NVIDIA’s GK104 based graphics cards made quite a splash while being used in some of the GTX 600 series cards, and now they make their presence known in the GTX 700 series as well. Today, we have a GTX 770 series card from ASUS to check out – the GTX 770 DirectCU II OC. We just knew ASUS was going to take the GTX 770 reference design, beef up the power delivery, and overclock it. It’s what they do after all! So, let’s take this latest offering from ASUS for a test drive and see how well their efforts have paid off.
Specifications and Features
Here are the specifications pulled from the ASUS press deck. Of special note here is the GPU base and boost clock increase from the reference design’s 1046/1085. The 7010 MHz memory clock, 1536 CUDA cores, and a 256 bit memory bus interface are the same as the reference design, but are impressive statistics in their own right.
A quick glance at GPU-Z confirms what we see above and adds a few other details.
Typically, the ASUS DirectCU II graphics cards are packed with special features, and that doesn’t change this time around either. The slides below outline some of the high level features you can expect when purchasing this card. We’ll be going into more detail of the other features as we progress through the review, but here is a snippet to whet your appetite. The main message here is higher GPU clocks, cooler and quieter operation, a robust power delivery design, and a software package designed to get the maximum performance possible. All these high level features equate to an enhanced experience when compared to the reference design cards.
Packaging and First Look
What has become a familiar theme applied to ASUS DirectCU II graphics cards packaging continues on here as well. High level features are mentioned on the box front, while the back of the box goes into greater detail on a few others. All of the box sides are reserved for additional branding and make a point of getting that DirectCU II cooler in your face.
Even though the outer carton design is well used, I’ve seen ASUS use several variations for housing the product inside. In this particular case, ASUS shows a bit of a box fetish. Once inside the outer box, we have another box with a nice gold ASUS emblem, and inside that box is yet another box that houses the accessories. Once through the maze of boxes, we finally come to the graphics card sitting at the bottom. The card is well-protected in a foam bed that should be adequate to protect the card during transportation.
The scant accessories include a driver/software CD, installation manual, and a 4-pin Molex to dual PCIe power cable.
With a pile of cardboard set aside, we can get a better look at this attractive graphics card. We’ll get into more detail of the different areas as the review progresses, but for now enjoy the picture show!
A Closer Look/Under the Hood
In order to power the GTX 770 DirectCU II OC, you need both 6-pin and 8-pin PCIe power leads, or you can use the provided power adapter cable found in the accessories. There are two LEDs located just below the power connections that will glow red if bad power or no power is connected. If you see green lights – all systems go! The display connection options are plentiful and include Dual Link DVI-I, Dual Link DVI-D, DisplayPort, and HDMI. The GTX 770 series graphics cards also support Tri-SLI, and you’ll find the appropriate bridge connections at the top of the card.
In order to remove the DirectCU II cooling apparatus, there are only four spring loaded screws that need to be removed. Once that is done, the whole assembly is easily taken off. The easy method of removing the DirectCU II cooler is intentional by design, which allows for easy cleaning and maintenance. The application of TIM was a little on the heavy side, but nothing alarming. By removing four more smaller screws, the outer fan shroud can be separated from the heatsink.
Inside the fan shroud, we find two FirstD fans, which we find in video cards from many manufacturers. I’ve never encountered any problems with FirstD fans, and they seem to be a popular choice in proprietary video card coolers. These particular fans are marked with a model number of FD7010M125, and I measured them to be right at 100 mm in size. Where the fans separate themselves from others is with their dust-proof design. ASUS says by double sealing the housing and bearing assembly areas, and thus the dust entry points, you can expect a 25% greater fan lifespan.
The heatsink is comprised of a high density aluminum fin stack with three heatpipes. Two of the heatpipes engage the long and short sides of the heatsink, while the third passes through the longer side only. All three copper heatpipes pass through the aluminum base and make direct contact with the GPU core. History tells me when copper heatpipes make direct contact with the surface to be cooled, the thermal performance is noticeably better when compared to other designs where the heatpipes do not make contact with the target area. The entire DirectCU II cooler is a huge improvement from the reference design cooler and should perform substantially better, both in thermal capacity and noise levels.
For additional cooling, ASUS has implemented a small heatsink over the MOSFETs and a backplate. The backplate also helps to prevent the card from flexing and sagging. The MOSFET heatsink and thermal pad were found to be making excellent contact with the intended surfaces. The dedicated MOSFET heatsink is yet another cooling feature the reference design does not incorporate. Given the MOSFETs are typically the hottest part of any VRM design, it’s nice to see ASUS adding this heatsink.
Now that we have a naked card, let’s have a look around! The critically acclaimed Super Alloy Power features are visible from this vantage point and are incorporated into the 10-phase power delivery (8 GPU – 2 Memory) design. The 10-phase power design is vastly larger than the 6-phase power design found on the reference cards. The Super Alloy Power features include Super Alloy Caps, Super Alloy Chokes, and Super Alloy MOS. When compared to the reference PCB, take a good look at the power delivery area… this ain’t no reference design PCB folks!
Not all chokes are created equal, and the ASUS SAP chokes have some tangible advantages over traditional chokes. The Super Alloy Chokes are reinforced with an alloy formula to help reduce temperatures, protect against EMI, and improve power output. One of the other benefits of the Super Alloy Choke design ASUS uses is the reduction of coil whine, or in some cases, elimination of it all together.
The SAP 5K capacitors also offer distinct advantages over traditional capacitors found on many competing cards. ASUS claims the Super Alloy capacitors will increase the lifespan of their cards to 150,000 hours, resulting in a 2.5 times greater lifespan when compared to traditional cards. Exactly what these “traditional” cards are is anyone’s guess, but I’ll assume they’re the type that use the old electrolyte capacitors. The SAP capacitors are also said to increase the maximum voltage threshold by 30% and are rated for 5K operation versus the industry standard of 2K.
The Super Alloy MOS feature promises a 30% increase in the maximum voltage threshold via a 35 V MOS working in conjunction with 3 V capacitors. The end result being better overclocking capability, we’ll be finding out!
And the brains behind the Super Alloy Power? Well, the all digital DIGI+ VRM, of course. The three slides below appear to be based off of testing done using a HD 6970; but ASUS must feel the results will be the same with the GTX 770, or they probably wouldn’t have included them in the press deck. Anytime you can keep voltage noise to a minimum, it’s an added bonus. ASUS compares the voltage noise reduction the DIGI+ VRM provides based on a comparison to traditional analog designs. With its ability to intelligently transfer current to the 10 power phases, DIGI+ VRM can reduce power loss and maximize power efficiency. DIGI+ VRM also has the ability to dynamically adjust frequencies to help reduce EMI and the noise associated with it.
One other important item the DIGI+ VRM design brings us is the SAP CAP feature, which places high performance capacitors directly underneath the GPU. Putting these capacitors directly under the GPU will allow for efficient and instant access to stored capacitance.
As long as we are looking at the back of the PCB, I thought I’d mention something the ROG Extreme motherboard owners might like to see. The GTX 770 DirectCU II OC supports the VGA Hotwire feature! With a compatible ROG Extreme motherboard, you can use the solder points to attach wires that get plugged into the appropriate spot on the motherboard. Once the wiring task is complete you can adjust GPU, Memory, and PLL voltage and monitor them as well.
Just as ASUS has spoiled their motherboard users with the feature packed AI Suite software package, they aim to do the same for their graphics card users via the GPU Tweak real-time graphics tuning software. GPU Tweak has everything you need to fine tune and monitor almost anything on your graphics card. With GPU-Z being integrated into the utility, you get a very familiar interface when you need to view the graphics card information. You also have the ability to save up to six profiles for easy retrieval of your favorite customizations.
Upon opening GPU Tweak, you land in the tuning section where you will find all the overclocking options. What options are actually visible here will be dependent on the video card you have. Down the left hand side, you have the live update button for automatically updating the vBIOS. If you click on the settings button, you will find five tabs where you can customize the different areas of GPU Tweak. The info button is used to open the ASUS skinned version of GPU-Z. Further down the left side are three more smaller buttons. The top one is used for starting a benchmark of your choice, which you can set up under the Tune tab in the settings area. The next button is where you can toggle between standard and advanced mode. The bottom button will open the monitor window, which gives you real time values for voltage usage, temperatures, clock speeds, and more. One cool thing about the monitoring window is that you can hover your mouse over it and see the values at any given point of the timeline.
Here is a series of screen shots showing all the different areas within GPU Tweak, along with a couple of ASUS provided slides.
Performance and Overclocking
- ASUS Maximus V Formula Motherboard (Oveclockers Approved!)
- G.SKILL Trident X (2 x 8 GB) DDR3 2400 F3-2400C10D-16GTX @ 18666 MHz 9-9-9-24
- Kingston 3K SSD 240 GB (Overclockers Approved!)
- Intel i7 3770K Processor @ 4.0 GHz (Overclockers Approved!)
- Water Cooled/Swiftech Apogee HD CPU Block
- Corsair HX1050 PSU
- ASUS GTX 770 DirectCU II OC – 320.18 Driver
Since April of last year, we have been using our new “Updated Video Card Testing Procedure“. If you are not yet familiar with it, click the provided link to learn more. Below is the down and dirty version of the new procedure.
- All Synthetic benchmarks were at their default settings
- Unigine Heaven (HWbot) was run using the “extreme” setting
- Aliens vs. Predator – 1920×1080 with highest settings offered (4x AA, textures set to highest)
- Battlefield 3 – 1920×1080 at Ultra settings (4xAA/HBAO by default)
- Dirt 3 - 1920×1080 with 8x MSAA and all settings enabled and at Ultra where possible
- Metro 2033 – 1920×1080, DX11, Very High, 4x MSAA/ 16x AF, PhysX OFF, DOF enabled, Scene: Frontline
- Civilization V – 1920×1080, 8x MSAA, VSync OFF, High Detail Strategic View: Enabled, Other Settings: High, using full render frames value ( / 60)
- Batman: Arkham City – 1920×1080, VSync off, 8xMSAA, MVSS and HBAO, Tessellation set to high, Extreme Detail Level, PhysX Off
Overclocking for Stability
Just like the NVIDIA Titan and GTX 780 cards, the GTX 770 makes use of the new GPU Boost 2.0 technology. If you haven’t made yourself familiar with what GPU Boost 2.0 is all about, please visit the NVIDIA Titan introduction posted back in February. hokiealumnus did a great job of explaining how it works. In a nutshell, we now have thermal controlled maximum boost clocks and a small amount of voltage control that GPUB 1.0 took away. Once the default temperature threshold of 80 °C is reached, whatever overclock you have set will be reduced (and voltage along with it) until you are under the temperature threshold. The good news is if you are more concerned with speed than noise levels, you have options. First of all, you can manually ramp up the fan speeds to keep things cooled down, or you can simply raise the temperature threshold if you have software that allows it. Luckily, GPU Tweak has all these options at your disposal.
I was able to get the GPU core stable at 1250 MHz boost, but under load that equates to 1293 MHz. Remember, when looking at GPU-Z, the reported boost clock value is just an estimate of the average GPU speed during typical load scenarios. If you monitor the GPU Boost speed while the card is under load, you typically see a constant value much higher than what GPU-Z shows. As a side note, the voltage increase allotment is very small. In my case, I could only raise it from 1.200 to 1.212, which is just this side of nothing really. This isn’t the fault of ASUS by any means, but rather the limits put forth by NVIDIA no doubt.
On the memory side, I was able to get 2004 MHz (8016 MHz Quad Pumped) stable enough to finish all of the tests in our benchmark suite. Overall, we have a pretty nice final overclock, especially considering it’s overclocked from the factory to begin with. I spent a good amount of time dialing this overclock in, so I doubt we’ll have anything left for the “Pushing the Limits” section.
Armed with our stable overclock for charting purposes, let’s get on with the benchmark results! Beginning our synthetic testing with 3DMark03, you can see we actually beat out the GTX 780 and HD 7950 when this card was overclocked. This is a pretty old benchmark, and results are not really relevant to modern gaming; but the benchmarking crowd still enjoys how well it scales. So, while the test results can be a good dose of eye candy, I wouldn’t hold to much stock in them.
A much more relevant test for today’s gaming is 3DMark Vantage. Here again, we see a victory over the GTX 780 when this card is overclocked. At stock speed, it again had a good showing and fell right inline where expected.
In the 3DMark11 benchmark, we see this card knocking on the door of the GTX 780 when overclocked. At stock, it came darn close to the HD 7970 too!
3DMark Fire Strike is the newest edition to our benchmarking suite. Now that we have amassed a decent amount of comparable data, I’m sure you’ll be seeing more of it in future graphics card reviews. Once again, the ASUS GTX 770 DirectCU II OC threw out a great number when overclocked and took out the HD 7970. At its stock speed, it fell right in line as expected. You probably noticed by now that this card scales very nicely when overclocked!
Our last synthetic benchmark comes in the form of HWBot Heaven. Once again, both the overclocked and stock results are pretty darn impressive. So far, this card is showing consistent stock GTX 780 type scores when overclocked.
A great overall showing in our synthetic benchmarks, let’s move on to some real world gaming results and see how the GTX 770 DirectCU II OC performs there.
In alphabetical order, we begin with Aliens vs. Predator DX 11. Here we see the pecking order just as it should be, but we did get a 10 FPS increase when overclocked.
In Batman: Arkham City, the test results showed great scaling when overclocked and managed to take out the HD 7970 at that setting. When left at stock speeds, the results fell back to the expected pecking order.
Overclocked or not, the pecking order remained in tact during our Battlefield 3 test. But, once again the scaling was impressive with a 12.5 FPS gain.
Same story in our Civilization V test, but yet again impressive scaling was had. There was a 15 FPS increase when the card was overclocked.
Dirt 3 is probably the least demanding of all our gaming benchmarks, but it’s a very popular game nonetheless. Here we saw an impressive stock score when compared to the GTX 780, losing out by less than 1 FPS. When overclocked, only the Titan managed a higher score.
The bone crusher in our gaming benchmark suite is none other than Metro 2033 with maxed out settings. It definitely takes an upper-end graphics card to reach a playable 30 FPS in this benchmark, and I’m happy to report the GTX 770 DirectCU II OC got there.
Power Consumption and Temperatures
Our power consumption testing is done with a Kill-a-Watt and wattage usage recorded at idle and load. We run both HWBot Heaven and 3DMark 11 (Combined Physics Test) to hopefully get the maximum power draw the video card can produce. I tend to take this testing one step further and also provide results while the video card is overclocked.
Amazing. That’s about the only word I can think of to describe how little power these modern graphics cards use. I mean seriously, with the card overclocked to the hilt and put under a constant 100% load, I couldn’t even get 350 watts worth of power draw. Amazing!
Overclockers’ temperature testing procedure requires running HWBot Heaven at both stock and overclocked settings. The results are normalized to 25 °C ambient. I ran tests with the fan control set to auto, and then again with the fan speed set to 100%. As you can see by the graph below, the temperatures never came close to reaching the default thermal limit of 80 °C. As far as I’m concerned, you can set the fan on auto mode and leave it there – at stock or overclocked.
Pushing the Limits
As I expected, I pretty much maxed out the overclock at the settings mentioned above. However, let’s throw a 5.0 GHz CPU overclock in the mix and see what a few of our synthetic tests come up with.
We managed to top 40,000 in 3DMark Vantage by adding the CPU overclock to the benchmark run…. nothing to complain about there!
HWBot Heaven is almost exclusively GPU dependent, so increasing the CPU speed didn’t really result in much of an increase, but we did manage to top 2500 for a score. I was also able to increase the memory speed a couple of notches and complete the run at 8016 MHz.
3DMark Fire Strike also completed with the 8016 MHz memory setting, and came up with a final score of over 7900.
Currently the ASUS GTX 770 DirectCUII OC is selling for $409.99 at Newegg. The entire GTX 770 product line seems to be selling anywhere from $399.99, up to $449.99 for the models with 4 GB of memory. So, the price is right where I would expect it to be when compared to others on the market.
For those of you who are ASUS graphics card fans, you’ll be happy to know all the features you have come accustom to are still there. From the DIGI+ VRM to the Super Alloy Power features… it’s all there. You’ll find the stout 10-phase power design and the Direct CU II cooler to be huge upgrades from the reference design cards. The DirectCU II cooler works so well in fact, there is no reason to ever take it off the auto setting… even when overclocked to the max. If you haven’t owned an ASUS video card in the past, the GTX 770 DirectCU II OC should definitely be considered if your looking at purchasing something in this price range.
As far as performance goes, it owned the GTX 680 and HD 7950 in our tests. It even managed to equal the GTX 780 a time or two when overclocked, and held its own against the HD 7970 along the way. Speaking of overclocking, the card did quite well on both the GPU and Memory side of things, even with the minimal voltage increase that’s available. GPU Tweak is a full featured GPU software package that makes working with the card very easy. With GPU Tweak you have control of all aspects of the card, whether that be overclocking or thermal related.
In the end, we have a great performing, good looking, well priced, and feature rich video card on our hands here.