ASUS R9 280X DirectCU II TOP & R9 270 DirectCU II OC Reviewccokeman - March 9, 2014
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ASUS R9 280X DirectCU II TOP Closer Look:
There is no doubt about it that the R9 280X DirectCU II TOP is loaded for bear with a ten phase power delivery system, a big factory overclock, and one of ASUS' DirectCU II cooling solutions to keep the thermals in check. Built on the same 28nm Tahiti-based silicon as the HD 7970, we are not seeing a whole lot new when comparing cards of the same DNA. Where we do see a little something new, is with the fan package used on this card, which uses the Cooltech technology to deliver the airflow through the heat sink for temperatures that are up to 20% cooler than the reference design. Measuring 11.2 x 5.7 x 1.5 inches, the R9 280X DirectCU II TOP is a full size package that will occupy a pair of PCIe worth of space, while only using one 16x PCIe 3.0 slot in the motherboard.
The front view shows the card caries that red and black theme that is still so popular with the gamers. A pair of massive fans occupy most of the shroud with a quartet of heat pipes emerging from under the fin array. On the back side, the black PCB is covered in surface mount electronics. From the factory, ASUS covers most of the connection point with covers to protect them during and after the shipping to the consumer.
Display connectivity includes a pair of DVI ports, one DVI-I, one DVI-D, an HDMI Port, and a single full size DisplayPort connection. The back end of the card initially does not look like there is much going on, until you flip the card over to see that the fin array overhangs the PCB by about half an inch. But that's not all you see. In the middle of the PCB are voltage measurement points and solder points to connect to a motherboard, such as the Rampage IV Extreme or Maximus VI Extreme that supports ASUS VGA hot wire functionality. This feature allows the user to solder on leads to the PCB to enhance the voltage control to the on-board components. A feature that sets this card apart from those of ASUS' competitors.
Power connectivity for the R9 280X DirectCU II TOP includes a 6-pin PCIe and 8-pin PCIe power connector to deliver up to 225 watts on top of the 75 watts pulled from the PCIe slot. A power supply of 600 watts should be at the low end of the requirement for this type of card. Under each power connection on the PCB are a pair of LEDs, which indicate whether or not you have an active power connection to the card. This is one of ASUS' Protective Design features. Red means you may not have gotten the power plug into the socket fully or not at all, while showing green means all is good as far as the power supply is concerned.
A pair of CrossFire bridge connections allows up to four cards to be used in a CrossFire configuration as long as your motherboard, power supply, significant other, and wallet are all on the same page. Keeping the PCB from developing a case of the bends, is a brace across the spine of the card that keeps the PCB all in one plane to prevent cracked traces in the PCB from ruining your day. At this point the robust cooling solution used on current generation video cards make this feature almost mandatory.
The direct contact based cooling solution comes off the PCB by removing the four spring loaded screws that hold it against the core. Underneath the cooling solution, we get to see what makes the R9 280X DirectCU II TOP tick. ASUS' Digi+ VRM controller is used with a ten phase (8+2) Super Alloy Power circuit to deliver gains in operating efficiency, overall life span of the components, and a reduction in card electronic noise thanks to the Super Alloy Power concrete filled chokes. By using this feature set you get a 30% increase in voltage stability for improved overclocking, a 15% overall gain in power efficiency, and a 2.5x boost in the lifespan of the SAP capacitors. A large aluminum cooler covers the mosfets and receives the bulk of its cooling from the pair of 100mm Cooltech fans. At the back end of the PCB is the Digi+ all-digital VRM controller, which enables the user to tweak the voltages and clock speeds, as well as monitor critical operating parameters through software utilities such as ASUS' own full-featured GPU Tweak application.
The ASUS DirectCU II cooling solution is very robust on this card. There are a total of five nickel plated copper heat pipes, including a massive 10mm heat pipe that carries up to 85 watts of thermal load compared to the 60 watts carried by an 8mm heat pipe. On this design, ASUS uses one 10mm pipe, two 8mm heat pipes, and a pair of 6mm heat pipes to carry the thermal load from the Tahiti XTL core to the large aluminum fin array. The contact surface is comprised purely of the copper heat pipes, unlike some solutions that separate the heat pipes with part of the aluminum base, which is a less efficient design. Compared to a reference cooler, ASUS' cooling solution offers almost 55% more surface area available for cooling the GPU core and board components.
On the R9 280X DirectCU II TOP, ASUS uses what it calls Cooltech technology fans to deliver improved airflow through the heat sink. To do so, they used a new fan design that combines the best attributes of a blower and axial fan to improve cooling performance without increasing noise levels. What we see in use is a hybrid fan paired with an axial fan, both of them 100mm in size that, when combined, deliver a 20% improvement in cooling over the reference design. Noise levels take a 3x reduction when compared to a reference design as well.
This card is built upon 28nm Tahiti XT silicon much like the HD 7970 was built using an earlier DNA sequence. Outside of special edition cards like the Matrix, Mars, or Poseidon, ASUS TOP video cards often have a better binned core that allow it to achieve higher clock speeds right out of the box. In that respect, ASUS equips the R9 280X DirectCU II TOP with a core clock speed of 1070MHz from the factory. Not as high as I have seen with other cards, but fully stable at 1070MHz, of course with some overclocking headroom left for the enthusiast; even more with the use of ASUS' VGA Hotwire feature set.
Specs wise, we see the same 2048 streaming processors, 128 texture units, and 32 ROPS we are used to seeing with the R9 280X. On-board GDDR5 memory is from SK Hynix in a 3GB capacity running through a 384-Bit bus. These Hynix modules, part number H5GQ2H24AFR R0C, are rated for operation at 6.0Gbps using 1.5v. ASUS puts a little squeeze on them from the factory, running the memory at 6.4Gbps. Even so, there still is a little meat on the bone it seems on this card.
The R9 280X DirectCU II is factory-equipped to run the numbers and deliver a great gaming experience. Let's see if the R9 270 DirectCU II OC has the same special feature sets.