Crossfired 7970 Lightnings or SLI Asus 670 DCIIs?
 

So I'm finally doing my gpu upgrade in the next 2 weeks. I've narrowed down to my two favourite choices..and this is what I've got to decide. Crossfired 7970 lightnings? or SLI 670 DCIIs? Note : the DCII's are the NON TOP edition.

I've narrowed down to these two options as they are both excellent in terms of keeping the cards cool and quiet (my reference 5850's have driven me mad with their leaf blower cooler)

From what I understand the 670 is very close to 680 performance even at stock clocks, but 670's tend to generally only be good clockers if they are models based on the 680 pcb (gigabyte WF3 for example) but i'm pretty sure the DC2 has the 680 pcb (although if someone knows for sure it'd be great to have this confirmed as the model I am looking at is the NON TOP version, yet almost all reviews only review the TOP)

In terms of the 7970s, they are the overclocking Kings this round it seems...especially the Lightning series. So then there is the 7970 vs 670 in raw performance.... the 7970's should push the higher FPS in most games from what I can see...but its all the issues I am worried about..

So, 7970 crossfire users and 670 SLI users alike, i'd love to hear from you. How are your cards going? what's going well? any games giving you a headache due to flickering or negative scaling etc?

that's another thing - negative scaling - I've experienced this a fair few times with my 4850s and 5850's...looking at benchies it seems like 7970s still have negative scaling issues here and there nowadays..but Nvidia users, have you experienced this? Don't think i've ever read about a SLI rig suffering from negative SLI scaling.

Welcome to TPU! Please fill-in your System Specs through your User CP.
The two (actually four:)) GPU's you are thinking about are both good performers. What resolution are you gaming at?

There are a few factors you should consider here.
The Asus DirectCUII is an awesome cooler, and incredibly quiet even after overclocking. While you're looking at a 670, I believe the 7970 also comes with this kind of cooler.
You are correct that the 7970's are the kings of overclocking, but the main thing to consider for this SLI is how many monitors you are running at what resolution.
The 7970's come with 3GB of memory, very important when considering resolutions above 1200, and when you want to strap on MSAA, TXAA, AA, Supersampling, and high res textures. These are going to eat away at your VRAM, and while have two 670's with 2GB each, does not mean you will get 4GB total memory, as VRAM doesnt stack in SLI, each card just uses its own memory to store the data for the frames its processing.
The GTX 670's are monster cards, and I'd always choose one of those for 1080p gaming despite being an AMD user myself, but for the price, the amount of VRAM and the general performance, I'd roll with the 7970's for crossfire on multiple monitors at high resolution.
However, one thing to consider, is the frame latency on the 7950's and 7970's, which is a miniscule amount higher than the GTX 670's and 680's, which have a lower frame latency. Most people dont notice, but for avid enthusiasts, they might notice a few fractions of a millisecond delay in frame processing.

Thanks guys,

I'm actually not new here, my old username was "Enmity" but when those darn hackers hit TPU I lost the ability to log in. So I emailed Wizz to get it sorted, he said the Servers were just being bombarded so just wait for the "forgot password" email to arrive. It never arrived and I've just been busy. So tonight I went to TPU, go to log in..DOH, that's right lol..so I figured it was quicker to just start fresh with Enmity NZ.

Updating specs in a sec.

3570k@4.6
8gb 1600mhz Mushkin frostbite
HX850 PSU.


Currently only running a Samsung XL2370 monitor (1920x1080) but my next purchace is going to be a 27ish" 2560x1600 monitor :)

Edit:
regarding the DCII's yeah the 7970 comes in a DCII flavor too, but unfortunately those things are 3 slots, rendering my soundcard useless due to slot configuration. :(

This is something I wasn't aware of, great info there thank you :) This is exactly the kind of info I am wanting to learn as I am extremely anal when it comes to game "smoothness" I always play vsynced also.

Edit : system specs updated :)

I will state that from personal experience I prefer Nvidia to AMD when it comes to dual card set-ups.

Please remember not to double post. Use the "Edit" or "Multi-Quote" feature:)

Thanks Hammer, Nvidia tends to be the general consensus when it comes to multi-gpu rigs for sure. I've never owned an SLI rig, just a single 7900GS and single 8800GTS 320MB lol...other than that I've just really been Crossfire 4850s/5850s

Nvidia SLI intrigues me :)

Ah yes, I'll make sure to edit next time.

I have used two gtx 570s in sli, and switched to 7950s in crossfire. I personally went to amd because if the extra gram, and everybody will tell you the 7900s scale better with multi montors, but the gtx 670 is hands down amazing for 1080p gaming.

At 2560x1440/1600, a single 7970 has around the same performance as a GTX 680. Going by this review, the 7970s seem to scale well at that res. Unfortunately, the latest review for SLI GTX 670 I can find doesn't test 2560x1600.

Don't get the 7970 DCII. It will make you miserable.

Keep in mind the 12.11 drivers boosted the 7970 performance a lot.

Lightnings Definitely

Thanks for the feedback so far guys. Sounds like its neck and neck between these two options.

I just picked up one Asus DCII 670 and it's stupid fast, can't imagine what two would give.

What did you upgrade from man? Right now 2 670s or 7970s is overkill I know, but I dont upgrade often so want my graphics choice to still max out games in 1 or 2 years time. Having 3 kids under 5 means no expendable cash nowadays haha.

I'd make sure you take care what monitor you buy. The 7970 Lighting's don't have dual link dvi so it may mean using display port connectors. In W1zz's review he had problems on that side.

I'd consider getting Asus Matrix 7970 instead. As for scaling, yes Nvidia has a better rep but I've seen no problems so far (except in shoddily coded games).

Thanks man the dual link dvi is a good point that I had overlooked. Thankfully I at this stage would only ever want a single display capable of running 2560 as the bezel when dealing with multi monitors is just not something id cope with well lol.hdmi can handle 2560×1600? If so then I dont mind about dual link dvi. Doesnt the lightnings come with a dp adaptor too?

Edit: the matrixs are too pricey for my budget unfortunately here in NZ, sexy card though!

Just get couple of these:
SAPPHIRE Vapor-X 100351VXSR Radeon HD 7970 GHz Edi...

Yeah those vaoor x models are really nice and have the dual link dvi but here in nz they are $70 more than the kightnings I can score. Pushing it outside of my budget unfortunateoy

I run 2560x1440 with a single 7970 or 680 and am perfectly happy.

Perhaps you can link a website from where you will be buying then and specify a budget? would make things easier.

After reading the initial post I'd like to say that:
-in Crossfire, your overclock is limited to the worst of the 2 cards possible overclock.
-the asus DCII 670 are too expensive for what they give and they are very large while they dont perform better (esp since they dump heat in the case) than other aftermarket coolers (msi etc). Choose another option as the cheapest DCii in the UK is £50 more expensive than over 670 with aftermarket coolers. (found MSI 670 power edition for £70 less than cheapest DCii)
-the 7970 are unarguably better and cheaper in the same time but the MSI lighting model is actually not good in value-performance so u might aswell prefer to buy nVidia at that price. (in the UK overclockers.co.uk offers them at £360 (7 more left atm at this price) casual price is over 400).
-if you cant find cheaper MSI lightinings, maybe try sapphire vaporx 3GB models.

Lastly, if I had to choose between nVidia 670 and AMD 7970 overclocked/aftermarket cards at around the same price (as in your case) i'd pick nVidia mostly for lower power consumption and supposedly better drivers (esp in 2-card configs) although I never owned SLI or Xfire to talk with personal experience.

Being a crossfire owner of a 6970s and previously 5850's & 4870's AMD's drivers were a lot lot better in the early years compared to now.

SLI has its own troubles too but afaik, most of the time it just works

Thanks again guys for all these replies, here is the website I use. http://pricespy.co.nz/category.php?k...s=l=s105265756 :) I know the performance of the 670dcii and 7970lightnings arent much b3tter than reference, but the temps and noise is much lower. Particularly the noise being low really appeals to me and im not really comfortable with doing a full water loop so want to get cards that are cook n quiet out of the box :)

7970's probably would be faster. You don't need a full waterloop for it either. But I can highly understand getting 670's in sli just because they have a 75 watt lower tdp. You will probably be able to overclock higher because of the lower temps also.

Probably not since the definition of TDP of AMD and nVIDIA differs.

I would go for 2x HD 7970 lightnings, these cards are just amazing with 3Gb VRAM and Ocing capability. 2x GTX 670 is not a bad choice if you like NV cards though.