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So I'm curious about this and I've often thought about it over the years. In the past scaling with either cards didn't work out very well and you always used to run into issues when doubling up cards. They'd run too hot, too noisy, games wouldn't support them, they'd cause glitching, and of course the performance issues that have been identified by TR.

However, most of those issues have been ironed out and Sli/Crossfire is now a relatively stable and mature technology. With the newest release of graphics cards, it leaves a lot to be desired as far as performance increase for the amount of money you put in. Both Nvidia and AMD have higher end solutions, but they remain out of reach for the majority of consumers ($500+ is a lot) and they don't really increase performance THAT much over the past generations.

Which leaves me wondering about how flexible and how cost effective it is to double up on a older graphics card and simply skip a newer generation in todays graphics card market.

I currently own a 7870 and the few benchmarks I find while looking around point that adding a extra 7870 will add an additional 50-90% or so FPS onto most games (depending on the game depends on the gain, cpu bound games for instance wont see it). A 7870 would cost me about $150... I can buy one for even cheaper on eBay. Now for comparison, in order to get remotely that sort of FPS boost I'd have to go to a R9-290x or a 780 which costs a heck of a lot more and still falls short of that sort of boost to FPS.

I am aware that newer cards have newer technology in them, which is something I'm quite interested in (especially the R9 series). Trueaudio for instance is something I'm very much looking forward to, but skipping a card and waiting another two year so till the next gen comes out shouldn't put me that far behind in terms of adoption of new technology. Since Mantle may work with older cards(?), I still may see support for it on my 7870.

Another thing I'm quite interested in is using varied graphics cards in crossfire (or sli). It's ill advised I'm sure, but AMD graphics cards have been capable of this for quite a few generations. No one has really done a take on this or the impact of such setups, which leaves this to be a black hole as far as information goes. Even something as simple as a R9-270x with a 7870, which should be almost identical.

I'm curious what your opinions are on this. It'd be great if TR started looking at this direction as well, seeing as a lot of people are rocking older gen hardware and are looking to upgrade in various ways, this sort of setup is becoming more and more lucrative and common. When sites do test crossfire or sli it's always the latest and greatest doubled up, but that sort of thing doesn't really apply to most people, even if it's a great curiosity to behold. People are definitely more likely to buy two 7950s or 7870s compared to two R9-290x or 780s. The price range and scope is completely different.

I'd love to see the price plots at the end of hardware reviews with low (maybe), mid-range, and mid-high end crossfire setups in it from last gen. Those actually actively compete against newer, faster cards, like the 290x and the 780.

I think you should do it since AMD now has the frame pacing drivers. I have been running SLI 560tis for almost 3 years. Over the past year Tearing and microstuttering are down at least 75% or better from when the system was new. I have not noticed any tearing or stuttering besides the nomal to high settings and low frame rate with my 1gb frame buffer. I will still take mny 2 560s over a 580 any day...unless it was a 3gb model:) then I would find another one and SLI those:)

I originally built the system with SLI since the performance was a good bit better with 2 560's Ti's then 1 580 and a good bit cheaper. I even got lucky with the cards and they both came off the line back to back from EVGA...serial #'s are the same but the last # and they were born seconds apart. On top of that they are stable at 1.075v 970 core 2400 mem. 1.100v and they can run at 1000+ so I got 2 good cards.

I think AMD's Crossfire drivers will just get better from this point on. Scaling is very good from what I have read on the 7870's and they usually overclock ok too. I know my 560s scale great on pretty much everything, But you will always have a problem title from time to time. MSI afterburner and most overclocking software will let you select linking the 2 cards clockspeeds/voltage ETC when overclocking so you can find the stable overclock while running crossfire/SLI.

In my opinion, if you can get the sort of performance that you need with a single Radeon R9-290 (non-X) or GeForce GTX780 (non-Ti), you really don't want to mess with SLI/Crossfire of lesser cards, even if it's a little less broken than it used to be.

That makes it more plausible to expect that the people who do use multiple graphics cards are likely on the bleeding edge with a pair of the fastest cards available driving a 4K display for twitch gaming rather than a pair of low-to-mid range cards driving a low-resolution monitor.

.

What I'm trying to suggest and query though is if this is now cost effective. A single card is a great idea, definitely, but it may be a lot cheaper to go with two cards over one if you're now upgrading.

There are a lot of benchmarks out there that support what you are saying. Even in 1080p, often considered low resolution in PC gaming, which many dismiss for xfire. Interestingly I found a 7850/7870 xfire match benchmark. Frame pacing/latency is not address however.
http://www.techbuyersguru.com/Frankenfire.php
Edit:
I'd also like to add that I disagree with JustAnEngineer. I think a lot of people with mid-range gfx cards would be interested in simply adding another mid-range card to as an upgrade. With both companies improving scaling; I think it becomes more and more a viable option.

I had a single GTX670, and added another one, thinking SLI is a pretty safe bet. Purely from my experience, it's not. That's why I now have a single GTX780 and got rid of the 670s. There are just too many little compatibility issues and sync problems, not to mention the power and cooling concerns.

clone wrote:

wonderful times indeed and if you give up on FSAA, a feature that is sorta redundant by 1080P it gets even better.

Stop saying this! Stop! Stop it right now! FSAA is *never* irrelevant! If we had gigapixel displays, it would still be relevant!

Don't ever say this again! You're spreading a malicious and mal-informed lie!

I personally think that its still too early to invest in XFire/SLI, even as a cheap upgrade. I think in 6-12 months we can be confident that the problem is fully resolved. Keep in mind that super high resolutions is broken right now with 2 cards. http://techreport.com/blog/25399/here-w ... ry-matters

You are better of putting that money aside and getting a nice single card when you can afford it. Also keep in mind that two cards require more energy and produce more heat, which may or may not be an issue.

For me, having extra vRam is the most important because I want freedom to run high-res texture mods. Fully modded skyrim can easily use 2+ GB, the next game they make will probably go into 4+ territory. Getting 2 cards usually means having less vRam, and next gen games will be pushing the vRam envelope now that the new console generation is out.

auxy wrote:

clone wrote:

wonderful times indeed and if you give up on FSAA, a feature that is sorta redundant by 1080P it gets even better.

Stop saying this! Stop! Stop it right now! FSAA is *never* irrelevant! If we had gigapixel displays, it would still be relevant!

Don't ever say this again! You're spreading a malicious and mal-informed lie!

clone may be more blind than you, auxy

*Isn't the term 'FSAA' a bit redundant? Is SSAA being implied, or something else?

I just have to chime in again and try to get you to pull the trigger on a second 7870. I think since you can get a Second card for so cheap I think you should by another card, run crossfire and play with it yourself and come to your own conclusion and experiment with the technology that is getting better not worse. If it does not work out I am sure you could sell it and get the majority of your money back.

Besides the 2 gb frame buffer is good enough to be running higher Anti aliasing setting's Anistropic filtering settings for 1920x1200/1080 resolution. Adding the second card not only pretty much increase you frame rates from 40 to 100%. It will allow you to run much higher AA and AF settings. Like with my SLI 560 TIs I have the latest Need For Speed Most wanted game for the PC that I play with the Xbox 360 PC controller just for fun. With it being a super duper Console port to the point of there are not many setting's in graphics that you can do to increase the picture quality besides forcing more Anti-Aliasing...besides a single 560ti runs the game with max setting at it's capped 60fps. But with SLI I can force 32x or 64x AA drastically increasing picture quality buy Using one card to render the game and the other card does the AA. Its pretty neat I also use that feature with LFD2....needless to say there are no jaggies

Mr Bensam123,
Your adventure is awaiting you Double the performance possibly for 120 to 140$ on ebay. Possibly one of these cards http://www.ebay.com/bhp/hd-7870
It so happens my Favorite Blower style cooler HIS 7870 model is the cheapest new 7870 at newegg right now at 179$ http://www.newegg.com/Product/Product.a ... 6814161404
Or If you know your 7870 you currently own will clock to 1140 core and 5600 memory this HIS r9 270x Comes clocked at those speeds for 199$ http://www.newegg.com/Product/Product.a ... 6814161442
But I would probably go with the HIS 7870 with that awesome blower cooler. Heck if it runs faster then the 7870 you currently own you could always sell your current card and keep the new one.

This was meant more as a open topic rather then a complete buying decision Vargis.

I agree that a single card is better... but better isn't always cheaper. Comparing $150 to $500 says something in and of itself. I don't have any experience with crossfire or sli so I can't really comment on the niggles. That's one thing that may rub me the wrong way. If it simply doesn't work, I have to turn it off, or if there are undesirable side effects that stack up over time. I am very sensitive to stutter and lag, so if it exists, I'll notice it. I suppose I could always try it and send the card back if the experience is unfavorable.

The 4k resolution crossfire issue and eyefinity stuff doesn't bug me, shouldn't really bug anyone. I'm sure AMD will clean it up in the next few months and I'm sure it'll be a long time before I own a 4k display.

I see double and triple fan coolers, I see more heat blowing around in my case.

From a personal standpoint I'm not after anti-aliasing or anything like that, rather raw higher FPS to go with my 144hz monitor.

I hope TR hops on the bandwagon and starts looking at this stuff, even if it isn't a full blown review. It'd be great to see these 'solutions' where they compete performance wise.

This HIS model I listed has a great blower setup so no extra heat in your case. Its Quiet Cool and a good card. On top of that it is among the most inexpensive models from the egg. If you are looking for raw frame rate it should help a great deal. I do not know if it will hit 144fps? But That is something you will have to play with you never know if a game is running closer to 120fps you might want to turn your refresh rate down to 120 hrtz. Thats the fun of playing with it and tweaking etc.
http://www.newegg.com/Product/Product.a ... 00524&SID=

I could not agree more TR need to do a rehash of the mid range cards in crossfire/SLI with frame time ETC. Even if they just do the Newer 270x 280x and 290x cards when they do the 290 card that has been delayed....of course they have to add the gtx 760. 770 cards in SLI. Since the mid range cards are just rebadges with higher clocks "the GTX760 is a wee bit different then the 670" but it should give a good idea what the original cards will do with frame times etc.

From what I am seeing, my long-time assertion that buying 2 cards at the same time, or very close to each other is the only option that makes sense still. The window used to be within 6-9 months, the past year or so of slower progress increased that to may be 12-18 months. With the new generation of consoles, I think we are due for a more significant bump in GPU requirements for the foreseeable future. So I think the window will be smaller at least going into the first 1-2 years of the new consoles' lifetimes. I would think the 5xx and may be even 6xx (in Nvidia speak, map your own AMD equivalent) generations will not meet the baseline very quick.

So I maintain: buy 1 get another one (much) later is still not a good idea, due to the following (you can think of more):

1. initial acquisition costs
2. power and cooling concerns, which adds to #1
3. we are due for a more meaningful newer generation of GPU tech, which obsolete the current gens quicker

Fox is spot on. There are plenty of reasons to use a multi-GPU setup, but are very specific. Upgrading 'sometime in the future' isn't really one of them.

Personally, I think there are "okay" times to buy a second card, and "terrible" times to buy a second card.

Right now, with both AMD and nvidia, the architecture is the same as before. Newer cards are simply providing more of the exact same GCN/Kepler architecture in terms of clocks/cores/whatever.
If you already have a card with a sensible amount of VRAM on-board, now is an okay time to double up because you're effectively improving something that's still current.

The mistake people make is thinking that two older cards on an outdated architecture is a sensible upgrade path. Assuming AMD and Nvidia are even bothering to optimise last-generation's dual-GPU profiles, the shortfalls of that previous generation are stil not addressed by doubling up on hardware. Whatever it is that is holding back the previous gen card will still hold back two of them.

Why do you see there being a window for buying a extra card? I actually see it as a way of extending a initial purchase. A 7870 was great for me when I first bought it, but now I want more FPS and games are more demanding. Instead of buying a new gen card I can get one more of what I already have that has decreased significantly in price due to the release of a new card. That means my initial investment gains more value and I can extend it longer, as well as it being a good deal $/performance wise compared to new cards. Had I bought two at the same time I would've spent more and there may not have been games around to take advantage of it nearly as much.

I don't think this sort of logic hold once you go back 2-3 generations, but for the last gen that's still readily available on the market it makes sense.

"The mistake people make is thinking that two older cards on an outdated architecture is a sensible upgrade path"

That. Once you reach a certain age it's not worth crossfiring/sling them even if you can get the second card cheap. Second gen is still relatively fresh.

Bensam123 wrote:

Why do you see there being a window for buying a extra card? I actually see it as a way of extending a initial purchase. A 7870 was great for me when I first bought it, but now I want more FPS and games are more demanding. Instead of buying a new gen card I can get one more of what I already have that has decreased significantly in price due to the release of a new card. That means my initial investment gains more value and I can extend it longer, as well as it being a good deal $/performance wise compared to new cards. Had I bought two at the same time I would've spent more and there may not have been games around to take advantage of it nearly as much.

I don't think this sort of logic hold once you go back 2-3 generations, but for the last gen that's still readily available on the market it makes sense.

"The mistake people make is thinking that two older cards on an outdated architecture is a sensible upgrade path"

That. Once you reach a certain age it's not worth crossfiring/sling them even if you can get the second card cheap. Second gen is still relatively fresh.

Which is the mistake the "SLI/CF as a value play" gang makes often. The 7870 is in the "extended" window that I was talking about so it is somewhat of an outlier, because we have been experiencing a slowdown in GPU tech advancement, which can be attributed to the late cycle of the last gen consoles as one reason. The argument makes even more sense when we are talking about midrange, and heaven forbid, lower-midrange GPUs. Take an example of the above 560 example. If I bought a 560 2 years ago, does it make sense trying to buy the 2nd card now? I am not so sure. 550 will be even worse. Also, 2 years ago we may be still be dealing with the Sandy Bridge platform which has advanced quite a bit. Sure, CPU tech is less of an importance for shooter style games, but CPU intensive games you may be feeling some pain (and that includes MMO's, which with unexpectedly large number of objects will stress the GPU as well). Buying a 2nd card after such a long time, especially a midrange of lower one, makes the ROI not as good as buying 2 higher end ones, and/or buying the cards closer to each other.

In the good old days, you won't even find a new card that are 2-3 generations as cheap. The vendors got rid of them fairly quick. As I said, the past 2 years of stagnant advancement is an exception.

Bensam123 wrote:

Once you reach a certain age it's not worth crossfiring/sling them even if you can get the second card cheap. Second gen is still relatively fresh.

I wasn't specifically meaning age, although it correlates reasonably well - I'm talking more about architecture.

Let's say you bought a 6870 a couple of years back; Adding another 6870 after a year or so wouldn't be a great idea even then - because that was when constant improvements were being made to the performance of GCN drivers, frame pacing came along for GCN, the memory manager was completely rewritten. Not to mention game engines were being patched and updated for GCN and Kepler's DX11 compatibility and feature set. VLIW was already dated at that point and doubling up on a dated architecture even though it was capable back then would have been a bad decision.

Now, two years after you were last likely to have bought a 6870 as a "sweet spot" card, you can buy a ridiculously cheap alternatives that are massively superior in many ways:
I saw an HD7850 offer on the front page a couple of days ago for like $90 after MIR - and the lowly 7850 is anything from 25% to 75% faster than the 6870 - the newer the game the bigger the difference. At 75% faster, a cheap $90 bargain would be likely faster and more consistent in modern games than a 6870 XFire setup.
If you want to go mad, the 7950Boost is available in a few places for $215 right now. It's typically 100% faster, sometimes 200% faster than a single 6870.

Whilst I suspect a pair of 7870's to look good in a couple of years, 6870's have been looking pretty dated for half a year already - DX11 is the reason for that, I think.

Which is what I meant by age. "I don't think this sort of logic hold once you go back 2-3 generations, but for the last gen that's still readily available on the market it makes sense."

Curiously Fox, you say buying a second card is a bad value proposition, but don't offer any reasoning as to why. For example I can buy a 7870 for $150 and it almost doubles my performance, which is faster then even a R9-290x.

A 560 is two gens old and wouldn't be a good idea to upgrade as I stated already and Chrispy was pointing at. Now if you had a 660 or a 7870 that'd be a different scenario as they're both freshly second gen... Even if the R9 or 7xx series has been out for awhile, the results will still be relevant.

Bensam123 wrote:

Curiously Fox, you say buying a second card is a bad value proposition, but don't offer any reasoning as to why. For example I can buy a 7870 for $150 and it almost doubles my performance, which is faster then even a R9-290x.

Go back to my other posts in this thread. The context is always "buy one get another one (much) later is a bad idea". It pretty much boils down to knowing what you want and have a realistic plan in an appropriate time frame. Not people thinking about teamng low end cards with a time window of after 2-3 newer generations of CPU and GPU are out (extreme case here, but you get the idea).

Could I piggyback on this thread? Can anyone advise me on a similar situation?

I am running on a 7870 and a Z77 mATX motherboard from earlier this year, which I got a decent deal on. I didn't think I'd ever want CF so of course I got a model that doesn't support x8/x8. It supports x16 3.0 and x4 2.0.

So I screwed myself over a little bit, but if I wanted to upgrade graphics down the road, what would be best?

• Get a new single GPU
• Get a second 7870 and CF it even though it'd be PCIe x4 2.0
• Get a new mobo + 7870

Z77 mobos are becoming cheaper and scarcer :/

I'm currently driving a 1080p display but I have a tiny bit of interest in getting a 1440p one down the road. I want the rest of my components (PSU/CPU/RAM) to stick around until 2016 or so.

Suggestions? Comments?

1. Hold out. The HD7870 isn't nearly slow at 1080p.
2. Upgrade the GPU; do not try to CF on an x16/x4 board. And don't buy any more of those boards .
3. Prepare to upgrade everything, especially if you're not running an overclocked Ivy quad.

I'm in a similar position with Z68- PCIe 2.0 x8/x8 will likely be a limitation for higher-end CF/SLI that would replace my GTX670's, and I'd like to move up to either a Haswell i7 K or an Ivy-E six-core for content creation work, along with a 4k monitor when those become feasible sometime next year. I'm basically resigned to trading out everything, and waiting for stuff like the PCIe SSD sticks to hit motherboards.

Airmantharp wrote:

1. Hold out. The HD7870 isn't nearly slow at 1080p.
2. Upgrade the GPU; do not try to CF on an x16/x4 board. And don't buy any more of those boards .
3. Prepare to upgrade everything, especially if you're not running an overclocked Ivy quad.

I'm in a similar position with Z68- PCIe 2.0 x8/x8 will likely be a limitation for higher-end CF/SLI that would replace my GTX670's, and I'd like to move up to either a Haswell i7 K or an Ivy-E six-core for content creation work, along with a 4k monitor when those become feasible sometime next year. I'm basically resigned to trading out everything, and waiting for stuff like the PCIe SSD sticks to hit motherboards.

I have a 3770k there waiting to be overclocked as soon as I feel like it. The 7870 runs everything on high usually at 1080p, but at 1440p it will be another adventure. My point is I don't know whether a new single GPU down the road is worth it, or a new Z77 x8/x8 motherboard + 2nd 7870 would be a better investment.

New single-GPU down the road, when you get your 1440p display.

Airmantharp wrote:

New single-GPU down the road, when you get your 1440p display.

Thanks! I look forward to the post-28nm flagships.

Duct Tape Dude wrote:

Airmantharp wrote:

New single-GPU down the road, when you get your 1440p display.

Thanks! I look forward to the post-28nm flagships.

Same here .

Crossfire remains a bad idea at this time.

Still no DirectX 9 or older support, OpenGL support, EyeFinity support, or 4K support (barring the new 290 series apparently).

EyeFinity pixel counts that exceed 4m will remain a problem so long as the older generation lacks XMDA. Keep in mind that 5760x1080 is 6m pixels.

I see the lacks of older DirectX support as an issue as well. Publishers are really starting to realize the value of their older intellectual properties. It's part of why GoG is so successful and even Steam is starting to see old titles published. One of my favorite ancient games is System Shock 2 (DirectX 6) and it works with SLI and can be leveraged to apply vast quantities of post processing (16x CSAA for example). The newer 2.40 release of System Shock 2 (DirectX 9) even allows for silly adjustments like fp16 or fp32.

http://steamcommunity.com/sharedfiles/f ... =100103594

Crossfire still has a long way to go from a support perspective. This doesn't even delve into the great arguments above about the money and timeframe aspects of this technology. For 1080p and a card that's already twenty months old it just doesn't make good sense.

My personal rule of thumb has always been, if 2x the card I have now is less than or equal to the performance of the second highest performing card of the time, SLI/CFX isn't worth it. It's almost always better to sell and buy new at that point.

Still some selling (7870) at $130, saw one yesterday on Newegg for $115. I hope TR eventually does a article one this (including Sli). There are some pretty meaty deals right now, especially if you're looking for performance in line with a top of the line graphics card (or better). I'd definitely like to know what TR is thinking on this. Hypothesizing only does so much.

Anyone know of any reviews that look at things from this angle? I'd be interested in those as well.