Creating the Juggernaut - ATI Radeon HD 5870 CrossFireX Analysis

The Apex of Graphics Performance

ATI has just launched the Radeon 5800 series to mostly positive reception. With no serious competition in sight from NVIDIA till possibly early next year, the onslaught from the red team is just beginning. We've received word that the 5700 series (known as Juniper) is being prepped for release as we speak and we'll be bringing you its performance numbers really soon.

We've as the world's fastest single GPU. The chip, codenamed "Cypress XT", boasts a mind boggling 2.15 billion transistors and 1600 stream processors running at 850MHz, which is then further aided by 1GB of super-quick GDDR5 memory running at 4.4GHz DDR, making it a bona fide juggernaut amongst graphics cards.

On the horizon too is ATI's dual-GPU giant, the Radeon HD 5870 X2, otherwise known as Hemlock. The 5870 X2 model will follow in the tradition of the 4870 X2 and the 3870 X2, by combining two Radeon HD 5870 GPUs on a single PCB. With it, ATI hopes to reclaim the title of the world's fastest single graphics card from NVIDIA's GeForce GTX 295.

Sadly, the Hemlock is not with us yet today, but we will attempt to simulate one by having two Radeon HD 5870 cards in CrossFireX configuration - courtesy of ASUS and PowerColor whose cards and bundle information are highlighted in the following page. We expect performance to improve of course with two of these monster cards, but also equally important is the amount of scaling going from one to two GPUs, the power consumption figures and thermal considerations, if any.

Additionally, we'll be doing our tests a little differently this time. What we will do is to run our usual benchmarks benchmarks on two setups, one of which is our older Intel X38 system and another with a Core i7 on an Intel X58 motherboard.

Given the tremendous graphics crunching power of the Radeon HD 5870, we are curious to see if our older Intel X38 system is capable of keeping up with the cards, or if you'll need an equally high-end system to enjoy the full performance of two Radeon HD 5870 cards. After all, we've already established in our previous review that dual Radeon HD 4890 cards or a GTX 295 poses no performance penalty when run on our current Intel X38 based graphics testbed, so it will be interesting to see the differences this time round.

The ASUS EAH5870

The ASUS EAH5870 looks just like any other Radeon HD 5870 card on the market right now and it is also specced similarly, which means it is clocked 850MHz at the core and 4400MHz DDR at the memory. However, it differentiates itself from the competition by offering voltage tweaking via its SmartDoctor utility.

SmartDoctor is ASUS' usual overclocking software that allows you to tweak the card's settings, like clock and fan speeds while monitoring the temperature. The one with the ASUS EAH5870 adds in Vcore voltage tweaking, potentially allowing you to achieve higher clock speeds at the core, and stretching your overclocking experience. As a plus, the ASUS EAH5870 also allows you to redeem a downloadable copy of Dirt 2, one of the first games to officially support DirectX 11 when it comes out for the PC later this December.

The PowerColor HD 5870

The PowerColor HD 5870 is your no-frills Radeon HD 5870, which we previously featured for our first Radeon HD 5870 review. The card doesn't come with any special bundled software or games unlike the ASUS card, and comes with reference clock speeds and ATI's redesigned stock cooler. It's a simple package for those who demand nothing but the absolute fastest graphics card, nothing more, nothing less.

Test Setup

We'll be using two system configurations to evaluate the Radeon HD 5870 in CrossFire, one of which is our trusty Intel X38 setup, which has the following specifications:

• Intel X38 Test System:
• Intel Core 2 Extreme QX6850 (3.00GHz)
• Gigabyte X38T-DQ6 motherboard
• 2 x 1GB DDR3-1333 Aeneon memory in dual channel mode
• Seagate 7200.10 200GB SATA hard drive
• Windows Vista Ultimate with SP1

To see if the Intel X38 still has what it takes, we've also benchmarked the cards on an Intel X58 system with the following specifications:

• Intel X58 Test System:
• Intel Core i7 975 (3.33GHz)
• Gigabyte GA-EX58 Extreme motherboard
• 3 x 1GB Kingston HyperX DDR3-1333 in triple channel mode
• Seagate 7200.10 200GB SATA hard drive
• Windows Vista Ultimate with SP1

Key comparisons here will obviously be between the CrossFire setups with the Radeon HD 5870 and the Radeon HD 4870 X2. We are also interested to see how the performance varied across the Intel X38 and X58 platforms. The X58 may have the brawn of Intel's current flagship Core i7 processor, the Core i7 975, but gaming performance is still heavily dependent on GPUs rather than CPUs. With that in mind, let's examine the variance in performance on the two platforms.

The full list of cards and driver versions used:

• ATI Radeon HD 5870 1GB GDDR5 (ATI Driver 8.66 Beta)
• ATI Radeon HD 5870 1GB GDDR5 in CrossFireX (ATI Driver 8.66 Beta)
• ATI Radeon HD 4870 X2 2GB GDDR5 (Catalyst 9.8)
• ATI Radeon HD 4870 X2 in CrossFireX 2GB GDDR5 (Catalyst 9.8)
• NVIDIA GeForce GTX 295 1792MB GDDR3 (ForceWare 190.62)
• NVIDIA GeForce GTX 285 1GB GDDR3 (ForceWare 190.62)

The cards were tested using the following benchmarks:

• Futuremark 3DMark06
• Futuremark 3DMark Vantage
• Crysis Warhead
• Far Cry 2
• Warhammer: Dawn of War 2

3DMark06 Results

We begin, as we usually do, with 3DMark06. The benchmark might be a little old, but it is still used widely to gain a rough gauge of a card's performance. Immediately, we noticed that two multi-GPU setups performed very similarly. Their scores were nearly identical, especially on the X38 system.

3DMark Vantage Results

It was a similar story on Vantage too, with both the pair of Radeon HD 5870s and HD 4870 X2s performing closely. It was only on the Extreme preset that the pair of HD 5870 managed to edge out a substantial lead. Still, you've to remember that the two new GPUs (5870) are matching or bettering the four older GPUs (4870) and that speaks volumes for the newcomer's raw power.

Crysis Warhead & Far Cry 2 Results

The pair of Radeon HD 5870 and HD 4870 X2 cards have been closely matched thus far, with the newer HD 5870 taking a slight lead on higher, more demanding settings; will it maintain or better its performance advantage on real world gaming applications? Read on.

On Crysis Warhead, the pair of Radeon HD 4870 X2 cards was the best performer by far. Managing an incredible 51fps even on the the most demanding setting of 1920 x 1440 with 4x anti-aliasing enabled. But the pair of Radeon HD 5870 cards isn't far behind at all though. The superb performance of the HD 4870 X2 cards is most likely due to the fact that it has a whopping 4GB of frame buffer, as opposed to the HD 5870 cards combined frame buffer of 2GB. To give you some perspective of the matter at hand, a single Radon HD 4870 X2 is slower than a single GeForce GTX 295, so the only logical reason for the CrossFire pair of the 4870 X2 to fair better is more frame buffer in addition to four GPUs to pick up the slack.

On Far Cry 2, the two sets of cards were again closely matched. Despite its larger framebuffer, we noted performance of the pair of Radeon HD 4870 X2 faded gradually as we upped the settings. Remember that the Radeon HD 5870 are running on new drivers, albeit in beta, and it is likely that these new drivers are more optimized for Far Cry 2, thus leading to what we see here.

Dawn of War 2 Results

On Dawn of War 2, Warhammer 40,000 fans will find greater joy with a pair Radeon HD 5870 as it consistently outperforms the Radeon HD 4870 X2. In fact, on the X38 setup, a single HD 5870 recorded better results than the pair of HD 4870 X2. Our experiences with Dawn of War 2 tells us that the game has scaling issues and this is probably why the pair of HD 4870 X2 performed as they did. This serves to remind us that the benefits from CrossFireX don't always scale proportionately and much is dependent on both the game and driver optimization.

Temperature

One of the biggest concerns with running multi-GPU configurations is the heat they produced, and it is indeed something a user should look into. During our tests, the systems hung quite frequently in the early morning when air-conditioning in our offices wasn't yet turned on and our labs were still warm and stuffy. The Radeon HD 4870 X2 especially, were incredibly hot to touch, and the despite the cooling efforts of the Storm Sniper casing.

It certainly seemed as if the heat was too much to take, causing it to hang a couple of times. So many a times, we just waited till the air-con kicked in when official work hours begins. Of course, we always conduct temperature testing when our office air-con is in full force and the temperatures have stabilized, but the above are just our notes to relate to you on how picky such multi-GPU setups can be if ventilation and temperature is poor.

According to GPU-Z, the pair of Radeon HD 4870 X2 cards recorded a staggering 90 degrees Celsius on both cards, and it certainly felt like it. The Radeon HD 5870 fared better, clocking a lower 80 degrees Celsius temperature per core.

Power Consumption

Power requirement is another crucial aspect that users should not overlook. The Radeon HD 5870 has rather modest power requirements, comparable to that of other high-end cards, and so a PSU rated for 600W would suffice for a two-way CrossFireX configuration. The Radeon HD 4870 X2, however, is not so easily appeased, and ATI has stated that a PSU rated for a whopping 1000W is needed for two HD 4870 X2 cards to work in tandem.

From our graphs, we can clearly see the monstrous power requirements of the Radeon HD 4870 X2 CrossFireX pair. Peaking at nearly 700W, its power requirement is nearly double that of the Radeon HD 5870 CrossFireX pair. Furthermore, when measuring the power draw of the Radeon HD 4870 X2 pair, we noticed that the power draw was prone to wild fluctuations, sometimes surging as high as 770-plus watts. A formidable PSU is a must for a HD 4870 X2 CrossFireX setup and thankfully such a requirement isn't necessary on the new Radeon HD 5870 cards.

Intel X38 vs. Intel X58 Results

Given that the two synthetic benchmarks take into account CPU performance when tabulating scores, we were not surprised to see the X58 system using our top Core i7 processor scoring substantially higher on both 3DMark06 and 3DMark Vantage.

On gaming applications too, we noted that you can gain significantly more performance on an up to date X58 system. As the graphs clearly show, on both Far Cry 2 and Dawn of War 2, performance gain on an X58 system on average was around 30% to 40% - and that's quite a significant amount. The only time when the might of the Core i7 processor did not come into play was on Crysis Warhead.

So clearly, whether or not an X58 platform is useful or not depends on whether the software in question can successfully take advantage of the Core i7's added might over an older architecture such as the Core 2 Quad processor on our Intel X38 system.

Time to Upgrade

From our results, we can see that two Radeon HD 5870 cards can work as well, if not better than two Radeon HD 4870 X2 cards. Bearing in mind that a single 4870 X2 boasts dual 4870 chips, this is in fact not a fair match at all - four GPUs on two Radeon HD 4870 X2 cards versus two GPUs on the pair of Radeon HD 5870. This is a testament to the sheer might of the new Cypress XT chip.

Overall, there is little to separate the two cards. Across most of the benchmarks, both multi-GPU setups produced comparable, if not identical, scores. So as far as outright performance is concerned, it is a stalemate.

Elsewhere, however, there's much to suggest that a dual Radeon HD 5870 setup is the more feasible one. First of which is availability and pricing. Radeon HD 4870 X2 have been pretty rare of late, which is no surprise given that the original Radeon HD 4870, whose chips it uses, has been superseded by the newer Radeon HD 4890. And even if you were lucky enough to find a Radeon HD 4870 X2, price is in the same ballpark as that of the cutting-edge Radoen HD 5870. In such instances, there is no reason why anyone would pick the HD 4870 X2 over the newer HD 5870.

Other considerations such as thermal and power requirements also put the Radeon HD 5870 at an advantage. The older RV770 chips were infamous for being hot, so imagine having not one, not two, but four in your system. As our experience tells us, the internals of the casing becomes unbearably warm, even in a casing as free-flowing as the from Cooler Master. Of course that is not to say that HD 5870 wasn't warm, but it was significantly less so than the two Radeon HD 4870 X2 cards.

The insane power requirement of the Radeon HD 4870 X2 pair also puts it at a severe disadvantage. As shown in our setup, a pair of Radeon HD 4870 X2 requires nearly twice as much power to operate compared to a Radeon HD 5870 CrossFireX setup. Therefore, where performance per watt ratio is concerned, the newcomer easily trumps everything else (for the moment at least).

What about performance comparisons across the X38 and X58 setups? Well, it would seem that our Intel X38 system with the Core 2 Quad is showing its limitations. Discounting the synthetic benchmarks which normally scale with CPU power, tests on Far Cry 2 and Dawn of War 2 have shown that performance on a new Intel X58 setup with its powerful Core i7 processor is noticeably faster.

Interestingly, Anandtech did a comparison with on the Radeon HD 5870 in CrossFireX on both P55 and X58 to find out if there's any difference, and the tests suggest that while the X58 is noticeably quicker, the difference is only a paltry 2% to 7%. Where our tests are concerned using a different comparison scale of an X38 and X58 systems, we saw some huge gains on the X58 system especially on Far Cry 2 and Dawn of War 2. And as developers begin to optimize games for the new generation of Intel processors, we think that the older Core 2 processors will no longer be sufficient. If your intent is to get the upcoming Radeon HD 5870 X2, you'll definitely need an Intel X58 setup with a high speed Core i7 processor to stretch it to its limits.

In summary, our tests have demonstrated the potential of the upcoming Radeon HD 5870 X2, and have shown that you'll need a modern high-end system preferably using a high speed Core i7 processor to fully enjoy and extract the power that two Radeon HD 5870 cards in CrossFireX can provide. The upcoming HD 5870 X2 should be a real cracker and if ATI can do more to keep the HD 5870 X2's power consumption and operating temperatures lower than what we've seen here, all the better. So keep your fingers crossed for it in the coming weeks ahead.

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