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Review: Asus GeForce GTX 780 DirectCU II OC

by Tarinder Sandhu on 15 July 2013, 16:00


Quick Link: HEXUS.net/qabyoz

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The card

A trio of Nvidia's 7-series GPUs arrived in quick succession just a couple of months ago. For the most part, two of these GPUs - GTX 770 and GTX 760 - were newer takes on existing 6-series designs. A boost in frequencies here, an addition of GPU Boost v2.0 there, and there you go, the GTX 680 became the GTX 770 and the GTX 660 Ti the GTX 760. But now shipping with lower pricing and increased performance over the older cards, it's all good news for the consumer.

The £500-plus GTX 780 is a different beast, however, as it's based on the wider, more powerful Kepler GK110 architecture that also powers the GTX Titan. A little more work has to be done when constructing a retail card, though we've seen the likes of Palit, Gigabyte, and EVGA make a decent fist of it.

But there remain GTX 780 alternatives that we've yet to take a look at, with manufacturers promising even better performance, thermals and noise characteristics. One such card is the Asus GeForce GTX 780 DirectCU II OC, so let's get busy with it.

It's big, really big, measuring 287mm long and almost 150mm high, thus making it the largest GTX 780 card to pass through the labs. Wider cards are nothing new - this one is about 20mm longer than the reference - but the reason for the extra height is down to Asus cramming in five thick heatpipes that run off in both directions from the twin-fan heatsink.

You see, four 'pipes - two thick, two thin - extend towards the bottom, so much so that they could potentially foul other components if the heatsink hadn't been shifted upwards. Build quality is excellent and the best we've seen on a partner GTX 780 thus far. By the very nature of the design, cooling is open air, meaning air is recirculated around the chassis. All other things being equal, we'd prefer a closed design, a la reference, that funnels air straight out of the back.

That fifth heatpipe juts out of top. Taking no cooling prisoners, Asus uses a 10mm-thick version that runs from the core through to the middle of the aluminium heatsink. In case you're wondering, part of the card's name, DirectCU, is derived from the fact that the five heatpipes are flattened at the point at which they touch the core. The obvious premise is to get the best-possible contact with the GK110 die underneath.

Weighing in at 1,145g, Asus sensibly has a brace running along the top edge of the card. A wide backplate is there for more than just show, too, as it acts like a large heatsink when the card is running at full beans. Power is sourced by the usual combination of one 8-pin and one 6-pin connector, though on this card the connectors are rotated by 180° - they clip in 'upside-down', making installation easier. There are also two visual indicators directly below the connectors, signifying, via green LEDs, that the power delivery is as expected.

Focussing on non-reference attributes, the card carries upgraded power regulation (ostensibly for overclocking), voltage-monitoring points (left-hand edge of rear heatsink) and 10cm fans that are designed for low-noise operation. Note that the fans are different in appearance; the left-hand one has eight blades while 10 closer-spaced blades make up the right-hand fan.

With all this focus on power regulation and performance, it would be reasonable to expect the DirectCU II to be amongst the fastest out-of-the-box GTX 780s on the market. This, sadly, is not the case, as the card ships at a core speed of 889MHz, rising to an average of 941MHz under the auspice of GPU Boost v2.0. Compare this with the 980/1,033MHz and 967/1,020MHz core settings of the Palit and EVGA overclocked versions, respectively, and it's hard to see why Asus has been so conservative.

The company is of the opinion the shipping speed doesn't mean all that much when GPU Boost v2.0 is factored in, and the DirectCU II's cooling and thermals will allow it to boost with the best of them. Whatever the rationale, we'd prefer to see higher out-of-the-box clocks.

The 3GB memory, meanwhile, is left at a standard 6,008MHz. Take the core and memory frequencies together - 889/6,008MHz - and you'll realise the card is specified at barely above reference speeds of 863/6,008MHz.

Notice just how much wider the card is than the standard backplate? Non-standard in many forms, the DirectCU II does retain reference-like outputs of DVI-I, DVI-D, HDMI and DisplayPort.

Backed by a three-year warranty and likely to ship at the £600 mark, or up to £80 more than the cheapest GTX 780s, there's plenty to like, other than the anaemic frequencies and, potentially, price. Will its performance be knockin' on Titan's door? Let's find out.