Is Crossfiring worth it?

I was planning on getting a 7970 and a 750w PSU. So that in the future when my performance started drop off i would just buy a new 7970 crossfire them and be on my way. Is this just wishful thinking or would it actually be worth doing. I realize the 7970 is still new. Its just one of the ideas i had since i had decided i wanted to build my own pc. But i know some people have trouble getting crossfire to work on all games. Will they improve the technology behind it or is this just a gimmick that will soon fade away?

i think you might want a bigger psu for 2 7970's but in my opinion 1 7970 is enough for any gaming you plan on doing and by the time its performance isn't enough just get a newer card or a new rig entirely... I am assuming your using it play games because you didn't say 

Yes it will be for gaming. Originally and this was months ago. I was thinking i would include a large psu for my build so that years later i could just buy another 7970 and crossfire it inorder to save money. But from what ive saw on a few videos and elsewhere it almost seems like crossfire is more of a gimmick than a way to save money. I was trying to see if that was the case.

I always say go with one video card sli and crossfire can be headaches. if your one video card doesn't do it upgrade to a more powerful card I think you and your PC will be happier with that route.

Yeah i might bump my PSU down a little.

atm, there is not a more powerful card. that said, you should be fine with just one, and possibley a future upgrade to cfx

I bought a 750 watt PSU so in the future i can Xfire 2 7950's (i only have 1 so far) for 2 7970 id say get 850 watts or higher.

A 750w is more than enough for crossfire. A system with a single 7970 barely reaches 400w on full load.

"http://www.guru3d.com/articles_pages/radeon_hd_6850_6870_crossfirex_review,4.html

 

With two 6870s under full load in their system, their PSU pulled 421W from the wall outlet.  Their CPU was idling, so 150W needs to be added for an overclocked 3770K under full load.  This makes the PSU pulling 571W from the wall outlet if the two 6870s and the 3770K are under full load at the same time.  If the PSU is 85% efficient while pulling 571W from the wall, then that means the system is pulling about 485W from the PSU.

 

Even if I add 200W instead of 150W, that still comes out to being only about 530W being pulled from the PSU (that is, 421 + 200 x .85 = 527.85)."

I dont mean to sound like i dont want good advice. But i wasnt asking about whether the psu i selected would support 2 7970s. I was asking if its worthwhile to plan on crossfiring it seems like there is a lot or headache involved with the process.

I think VanillaGorilla is right. You can make it with 750w, but barely. That depends on your other components. A mechanical HDD take 10w at full throttle. An i7 can take 75w.

Another factor to take into account is longevity. The older you PSU gets, the less effective it gets. The capacitors wear and the effenciency drops. That is why you should give your PSU some breathing room. That's why the Tek crew say never to cut corners in their videos.

Scaling on CrossX or SLI is around 92% (2 cards = 1.92x the performance), which is absolutely incredible. I'd go for it. I get this information from this article I've read recently:

http://www.hardocp.com/article/2012/12/04/gtx_680_vs_radeon_hd_7970_multidisplay_showdown/

I've never crossfired myself, so I can't give you my honest oppinion.

That card should be good for about 3 years, and by then you might as well just get one of the latest GPU which should have around the same performance as a crossfired 7970.

Unless you want to play on multi monitors or upgrade to 1440p, then crossfire is probably not worth the trouble.

If you're playing at 1920x1080 don't bother. Crossfire or SLI these days isn't necessary for playing on a single monitor. I haven't played a game I couldn't max out on my GTX670 at 1920x1080.

That's absolutely true. There's no point having more than one GPU if you don't go to very high resolution. The fact has even been exposed that you get better performance by enabling ultra quality at the highest resolutions. If I were to get dual GPUs, my endgame would include 3 monitors.

I think that settles it for me then. IS my 750w psu to much for a single gpu system?

 

650w would do just as well. If you feel like saving a few bucks, downgrade to 650.

I know... the question pertained to the future

keep in mind that if you're planning on using crossfire the cards may not be available

Power supplies are usually designed to be most efficient at around half the load and should't be as noisy as those near full load.

 

Can we all just stop being stupid and put aside the whole "SLI and CFX can be a headache" argument? I've run both SLI and CFX before, and I've never had a problem with either of them. The vast majority of games out there support the technology, and it almost doubles your graphics horsepower. The only reason anyone argues against SLI or CFX is because they either have never experienced it before or because they're jealous because they can't afford it themselves.

He's only saying that in 3 years, buying a second pair of 7970s would be near impossible.