ASUS GTX 780 DirectCU II OC Graphics Card Review

ASUS has gone and done it now. They’ve brought out a beast of a custom-PCB GTX 780 – the new ASUS GTX 780 DirectCU II OC. It takes the reference GTX 780 design, throws it out the window and starts over from scratch, with some great looking results. Let’s have a look at what it can do!

Specifications & Features

The GTX 780 DirectCU II OC (also referenced GTX 780 DCU) isn’t overclocked very far from the stock GTX 780, at 889 MHz base / 941 MHz rated boost (vs. 863 / 900 on reference cards). That’s typical of ASUS offerings; they like to let you do the overclocking. EVGA usually overclocks much higher (see the Classified we reviewed previously) but in the end, all 780s will clock about the same. It’s just personal preference whether you want yours higher at “stock” or not.

We all know that’s not the full boost story though. With the strong cooler on this card, it keeps far away from its temperature target (with almost total silence) so it maintains the full boost while in use. In this case, the actual boost clocks at stock come in at a strong 1019 MHz.

The reference GTX 780 boosted to 1006 MHz at stock, so the difference between actual boosts isn’t quite as far as the rated boost clocks.

ASUS is very proud of this card. They spent a lot of time developing both the card and the cooler. They have a right to be proud, it’s a great looking card.

Now we’ll meet the beast itself.

Meet the ASUS GTX 780 DirectCU II OC

Speaking of beasts, it seems the three-fingered beast that lives in ASUS HQ is alive and well, slashing up all their GPU boxes for some reason or another.

You know the card contained within is a premium card when you see ASUS’ classy, charcoal gray box-in-a-box for accessories. Speaking of which, this card comes with a dual-6-pin-PCIe -to- 8-pin PCIe adapter, SLI bridge, and the speed setup guide & driver disc. It’s nice to see an included SLI bridge actually; most NVIDIA cards depend on the motherboard manufacturers to include them.

Now, ASUS’ coup de gras, the GTX 780 DirectCU II OC. Pictures really don’t do this thing justice; it is a very nice looking GPU.

It’s nice to see an included backplate. If you look around the GPU, there is actually a nice stiffening indentation on either side to prevent flex from the cooler’s weight. The cooling solution is very well thought-out. Here are some more photos for your viewing pleasure.

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Like all GTX 780’s, the GTX 780 DCU has official support for tri-SLI. They may be able to function in quad-SLI, but you’re way past the point of diminishing multi-GPU returns outside of competitive benchmarking.

There are two power connectors, one 8-pin PCIe and one 6-pin PCIe. ASUS outfitted this one with blue & green LEDs (you can see them right next to the connectors) that give you an instant at-a-glance notice if either of your power plugs aren’t making good connections.

Video outputs are standard NVIDIA fare, with two DVI, one HDMI and one full size DisplayPort output.

This is ASUS’ ace in the hole. It’s not labeled, probably because NVIDIA hasn’t hidden its disdain for voltage control, but this, ladies and gentlemen, is a set of solder points for VGA HotWire! If you have a recent ASUS Extreme motherboard (i.e. Maximus VI Extreme, Maximus V Extreme or Rampage IV Extreme), you can solder leads to them from this card and have full GPU, RAM & PLL voltage control.

Very obviously, this will void your warranty. Soldering a card always will. However, this is about the easiest possible method of soldering and is difficult to mess up if you have any idea what you’re doing with a soldering iron. This is the best of both worlds for NVIDIA – one of their top GTX 700 series cards gets actual, honest-to-goodness voltage control AND it’s as easy as it can be to tell the warranty is void, thus ending any liability on their part for a dead GPU. Unfortunately, without a proper vBIOS (which we’ll cover laster in “pushing the limits”), this feature isn’t going to do a whole lot for you. It’s both exciting and disappointing for now.

Now we’ll pull this card apart and see what lurks under that cooler.

Under the Hood

The thermal paste was generously applied and evenly distributed, no complaints there. Now you’re starting to see the custom PCB as well. ASUS wisely included a separate MOSFET heatsink, which not only serves its purpose on air, but is also pre-installed and ready to go for extreme cooling. There is also one other nice touch – a stiffening bar. This card won’t be flexing any time soon. That bar is screwed into the PCIe bracket right where the case screws will be holding the GPU. Extending most of the length of the card, that bar is a great add-on to strengthen this GPU.

Here are the parts all laid out side-by-side.

The MOSFET heatsink comes with a thermal pad and there is good contact throughout. This is also your first peek at the massive power section on this card.

Ahh, here is the raw PCB itself. Fully custom, front to back, this is what the GTX 780 is meant to be. No more weak reference NVIDIA power section, this one is built for power.

The newly designed DirectCU II cooler comes complete with five heatpipes total with copious amounts of aluminum fins for the fans to blow through. In a significant change from last generation’s DirectCU II coolers, this one is a space saving dual-slot design.

While this cooler is named a DirectCU II cooler, it seems to be one in name only. This is completely redesigned with new fans, more heatpipes, one giant 10 mm heatpipe and a nice looking, slightly more aggressive fan shroud.

One of the two fans is an interesting design as well, with an inner ring of fins that is supposed to help increase airflow and widen the airflow path. Both of these fans are ASUS’ dust proof design as well, which should help the fans’ bearings last longer.

As mentioned, there are five heatpipes total, with one massive 10 mm heatpipe in the other direction.

Here are a few more angles of new heatsink goodness.

So we’ve got a very solid cooler for the GPU; great news there. Regrettably, there is no contact with the GDDR5 video RAM to be found. That’s pretty much OK though, because you can’t raise the voltage on that via software.

If you do choose to use the VGA Hotwire controls (and void your warranty doing so), but don’t want to use extreme cooling, I would avoid raising the memory voltage. Gains for ambient cooling on memory will be small and not lead to real-world FPS gains. Only extreme benchmarkers need to worry about over-volting their memory, and it will be plenty cold when they do so.

Enough about cooling, let’s look at the card itself. First up, we have the 2 GB GDDR5 frame buffer that surrounds the GTX 780 GPU and only on this side of the card. Thus, all of the memory does benefit from the airflow through the heatsink even without direct contact.

The memory comes courtesy Samsung K4G20325FD-FC03 ICs, rated for up to 1.545 V and operating at 1502 MHz (6008 MHz quad-pumped GDDR5).

Now we have the monster NVIDIA GK110 itself. It’s not quite a Titan-level GK110, but the GTX 780 is a beast in its own right.

Now we get to what really separates the big boy GTX 780s from the reference cards – power. The GTX 780 DCU uses the same two power connectors, one 6-pin PCIe and one 8-pin PCIe. That’s where the similarities stop.

Controlled by ASUS’ DIGI+ VRM controller (a re-branded CHiL controller with proprietary firmware as far as we can tell), there are ten total power phases on this card, eight for the GPU and two for the memory.

You can read as well as I can regurgitate, so I’ll spare you. There is a lot of marketing-speak here, but the real takeaway is that the components used on ASUS’ GTX 780 DirectCU II OC are most definitely upgraded from the relatively weak components used in the reference power design. The components are stronger and, equally important, there are more of them.

While I would never recommend volt-modding a stock GTX 780 (you’ll blow up the power section in a few seconds), I would have no qualms at all about taking advantage of VGA Hotwire and running the heck out of this power section.

Just look at it. Copious amounts of capacitance. Myriad MOSFETs. Innumerable inductors. In short: moar powah!

Here is the VGA Hotwire section. It’s not labeled, but it’s here none-the-less. We have a video showing you how to solder these points, which has been posted on our forum for a while. Due to vBIOS quirks we won’t be using this today, but plan a follow up article down the road.

This PCB is so pretty, I just felt like one more photo, then we can get this thing installed and see what it can do.

Test Setup

Our test setup is that used across our reviewing team, consisting of a Haswell CPU clocked at 4.0 GHz and RAM at DDR3-1866 with 9-9-9-24 timings. We’ve got a big lineup of high-end cards to compare to today for you as well.

Red Maximus VI Extreme + red G.Skill RAM + this new DirectCU II heatsink = dead sexy!

Overclocking

Overclocking comes to this card via ASUS’ GPU Tweak software. Everything you need is here, from over-voltage & overclocking to monitoring and even their own skinned version of GPUz.

At the maximum allowable GPU voltage (1.212 V), this card managed a GPU offset of +175 MHz and a memory offset of +1000 MHz (250 MHz actual), which isn’t too shabby at all.

This overclock passed all of our testing of course, but here’s 3DMark Fire Strike at these settings.

The rated boost at that speed was 1066 MHz, but in actual usage the overclocked boost (which never wavered) ends up being a solid 1149.7 MHz.

This card overclocked quite well; nothing to complain about in this department.

Temperature and Power Consumption

Temperatures were very good on this card. The new DirectCU II cooler did a great job. Remember too, these temperatures are on the default fan profile, which means it prefers silence over cooling. Even with that it has stellar results, not even topping 60 °C!

Silent it was too, absolutely quiet. If you put your ear up to the card, you could hear some air blowing but that’s about it. Even cranked up for overclocking the card was remarkably quiet. The fans aren’t noisy at all; the only thing you’ll hear at high speed is the whooshing of air through the heatsink’s fins.

The power consumption department shows results typical of NVIDIA’s next-to-highest-end GPU, pulling just under 330 watts at the maximum. Really, for a GPU this powerful, that is impressively efficient.

Cool temperatures and (relatively) low power consumption. Still looking great.

Performance Results

Our performance results are gathered using our across-the-site universal GPU testing procedures, which you can see here. Long story short: benchmarks are run at their default settings, games are run at 1080p with everything turned up to the max.

Synthetic Benchmarks

In the synthetic tests, you can see the GTX 780 DirectCU II OC is strong at stock, but not quite as strong as the EVGA GTX 780 SC, due to EVGA’s much more aggressive stock clocks. However, once you overclock the 780 DCU it not only jumps over the GTX 780 SC, but also beats the much more expensive GTX TITAN. In the more GPU-intensive Heaven and 3DMark Fire Strike, overclocked results beat the TITAN by a very substantial margin.

Benchmarking clearly shows the GTX 780 DirectCU II OC is a powerful card. Now we’ll see how that translates in real-world gaming.

Game Testing

With the exception of Civilization V (which has the GTX 780 SC performing the best), every gaming result mirrors the benchmarks, with the stock GTX 780 DirectCU II OC coming in below the higher-clocked GTX 780 SC and the overclocked 780 DCU beating out its bigger, more expensive TITAN brother.

Crysis 3 has a different GPU lineup because so far I’m the only one testing with it. There are others that have gotten the game now though, so you can expect this lineup to grow over time.

These are killer results, when mere software overclocking beats out a GPU that costs over $300 more (the essence of overclocking, after all, is to get more for your money!); and with a card that is only $10 more than their reference model.  So far so good for the GTX 780 DirectCU II OC.

Pushing the Limits

When you overclock the CPU to 4.8 GHz and push the GPU to the absolute bleeding edge of “stability” (enough to complete the benchmark), you end up with some even better results from the GTX 780 DirectCU II OC. It pulled out scores you see below that would make a slightly overclocked TITAN jealous.

Ultimately, we aren’t going to stop there though. The GTX 780 DirectCU II OC has a trick up its sleeve – easy volt-modding. For those willing to break out their soldering iron, there are even higher clocks to be had. We have volt-modded our card but are having some issues with its BIOS throttling at higher voltages.

As we’re still ironing that out, we’re going ahead and publishing the review as-is, with the hopes that we can resolve that and come back with another article showing what this GPU can do when pushed even harder. So for now, these are the best scores we could get without voltage control.

If you want to try your hand – remember, there isn’t a vBIOS that both ditches the PowerTarget limit and keeps the card from throttling – you can check out my forum post outlining how to complete the voltage mod here. As always, you do that kind of thing at your own risk. If you don’t know what you’re doing, don’t do it. Neither we nor ASUS will be held responsible for a dead card from using that information.

Final Thoughts & Conclusion

First off, this is a great graphics card. Its performance at stock beats out the reference GTX 780 (duh; it’s overclocked) and its overclocked results beat out the much more expensive GTX TITAN. Even better, the ASUS GTX 780 DirectCU II OC retails for $669.99. That’s merely $10-20 over reference models (depending on brand and stock clocks).

For a card of this caliber, with its stellar build quality and heavily upgraded power section, that is a straight up steal. Add to that the fact that its cooler is very much upgraded from the reference cooler and the fact that you can volt mod it extremely easily, it’s just a hell of a deal.

Being able to beat out a more expensive model is the heart of overclocking. Obviously we’re not talking about a $200 CPU being able to hang with a $300 CPU; this is a different league. This is the very high end being able to hang with and surpass the ultra high end. Even so, since the very beginning overclocking has been about getting more bang for your buck. This GPU delivers, in a way that “saves” you over $300. The only thing a TITAN has that this doesn’t have (aside from double precision compute, which gamers don’t care about) is a 6 GB frame buffer. Now, if you’re using three monitors or a 4K display, perhaps that’s something that could make you want to consider going with the big dog.

However, if you’re a gamer or benchmarker and you just want absolutely stellar performance – equivalent to the TITAN and more – a GPU that’s built like a tank and a heatsink that will keep your GPU a whole lot cooler than the reference blower, the ASUS GTX 780 DirectCU II OC has your name written all over it. For only $10-20 more than a reference GTX 780, the GTX 780 DirectCU II OC is a total no-brainer.

– Jeremy Vaughan (hokiealumnus)

As mentioned, we’re working with ASUS to push overclocking even farther using the volt modding “feature”. Obviously this will totally void your warranty and isn’t something most people will seek to do, so we felt confident moving forward without that section included in the review. Once we get some throttling hiccups ironed out, we’ll bring you a follow up article on pushing the GTX 780 DirectCU II OC to its limits over and above what normal, sane people (that don’t want to take a soldering iron to their $670 GPU) will do.