In the world of Small Form Factor builds you are always compromising. You either have to give up some performance for a smaller size or give up some size to get the performance you are looking for. Recently though, this trend has been starting to change. My last LAN build was easy to carry around while having (at the time) the second fastest GPU from Nvidia and a high end CPU. Of course because of my GPU I couldn’t go any smaller. Asus has a new GPU that is going to change that. Their new GTX 670 Direct CU Mini is the same length of a MiniITX motherboard. With that size, my LAN rig is going to need a complete rebuild.. To go smaller!

Product Name: Asus GTX 670 Direct CU Mini - GTX670-DCMOC-2GD5

Review Sample Provided by: Asus

Written by: Wes

Pictures by: Wes

Packaging

The first thing I noticed about the GTX 760 Direct CU Mini was its size. The box is smaller than most other video card boxes we get in. With such a small card there isn’t any reason for the box to be large. The cover of the box has most of the important information including the model, memory capacity, overclocked, a note about its size, and even a photo of the card as well, well at least of the heatsink. Around on the back side Asus has focused on showing off the DirectCU Mini’s size as well as its cooling. Part of that includes a pictures that really just sells the card for me where they have the card on a Mini ITX motherboard and the card is the same length of the motherboard. Right away that tells me that this card is going to fit and work in builds that all of the other cards won’t support due to their length. I also love the line drawn diagram of the cards connections to make sure your monitor will support the card before you get it home.  

Inside the box I found the DirectCU Mini snug in its foam protection along with a cutout with all of the accessories included with the card. You get a setup guide, the driver and software disc and a two six pin to one 8 pin adapter cable just in case your power supply doesn’t have the connections needed for the Direct CU Mini.

Card Layout and Photos

Even on our forums we saw big interest in the GTX 670 DirectCU Mini when it was first introduced both because of its size as well as its styling. Asus is well known for having a unique style that is both clean and eye catching. The GTX 670 DirectCU Mini, despite its size continues that tradition. You have a mostly black fan shroud with a small area of red in the bottom left corner. The red draws you to the Asus logo. The CoolTech fan design that Asus went with on this card is very unique looking as well. Rather than having normal fan blades, each blade has a twist in it. When you look at the card from its side you can see a lot more of the DirectCU heatsink than you normally would. Speaking of the DirectCU, Asus uses their normal design that mounts a vapor chamber directly on the GPU and helps spread the heat around to the heatsink. The cooling of the GTX 670 DirectCU Mini plays a big role in its size, even the GTX 650 DirectCU II that I took a look at a while back had a MUCH larger cooling design, on a card that generates less heat even. Because of that a lot of the design of the GTX 670 DirectCU Mini is about keeping temperatures under control, without that this form factor wouldn’t be possible at all. 

I do love that the top of the GTX 670 DirectCU Mini has a nice DirectCU Mini logo up top. Most cases that you would use this card in won’t have side panel windows, but even then Asus did keep that in mind when designing the card. My only nitpick would be the lack of the GTX 670 on there as well to show off how powerful of a card you have in your new small form factor build.

As with most cards with non-reference cooling the GTX 670 DirectCU Mini does have a semi open air design in order to get the air flow needed to keep things cool in such a small package. This does mean that not all of the heat that the card generates will be going out the back of the case and it could add a little more to the interior temperatures. This is especially important in the small form factor cases that this is designed for. Because of that if you build a rig with a GTX 670 DirectCU Mini be sure that you are keeping an eye on temperatures to make sure you don’t have any unforeseen issues. 

The size of the GTX 670 DirectCU Mini is most obvious when I put it up next to the reference GTX 670. The GTX 670 DirectCU Mini is considerably shorter than the reference design with its extended cooling design. The GTX 670 DirectCU Mini is a little taller than the reference card though in order to be able to pack all of Asus’s features into such a small package. When you put them together you can also see how much larger the GTX 670 DirectCU Mini’s CoolTech fan is over the reference fan. Originally I thought that maybe Asus just used the reference PCB design, but with its additional height made it obvious that this isn’t what Asus did. After looking closer the PCB is actually slightly shorter than the reference PCB. When you compare the two PCB’s you can see that the Asus design is cleaner/more efficient. Interestingly the GTX 670 DirectCU Mini doesn’t have a support bracket while the reference design does.

Although the GTX 670 DirectCU Mini is taller than a reference card, it does have the same two SLI bridge connections that you would find on a reference GTX 670. That means if you have two or three GTX 670 DirectCU Mini’s you could run them in SLI, but due to the unique design you couldn’t just mix them with a reference card.

For power, Asus changed things up as well. The reference design of the GTX 670 used two six pin connections to feed its power. To help with the smaller size Asus went with a single 8 pin power connection on the GTX 670 DirectCU Mini. This is possible because two 6 pin cables supply 75 watts each while one 8 pin is regulated at 150 watts. This is why you sometimes see two six pin to 8 pin adapters, like what was included with this card.

This view of the rear PCI Slot shows the additional height well as well as the GTX 670 DirectCU Mini’s multiple connection types. You can run DisplayPort and HDMI in their full sizes as well as dual DVI connections. One of the DVI ports will support VGA pass-through via an adapter (bottom in the photo) while the other connection is all digital.

I already showed off the back of the GTX 670 DirectCU Mini in the comparison photos with the reference card. But here we can focus on one of Asus’s most interesting feature. To make it even easier they have even pointed an arrow to it with a label. This would be the Direct Power logo in the middle of the card on the back of the GPU. This can be used as a small heatsink but more importantly it shows that Asus changed from the reference design and placed the GPU VRM directly next to the GPU itself. This gives the GPU high quality and reliable power delivery and Asus claims this lowers overall PCB temperatures by 17%. It’s also important to note that the Direct Power logo is actually upside down when you look at the card sitting up, this is because when the card is in your PC it will read correctly, a small but nice touch.

Our Test Rig and Procedures

Cooling, Noise, and Power

Asus spent a lot of time tuning and tweaking the GTX 670 DirectCU Mini’s design in order to be able to make it all work in such a small form factor. Because of that I was very interested to see what its cooling performance was going to be when I put it on the test bench. I didn’t expect it to outperform all of the cards that are nearly twice its size but I was really hoping to see it out perform the reference design. At 77 degree under load it just that, barely. It’s not a number to be all that proud of when taken on its own, but being such a small card with a high end GPU under the hood I think we can be a little forgiving, not to mention the GTX 670 DirectCU Mini is actually overclocked over the reference design as well.

With the unique fan design I was curious to see how it would perform in my noise testing. I ran the card through both idle and full fan speed tests to see the range of noise that you can expect. At idle the GTX 670 DirectCU Mini came in at the middle of the pack, but the differences between cards are extremely small. Under 100% fan speed the GTX 670 DirectCU Mini did come in a little higher at 75.2 decibels, slightly higher than the reference GTX 670 performed. I can only assume that Asus had to give up some of its noise performance to make the small card possible. 

In my power testing at idle the GTX 670 DirectCU Mini was three watts higher than the reference GTX 670. The different cooling design could have played a role in that, along with the higher base clock speed (928MHz vs. 915MHz). Under load the difference was more with the fully loaded test bench with water cooling and a 3860X the GTX 670 DirectCU Mini pulled 403 against the reference cards 378. That difference is without a doubt due to the overclock that Asus included bumping the boost clock up from 980MHz to 1006MHz. 

Synthetic Benchmarks

While synthetic benchmarks aren’t a great representation of actual game performance you might see. They are a great way to compare the performance between cards without having to worry about small inconsistency’s that can happen in hand run benchmarks especially. Not only that but there is less of a worry of tuning that favors specific manufactures, something we see a lot with games. This is why the first benchmarks I look at are our synthetic benchmarks, especially in this case. I want to see how well the GTX 670 DirectCU Mini performs up against the reference GTX 670 as well as all of the cards that have come out in the past year. In our regular 3DMark Fire Strike benchmark the GTX 670 DirectCU Mini came in right in between all of our GTX 760’s with the only card that out performed it being the heavily overclocked Hawk card from MSI. As for the GTX 670 reference card the GTX 670 DirectCU Mini pulled ahead of it by a fairly good number. Results from the extreme Fire Strike benchmark weren’t as favoring though, in fact the GTX 670 DirectCU Mini performed slower than the reference card by a large margin, I’m not sure if this is related to driver changes or if the extreme benchmark overheated the GTX 670 DirectCU Mini. Hopefully we will get more answers in the rest of our testing.

3DMark 11 results came in right in line with what we saw in the first Fire Strike benchmark even when I turned the setting up too high. It’s looking more like the Fire Strike Extreme results may have been flawed more than anything. The Unreal Heaven Benchmark results were more of the same as well. The heavily overclocked Hawk card did outperform the GTX 670 DirectCU Mini, but only slightly while the performance over the reference GTX 670 was more than noticeable.

In Game Benchmarks

We could talk synthetic benchmarks all day, but at the end of th day the only thing that is going to matter is how the GTX 670 DirectCU Mini performs when you get into your favorite games. So what I have done is put it through our benchmark suite of 12 different games that cover a range of game types as well as AMD/Nvidia backing. Hopefully you will find a few games that you are interested in the results. So how did the GTX 670 DirectCU Mini perform? Well for starters, in some games like Sleeping Dogs, the overclocked card came remarkably close in performance to the GTX 680. I was also impressed with Bioshock where it actually matched the performance I saw with two GTX 650 Ti’s in SLI, not bad for half the cards in half the length. In most benchmarks though the results mirrored the synthetic results where the GTX 670 DirectCU Mini comes in slightly higher than all of the GTX 760’s other than the highly overclocked Hawk card. Considering every one of those cards was nearly twice the size of the GTX 670 DirectCU Mini I would consider that a win. Even more importantly you can expect playable performance in every game that you throw at the card, even at the highest settings like most of our benchmarks.

Overclocking

I’ll be honest, with a factory overclock already combined with the cooling limitations that the smaller form factor gives you I wasn’t all that confident that I would be able to push the DirectCU Mini all that hard. I pressed on and put it through our standard benchmarking suite that consists of breaking down the overclock by core clock and memory, pushing their limits, and then testing them in test 2 of 3DMark 11 on performance settings. I started with GPU core clock overclocking and as you can see in my documentation below the results weren’t as bad as I expected but still not as high as I think I could have gotten with additional cooling. Even so, a clock speed of 1359MHz is still very impressive! When I moved on to memory overclocking I was able to push the limit much farther, to the point where I got worried that I was going to damage the card. In the end I was able to run a 700MHz memory clock offset without experiencing any issues. Lastly I put the two together and ran them to see if they would run. Oddly enough they passed the first time through but the second time I didn’t have as good of luck, even with a slightly lower memory clock. This was most likely due to temperatures, had I let the card cool all the way down it would have been okay. If I were to overclock the card day to day though, I would be looking to take a noticeable drop from these numbers for reliability.

Overall and Final Verdict

Asus went out of their way to do something completely different with the GTX 670 DirectCU Mini. Because of that they have come up with a product that is the only real option for people looking for top shelf performance in a small form factor build. Sure you could work around it with a slightly larger case that fits a longer card, but if you are looking to push the limits of size and performance this is the way to go. They took a good performing card and designed a PCB that incorporated all of Asus’s features like their Direct Power and then come up with a cooling design that was able to keep it all cool. Even more impressive is on top of all of that they also slipped in a little bit of an overclock as a bonus. Really the only downside at this point is where its price point lands against the GTX 760 that performed close to the DirectCU Mini. Or course you should expect to pay a bit of a premium for a unique card like this. Currently you can even get a little more of a discount on it with a rebate being offered. I can’t wait to show off the build I’m putting together that takes advantage of the GTX 670 DirectCU Mini; let’s just say it puts my last LAN rig to shame both in performance and size.

Author Bio

Author: garfi3ldWebsite: http://lanoc.org

Editor-in-chief

You might call him obsessed or just a hardcore geek. Wes's obsession with gaming hardware and gadgets isn't anything new, he could be found taking things apart even as a child. When not poking around in PC's he can be found playing League of Legends, Awesomenauts, or Civilization 5 or watching a wide variety of TV shows and Movies. A car guy at heart, the same things that draw him into tweaking cars apply when building good looking fast computers. If you are interested in writing for Wes here at LanOC you can reach out to him directly using our contact form.