AMD's Radeon HD 4870 X2 - Testing the Multi-GPU Waters
by Anand Lal Shimpi & Derek Wilson on August 12, 2008 12:00 AM EST- Posted in
- GPUs
Final Words
I've never felt totally comfortable with single-card multi-GPU solutions. While AMD reached new levels of seamless integration with the Radeon HD 3870 X2, there was always the concern that the performance of your X2 would either be chart topping or merely midrange depending on how good AMD's driver team was that month. The same is true for NVIDIA GPUs, most games we test have working SLI profiles but there's always the concern that one won't. It's not such a big deal for us benchmarking, but it is a big deal if you've just plopped down a few hundred dollars and expect top performance across the board.
Perhaps I'm being too paranoid, but the CrossFire Sideport issue highlighted an important, um, issue for me. I keep getting the impression that multi-GPU is great for marketing but not particularly important when it comes to actually investing R&D dollars into design. With every generation, especially from AMD, I expect to see a much more seamless use of multiple GPUs, but instead we're given the same old solution - we rely on software profiles to ensure that multiple GPUs work well in a system rather than having a hardware solution where two GPUs truly appear, behave and act as one to the software. Maybe it's not in the consumer's best interest for the people making the GPUs to be the same people making the chipsets, it's too easy to try and use multi-GPU setups to sell more chipsets when the focus should really be on making multiple GPUs more attractive across the board, and just...work. But I digress.
The Radeon HD 4870 X2 is good, it continues to be the world's fastest single card solution, provided that you're running a game with CrossFire support. AMD's CF support has been quite good in our testing, scaling well in all but Assassin's Creed. Of course, that one is a doubly bitter pill for AMD when combined with the removal of DX10.1 support in the latest patch (which we did test with here). That has nothing to do with CrossFire support of course, but the lack of scaling and the fact that 4xAA has the potential to be free on AMD hardware but isn't really doesn't stack up well in that test.
In addition to being the fastest single card solution, the 4870 X2 in CrossFire is also the fastest 2 card solution at 2560x1600 in every test we ran but one (once again, Assassin's Creed). It is very important to note that 4-way CrossFire was not the fastest solution at lower than 2560x1600 in as many cases. This is generally because there is more overhead associated with 4-way CrossFire which can become the major bottle neck in performance at lower resolution. It isn't that the 4870 X2 in CrossFire is unplayable at lower resolutions, it's just a waste of money.
We do have yet to test 3-way SLI with the newest generation of NVIDIA hardware, and the 3-way GTX 260 may indeed give 2x 4870 X2 cards a run for their money. We also have no doubt that a 3x GTX 280 solution is going to be the highest performing option available (though we lament the fact that anyone would waste so much money on so much unnecessary (at this point in time) power).
For now, AMD and NVIDIA have really put it all in on this generation of hardware. AMD may not have the fastest single GPU, but they have done a good job of really shaking up NVIDIA's initial strategy and forcing them to adapt their pricing to keep up. Right now, the consumer can't go wrong with a current generation solution for less than $300 in either the GTX 260 or the HD 4870. These cards compete really well with each other and gamers will really have to pay attention to which titles they desire greater performance in before they buy.
The GTX 280 is much more reasonable at $450, but you are still paying a premium for the fastest single GPU solution available. In spite of the fact that the price is 150+% of the GTX 260 and the 4870, you just don't get that return in performance. It is faster than the GTX 260, and most of the time it is faster than the 4870 (though there are times when AMD's $300 part outperforms NVIDIA's $450 part). The bottom line is that if you want performance at a level above the $300 price point in this generation, you're going to get less performance per dollar.
When you start pushing up over $450 and into multi-GPU solutions, you do have to be prepared for even more diminished returns on your investment, and the 4870 X2 is no exception. Though it scales well in most cases and leads the pack in terms of single card performance when it scales, there is no gaurantee that scaling will be there, let alone good, in every game you want to play. AMD is putting a lot into this, and you can expect us to keep pushing them to get performance impovements as near to linear as possible with multi-GPU solutions. But until we have shared framebuffers and real cooperation on rendering frames from a multi-GPU solution we just aren't going to see the kind of robust, consistent results most people will expect when spending over $550+ on graphics hardware.
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M1KEO - Saturday, August 16, 2008 - link
Buying a high end video card has little to no effect on the price of gasoline, seeing as very few power plants run off of oil. And are you relating electicity usage to forest fires and floods which are all natural disasters, and have been happening for milleniums? Look at what scientists are saying, and realize temperatures were actually warmer in the 1980's then they are now, and that plants even flourish with more CO2 in the atmosphere because that is what they use to make oxygen.far327 - Sunday, August 17, 2008 - link
Whatever makes you sleep better at night. Your approach is as if energy, despite how it is produced or distributed is an endless commodity. Where as, I am trying to take a more conservative approach towards the ideal that energy is a valuable resource because of the ways we import it and produce it. Now if energy was made via solar or wind, I would loosen up a bit with my energy spending habits because that it would then be renewable energy. I'm just saying, don't feed the pig if it's already over weight. Eventually that pig will not be able to walk, and the meat with spoil. We as a country need to completely change the way we think about our energy spending habits. If we buy these power hog cards and create a viable market for Nvidia and AMD to invest in year after year. The exuberant careless energy spending cycle continues... We are therefore feeding that pig until it will eventually collapse. WAKE UP AND SMELL THE NEWS PEOPLE!! Global warming is not even debatable anymore! It is a very real threat towards our existence as a people. I am done with this childish debate and I'm sure all of you will be happy I leave the board, but don't say you weren't all warned.BenPope - Thursday, August 14, 2008 - link
I guess SidePort will become useful on 4-way plus... in much the same way as 2 or more hypertransport links in opteron 4 and 8 way CPUs scale.So if you have 4 GPUs, the sideports could connect diagonal corners to reduce latency the two-hop latency and increase bandwidth.
Barack Obama - Thursday, August 14, 2008 - link
:)oldhoss - Thursday, August 14, 2008 - link
Uh oh...Bedwetting tree huggin liberal alert! ;-PHrel - Thursday, August 14, 2008 - link
How the heck did you not include the 9800GX2 in your testing; I mean, that's Nvidia's only comprable card. And you said yourself it outperforms the GTX 280. When you factor in that it only cost 285 dollars on newegg it's a great buy. I'm actually amazed and sincerely confused as to why that card wasn't included in this review. Big mistake anandtech; not a small oversight but a complete disregard for common sense.jeffrey - Thursday, August 14, 2008 - link
Usually, NDA dates are known well in advance for the latest and greatest tech. That means that many people are excited and looking forward to insight on release day.I was happy to see the 4870 X2 posted when I opened the site. I was even happier to see the authors of the review were Anand and Derek. This to me usually means a well-thought out unbiased article that would have unique industry insights.
The article seemed rushed, incomplete, and unbalanced. What a disappointment! ATI released the current performance king in the 4870 X2, a mid-level 4850 X2, AND refreshed the 4870 and 4850 by doubling the RAM!
So much time and effort was wasted in the article whining about AMD/ATI not using the Sideport that driver versions and system specs weren't even included.
This post probably sounds like a broken record now that I'm number 70 something giving feedback that is not very positive. I just want this site to stay the best and I felt I owed it to you Anand and Derek to try and push you to do better. Thanks for all the great work that you have done over the years.
Bezado11 - Wednesday, August 13, 2008 - link
I loved the article and well it shows that the new king of cards is the 4870X2, however; I think your doing a bit of extra work for a benchmark nobody will use. AOC is tanking hard, not sure if you guys are aware of that games overall lack of integrity. Since AOC is not going to be a well played or viewed game, why use that as a benchmark standard? I mean we won't care one bit about it sooner or later because the game is in it's death stages.Just a heads up on that. I think taking the AOC benchmark out of future reviews will be advised. Stick to what we know best and what stresses the hardware the most like Crysis etc. AOC for heavens sake doesn't even support DX10 yet.
Griswold - Thursday, August 14, 2008 - link
While I dont play AoC or plan on doing so, you just showed what a foolish idiot you are by claiming its soon demise. It has been the fastest selling MMO launch in history, I think "some" people will stick to it and even more will return when the content problem has been solved. Just because you dont like it, doesnt mean its not a good benchmark.I mean, I couldnt care less about all these "quake wars" and "ssassins creeds" that are, in my opinion, played by dumbass kids such as you, but hell, I wont complain about them being used as a benchmark.
Scour - Wednesday, August 13, 2008 - link
This article is a way to negative for AMD/ATIs cards. This looks like the reviewer hate ATI, dunno whyFirst the negative article about 790GX-chipset, now this :(