the most part, the OCing ability of the 600 series cards (Classified & Lightning excluded)

I also agree that the last few fps gain sometimes comes at a rediculous price in power draw and perhaps danger to the GPU/CPU. My SB 2500ks are OC'd below but not to the very upper limit. I preferred to have a solid OC but STABLE OC (i.e. run evry diagnostic test I could without crazt temps or BSOD). GPU OCing appears the same.

I'm a lousy gamer but I've never had a video game character scream at me that if he had just a few more fps he could have killed the other guy!

 

[RussianSensation]

I know that power consumption on Tahiti cards when overclocked seem a bit crazy but that is the situation. I also understand that for an enthusiast these things don't matter so much as the raw performance. But when somebody is purchasing such a setup it is important to know what you are facing and balance the few more FPS with increased costs related to the performance boost.

Dude, you keep linking these reviews to prove a point but do you actually look at the test system being compared and how that relates to the OP? Legit Reviews total power draw uses an Intel Core i7-3960X system using an X79 motherboard. The X79 3960 combo uses 125W more power than 3770k IVB systems the OP is buying:

It's been shown at least 10x on our boards that an aftermarket overlcocked HD7970 @ 1150-1165mhz draws ~240W. If people at LegitReviews or elsewhere want to put 1.25-1.3V into a reference 7970, that's their choice. No reference 7970s were ever recommended in this thread. If you actually owned a good after market 7970 (such as the Vapor-X recommended in this thread) you'd know it needs just stock voltage to reach 1150mhz (that's 1.175V). Reference crappy overclocked 7970 cards that have nothing to do with what's being recommended in the said thread.. The voltages needed to overclock the Vapor-X 7970 have nothing to do with how a reference 7970 responds and thus you cannot infer power consumption numbers by linking reference 7970 cards. At the very least you'd have went out and looked at what "comparable" after-market 7970s draw and how well do they overclock on stock voltage.

Asus GTX680 1212 mhz = (451 - 231) * 85% efficiency = 187W
MSI Lightning 7970 1165mhz = (543 - 243) * 85% = 238W

Asus HD7970 1000 / 1400 MHz @ 1.050V : 163W
Asus HD7970 1150mhz @ 1.175V = 237W
http://www.hardware.fr/articles/853-5/asus-radeon-hd-7970-directcu-ii-top-test.html

MSI 7970 Lightning stock 1070 / 1400 MHz @ 1.174V : 211W
MSI 7970 Lightning 1100 / 1775 MHz @ 1.174V : 225W

It is only when you increase GPU voltage past 1.225V on the 7970 you get above 250W
http://www.hardware.fr/articles/853-8/msi-radeon-hd-7970-lightning-test.html

Again a stock HD7970 Vapor-X likely consumes around 225W. 2 of those is 450, around 500W overlcocked up to 1150-1170mhz.

You cannot compare reference 7970 to an after-market 7970 for 3 reasons:

1) A GPU that runs hotter consumes more power. Reference overclocked 1200mhz run hotter than aftermarket 7970s;

2) Many aftermarket 7970s have upgraded VRMs that are far more efficient. Vapor-X has Black Diamond Chokes.

3) Aftermarket 7970s such as VaporX, MSI Lightning have binned 7970 chips. They reach 1100-1150mhz on stock voltage. Using a review that puts 1.25-1.3V to get those clocks is irrelevant for what's being recommended. Thus linking power consumption for those other cards that need uber high voltage to reach good clocks is irrelevant.

That's the whole point behind buying after market 7970s for air cooled overclocking.

This is simply not true. While CF with stock 7970 will get you up to 640W power consumption under load as seen here:

http://www.legitreviews.com/article/1834/11/

Are you ever going to stop comparing apples vs. oranges? Furmark =! Gaming power consumption.

The graph clearly shows 489W of power in gaming, not 640W. That's on a i7-3960X / X79 platform.......

The HD7970 Ghz Edition doesn't draw some 270-300W of power as you are making people here believe. Not even the Sapphire Toxic with 6GB of VRAM at speeds of 1100mhz draws more than 250W in games. Using Furmark power virus to derive power consumption numbers in real world is either trolling or not understanding how Furmark works. It is no wonder Furmark killed so many 4870/4890/275/280/285s and I am sure other cards before both companies clamped on its unrealistic use.

2 good after-market 7970s at 1150mhz @ stock voltage will draw less than 500W of power in total in games. Also, there isn't even a need to overclock the Vapor-X since HD7970 GE / 1050mhz+ CF > GTX680 SLI. The Vapor-X CF setup is far less efficient than GTX670 SLI of course but it is the fastest dual-GPU setup for 2560x1600 outside of going for GTX680 MSI Lightning SLI for $1200. Both setups are good options depending on what the users wants, which is why I recommended 670SLI in this thread for the OP.

At the same time you can't start comparing 240W 1150 mhz 7970 against stock 670s and then not take into account that one card is way faster than the other at those speeds, while a 680 @ 1200mhz will also draw more power than a reference 680.

At just 1080mhz (that's still < 225W of power right here), the 7970 is 10% faster than a 680 and 20% faster than a 670 at 2560x1600:

With Sapphire Vapor-X going for just $443 with free shipping after coupon code, it's not easy to recommend a 670 for 2560x1600.