ASUS Matrix Radeon HD 7970 3GB Overclocked Graphics Card Review
A ton of technology in here
In the world of graphics cards there a lot of also-rans, cards that were released but didn't really leave a mark on the industry. Reference cards are a dime a dozen (not really, though $0.10 HD 7970s sounds like a great thing to me) and when the only thing vendors can compete on is price it is very hard to make a compelling argument for one card over another. The ASUS Matrix Platinum HD 7970 that we are looking at today in no way suffers from these problems - it is a custom design with unique features that really give it the ability to stand out from the clogged quarters of the GPU shelf.
As you should expect by now with the ASUS ROG brand, the Matrix HD 7970 not only has a slightly overclocked clock speed on the GPU and memory but also some unique features like VGA Hotwire, TweakIt buttons and more!
ASUS ROG Matrix Design
Before we dive into performance and our experiences in overclocknig the HD 7970 with the ASUS Matrix Platinum we wanted to go over some of the design highlights that make this graphics card unique. Available in both Matrix and Matrix Platinum (hand picked chips) revisions, this triple-slot design will include a custom built PCB with 20-phase power and quite a bit more.
This "exploded" view of the Matrix HD 7970 shows a high-level view of these features with details to follow below. Some of the features are really aimed at the extreme overclockers that like to get their hands into some LN2 but there is still a lot to offer users that just want to try their hand at getting additional performance through air overclocking.
ASUS' custom DirectCU II cooler is at work on the ASUS Matrix HD 7970 using all copper heatpipes to help lower temps by 20% compared to the reference HD 7970 while also running quieter thanks to the larger 100mm fans. These fans can be independently controlled and include the ASUS dust proof fan technology we have seen previously.
In many cases, the changes that ASUS has made on the Matrix can't really be seen by users that purchase it - such is the case with the improvements in the power delivery system on the Matrix HD 7970. The power plane on the card is what provides the juice to the GPU and memory and increasing the physical size can have benefits like less variance in PCB depth and less voltage drop between phase changes. The Matrix card includes a 56% larger power plane than the reference HD 7970 PCB with 65% less voltage drop which should translate into a cooler running GPU.
ASUS has included a DIGI+ VRM configuration with 20 power phases and super alloy power chokes, capacitors and MOSFETs. Japanese black metallic caps are rated at higher (and lower) temperature ranges and longer lifespans that standard solid caps giving them a range of -70C to +125C as well as a 10,000 hour life compared to ASUS of DirectCU II design of 5,000 hours and many other cards at 2,000 hours.
The 20 phase power delivery system leaves room for "experimental performance tuning" according to ASUS which basically translates into good news for the LN2 crowd.
Other overclocking features on the Matrix HD 7970 include VGA Hotwire, the capability to attach leads from your graphics card to one of few specialized motherboards (without the need for soldering) from ASUS to directly control voltages via the UEFI and overclocking software. Currently that feature is limited to users of the Rampage IV Extreme and Maximus V Extreme boards.
The TweakIt buttons allow overclockers to adjust real-time hardware level voltage with an LED indicator for your current level. This is useful for open-system testing and when you think you might be getting into an unstable situation. This can actually let the Matrix card go ABOVE 1.4v with each press representing a 6.25 mV stepping.
Similarly, the Turbo Fan button, when depressed, will push both of the 100mm fans to spin up to 100% to quickly lower temperatures. Obviously that means a dramatic increase in noise as well.
Finally, the Safe Mode button performs a similar function to a Clear CMOS button by reverting the graphics card back to stock and stable settings if your overclocking gets out of hand.
For those users that want even more control, the ProbeIt section on the back of the card allows for some very specific functionality like monitoring voltages directly, disabling the GPU over voltage protection and manual voltage modifications.
One feature that is mostly for show is the load level indicator LED on the top of the card that changes colors as the GPU load level changes. Green for idle, blue for medium load, red for the highest GPU usage. It changes as you game and during stressful times in a game and you can see it in action in our video segment above.
Also, with a pair of dual-link DVI connections and four full-size DisplayPort connections, the ASUS Matrix HD 7970 can support six (not four as reported in the video, sorry!) monitors for those of you interested in Eyefinity 6 gaming! There is one thing to keep in mind though; there is a switch along the top of the Matrix card near the CrossFire connector that will make one of the DVI connections single link (1920x1200 max resolution) and enable all 6 outputs OR make both DVI connections dual link and disable the 4th DP connection.
Finally, with the ASUS Matrix card you'll get a custom version of the ASUS GPU Tweak software that includes impressive capability for overclocking including clock speeds of the GPU and memory, overvolting, loadline calibration and VRM frequency. That is the type of control you won't get with any other card/software combination and it is in fact the first time anyone has implemented LLC and VRM frequency adjustment on a graphics card. In order to implment that ASUS had to embed a custom controller IC so it will only be found on the Matrix HD 7970 for the time being.