Introduction
Nvidia's Maxwell-powered GeForce GTX 980 and GTX 970 GPUs came blowing into town last week. Characterised by class-leading performance and exceptional energy efficiency, the GTX 980 lays solid claim to being the most advanced, fastest GPU around. Those accolades don't come cheap, mind you, as retail cards start at £430 and run all the way up to £500.
We believe the better bet is the GeForce GTX 970. Sharing a lot of the qualities that make its bigger brother a sought-after GPU, the sibling card offers 80-90 per cent of the performance for just 60 per cent of the outlay. £255 buys you a GPU that is excellent in almost every regard. Nvidia's add-in card partners would do well to focus their efforts on the GTX 970, for it's destined to be become a hot seller.
Asus takes due note of the GTX 970's potential by releasing an overclocked card. Known as Strix DC2OC-4GD5 and using a massive cooler along with a couple of tricks not normally seen on graphics cards, let's take a closer look.
If you like your graphics big and beasty, you're in luck. Asus goes against the GTX 970 playbook with an elaborate cooler that's overkill for a GPU outfitted with a modest 145W TDP. And when we say big we mean big. The standard-sized backplate is dwarfed by the card, which measures 5.5in high and 11in long, so the Strix is not best suited for itty-bitty chassis.
Asus makes the most of this size by strapping a 10mm heatpipe snaking its way through the card-wide heatsink. Though it seems as one continuous heatpipe, three pipes converge at the core and make direct contact with the GPU. The Strix's bulk means the heatsink is 220 per cent larger than normal, and along with the extra-thick heatpipe(s), should offer class-leading thermal performance.
The Strix uses a four-segment approach to card design. Twin 10cm fans dominate the shroud. That large heatsink is obscured underneath, and Asus takes care in making sure the memory and VRMs have sufficient cooling. Nvidia supplies partners with schematics on how to integrate the GPU on to a card. It is then up to them to implement it the best way they see fit. Almost all of this card is non-standard, with custom capacitors, chokes, Digi+ VRM voltage modulation, and a six-phase supply feeding the core and memory. Rounding it off, a custom backplate adds a nice finishing touch.
Notice the single power source? Asus goes against convention and adds a (upside down) single 8-pin connector rather than the usual dual 6-pin. Most modern power supplies can manage this output just fine, with up to 225W of juice provided by the combination of PCIe cable and PCIe slot, but there's no adapter cable in the box for older PSUs.
You'd expect a card of this ilk to be equipped with a commensurately large overclock. Asus increases the base clock from 1,050MHz up to 1,114MHz, though the efficiencies of the Maxwell architecture enables a sufficiently higher boost clock in all scenarios.
Whereas the reference card peaks at 1,178MHz, the Strix jumps to an average 1,253MHz. Yet this is relatively conservative, because rivals such as Palit and EVGA routinely boost their premium GTX 970s to 1,300MHz+. There's no memory overclock to accompany the uplift on the GPU, either - Asus keeps the 4GB GDDR5 frame buffer ticking along at the default 7,012MHz.
Yet the massive cooler serves another purpose. Asus knows the energy-efficient Maxwell GM204 GPU is easy to cool, so the large dissipation area and hunk of copper and aluminium are put to a different use. The Strix's twin fans are inactive until the GPU temperature hits between 65°C and 69°C, where they begin spinning at just 1,200rpm. This means the card is silent during video playback and light gaming. Dota 2, for example, barely tickles the 1,664-core GPU; the fans remain switched off.
Nvidia's reference outputs include a trio of DisplayPort 1.2, HDMI 2.0 and dual-link DVI. Asus replaces one of the DisplayPort with DVI and drops the other one altogether. This doesn't make a whole heap of sense because the backplate section is the same size as the reference card's.
The cost of Asus going down the custom-designed route is a mid-overclocked card with a £300 street price, or £45 dearer than the cheapest GTX 970s available. More pertinently for the performance junkie, the asking price is higher than the better-overclocked EVGA GTX 970 FTW.
