Also, we say ASUS has joined this market, but of course the company has a proud tradition of building extremely limited-edition bonkers insane dual-GPU super cards For the very rich, and very persistent: there are only 999 ARES Ils, so good luck finding on! As mentioned, PowerColor was the first vendor to market with a dual-Tahiti monster; it was called the Devil 13. There are a few key differences in the two cards, however, most of which are patently obvious when you first open the box and gaze upon the beauty that lays inside.
SPECS
- 2x HD 7970 (Tahiti) Cores @ 1050Hz
- 6GB DDR5 RA @ 1650Hz
- 4x DisplayPorts
- 2x DVI Ports
- Dual Slot active cooling with external 120mm radiator
ASUS has lovingly custom-designed a water cooling solution (as opposed to a triple-slot colossus) to cool both of the GHz Edition HD 7970 cores, while employing a fairly standard cooling fan on the card in order to cool down the PWM, and any other vulnerable hardware, with passive airflow. Think dual Corsair H60 CPU cooler mounts (although these are made by Asetek) for the GPU cores, and then smack a rather chunky dual-slot heatsink dedicated to PCB cooling on top, and you're somewhere close to the extreme design ASUS has engineered.
As for the cooling radiator itself, it comes fitted with a single fan by default, though ASUS has included a second fan for a push/pull configuration if you so choose. The radiator also has an integrated pump, much like the Corsair H60 CPU cooler. If you do plan on using this card for anything other than display purposes in a trophy cabinet, then you will need to find somewhere within your case that has a good 80mm of clearance in order to mount the radiator. For this reason, the card will almost certainly work better in a case that is already using a compact CPU water cooler; otherwise, the cooling tower on large air coolers may take up too much room in your conventional ATX tower.
The key difference between the ASUS iteration of the HD 7990 and what PowerColor chose to employ with the Devil 13 doesn't just end with the cooling. The PCB design here is lavish, to say the least, featuring no fewer than 20 Power Phases; 16 for the GPUs (8 each) and four for RAM (2 each). This is pure overkill, but then again so is the entire idea of this video card to begin with!
The Tahiti cores have been clocked a little higher than the standard GI-4z Edition specification, coming in at 1050MHz as a base clock and featuring a rather potent 1100MHz as the boost. This is enough to see the ARES II comfortably squash the GTX 690 and even most traditional HD7970 CrossFire solutions — something not often seen from a single card.
POWER UP
When overclocking, don't be surprised if you hit some snags at the typical 1,200-1,300MHz frequency. Despite the ARES ll's extravagant PCB design, there comes a point where you simply can't put any more current through the cores than the OCP protection will allow, and for this reason we won't be able to proceed much further without firing up the soldering iron and modifying the PCB.
However, considering this card is the only review sample in the country, and with that 999 card run from ASUS worldwide, we decided that cracking out the soldering iron would likely be frowned upon (ASUS still hasn't forgiven us for pushing the review sample of the $1,600 MARS II card so far that it melted, back in PCPP#197) so we decided to see how far the ARES II can go on stock cooling.
The card uses two CHiL voltage controllers, which have been used in the past by ASUS on its high-end GPUs These ones have been rebranded with the Digi+ logo and are used for independent control over the GPU core voltages, allowing PC gamers with advanced software to individually control the voltage on each GPU core.
We managed to achieve a core clock of 1,245MHz across both cores. When taking individual control over the cores, our first core managed to push a little further to 1,255MHz. Obviously, these clocks are not guaranteed should you be lucky enough to find an ARES II in the wild, nor should the card be subjected to these settings for more than a few hours of overclocking as the heat, power consumption and noise are not healthy for any party involved.
In terms of performance gains, Tahiti actually scales very well with core clocks. It isn't until we hit 1,400MHz+ on LN2 that we typically saw large diminishing returns on clock scaling. We didn't run our full benchmark suite at the 1,245MHz clocks because, again, we quite like to melt things, and it's polite to return such a rare beast in working condition. We did, however, run 3DMark 11 while overclocked at 1,255MHz+1,245MHz and managed to earn ourselves a nice score of 16243. Plus, we may have received a healthy 20% increase in our Battlefield 3 frame rates — though, not that the game needed it in The Bunker's rig.
Now, on to the memory overclockingl This is one of the areas where you can really luck out on the videocard lottery. We've seen more than a few cards that struggle to operate at much beyond the stock memory clocks. We did seem to find at least a half decent card here, with the ARES II going strong and reaching 1,850MHz across both memory clusters. This is to be expected when dealing with such a large memory pool; if any of the 18 memory blocks soldered to this card can't keep up with the others you'll get instabilities and crashing. There will no doubt be cards capable of breaking 1,900MHz, though to be honest with a 384-Bit bus you don't really need much more from your RAM, even when overclocking and benchmarking at massive resolutions.
HOT STUFF
Now for the part you've have been waiting for. Sure, the ARES II is fast, but how hot is that thing going to be? It's not like everyone's Bunker is equipped with nuclear coolant, so how do I stop my own ARES II from going radioactive and fusing with the motherboard?
Surprisingly, the card is not actually all that hot. The water pump does a pretty good job of quickly drawing heat away from the main source (the GPUs), while the dedicated heatsink and fan does its best to keep the memory and on-board components as cool as possible. In our testing, we recorded temperatures of only 58C under load when using a single fan, which we pushed down to a chilly 55C when we employed the second 120mm fan onto the radiator.
Idle temperatures were as low as 26C while sitting in our "silent" system, which consists of three Fractal Design fans and a Fractal Design Define Mini tower — not your typical testbench, though it does represent your typical PC tower at home and the level of airflow they provide. The ambient temperature inside The Bunker is engineered to maintain a comfortable 24C, as well as to keep all light (and test subjects) from escaping.
When we kicked the card into gear and began overclocking, the temperatures obviously did increase. We saw the card hit 66C at one point, so let's say that is the peak temperature you should ever see on the ARES II. That's not at all bad when you consider previous generations of dual-CPU cards typically pushed the high 90s and even reached boiling point (which would be catastrophic in a water cooling configuration like on the ARES II).
Overall, we're delighted with the thermals of this card. Even dipping our thermometer Into the nooks and crannies of the ARES II itself revealed very low PCB temperatures when compared with some competitors, reading as low as 45C in parts with the maximum reading of 58C. Again, this is more than acceptable, and we do take our hats off to ASUS for taking the time to think about how to improve the ARES over previous designs.
THE SOUND OF SILENCE
So we have a pretty cool card here — but does it remain quiet? The short answer here is yes, but how can the ARES II be so quiet, despite being so powerful? Not only does water cooling extract heat more efficiently than air, giving the ARES II an instant advantage over traditionally cooled cards, the secret lies in splitting up the cooling workload.
Removing GPU heat to a separate 120mm radiator, while leaving PCB cooling to a traditional heatsink and fan combo, is nothing short of revolutionary (despite obvious space requirement issues). Even if these fans were loud (they aren't!) we'd be happy with this solution due to its efficiency. But our decibel reader will be the ultimate judge.
With a reading taken from 100cm, we recorded a level of 26dbA (with a single radiator fan), which, for those not in the know, is pretty damn good. By comparison, our GM 680 is a quiet model — a Gigabyte Windforce X3 edition — which managed to record a decibel level of 29dbA. This means that in average circumstances the ARES II should be no noisier than your typical high end gaming system, and if you're actually concerned about noise can be made much quieter.
We did get a 3dbA increase when we installed the second radiator fan, though that's nothing of concern. With these thermal results, we'd be happy to install a pair of Noctuas onto the radiator and call the system silent.
COMING OUT ON TOP
The key difference between the ARES II and other luxury, limited release cards is this one is at least partially justified in its asking price. ASUS has expressed the ability to employ real R&D teams and come up with a product that is not only different to what the competition is offering — it's also superior.
Not only has this card got all of the benefits of a dual-GPU PCB, it has very few of the negatives. Assuming you can fit this monster in your PC, and you have a spare mounting position for the radiator, you'll have a card that actually represents something different to all others on the market — even the Devil 13.
It's not a gimmick; the design actually works and there are benefits to installing the ARES II into your dream system. This card will run just as well in a mini tower as it will a Silverstone T.111. For those who can afford it without defaulting on their rent, the ARES II is worth your consideration.
PROS
- Truly Superior dual-GPU design
- Luxury custom water cooling
CONS
- The cooling solution won't be for everyone
- Memory overlocking varies from card to card
http://www.asus.com/ROG/ARES26GD5/
