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::>Graphics cards > 2014 > 07 > AMD Radeon R9 295X2

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29-07-2014


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AMD Radeon R9 295X2 graphics card: review and testing

Even people who are not dealing with computer have heard about the new dual-chip graphics card produced by company AMD. Even before the announcement of AMD Radeon R9 295X2, it became clear that the manufacturer is not going to save on resources, or to make any compromises. AMD company had done everything to the output is the world's fastest graphics card for the desktop systems. No, there is a competitor of "green" in the form of NVIDIA GeForce GTX TITAN Z, who also claims to these laurels. But now the performance in this model is not so good as stated at the beginning. And the recommended cost $ 3,000 is too high.

AMD Radeon R9 295X2

The task to create a dual-chip graphics card is quite difficult, and when it comes about solution based on GPU AMD Hawaii XT, it even seem impossible. The fact that the graphics adapters are limited in size and maximum power consumption, which according to the specification does not exceed 375 W (150 W through each of the two 8-pin connectors + 75 W through the slot PCI Express). And even if the first problem can be solved by using a printed circuit board with a large number of structural layers, in the second case, you must either artificially reduce the performance of each core, or just ignore the standards. That's what came by AMD, saying that TDP of the model AMD Radeon R9 295X2 will be at the level 500 W.

AMD Radeon R9 295X2

"Uncompromising power" says one slide of the presentation. These words characterize the result of company AMD. Graphics Card AMD Radeon R9 295X2 is based on two full graphics cores AMD Hawaii XT, each of which is made by a 28-nm technology process and includes 6.2 billion of transistors.

AMD Radeon R9 295X2

At the structural level hasno changes. It is based on advanced microarchitecture AMD Graphics Core Next, which has already been discussed in detail in reviews of graphics cards видеокарт GIGABYTE Radeon R9 280X Overclock Edition and AMD Radeon R9 290X. Therefore we present only the comparative characteristics:

 

AMD Radeon R9 295X2

AMD Radeon R9 290X

AMD Radeon HD 7990

Graphics core

2 х AMD Hawaii XT

AMD Hawaii XT

2 x Tahiti XT

Technology process, nm

28

28

28

Q-ty of transistors, billion

2 х 6,2

6,2

2 х 4,3

Q-ty of data-flow processors

2 х 2816

2816

2 х 2048

Q-ty of texture blocks

2 х 176

176

2 х 128

Q-ty of raster operation blocks

2 х 64

64

2 х 32

GPU clock frequency (in mode Boost), MHz

1018

1000

1000

Memory effective frequency, MHz

5000

5000

6000

Memory type

GDDR5

GDDR5

GDDR5

Memory capacity, GB

2 х 4

4

2 х 3

Memory bus size, bit

2 х 512

512

2 х 384

Memory carrying capacity , GB/s

2 х 320

320

2 х 288

TDP level, W

500

250

375

This table includes the previous dual-chip model AMD Radeon HD 7990. On the basis of its characteristics is easy to follow the progress has been made by AMD for this year: AMD Radeon R9 295X2 largely surpasses its predecessor according all key parameters. It is also noteworthy that each graphics core of the new product is faster by 18 MHz (Boost mode) than the AMD Radeon R9 290X. Thus, the manufacturer did not cut parameters of GPU, and even made its small optimization at the level of the clock frequency.

It is obvious that such impressive features are primarily designed to ensure a comfortable gameplay in the resolution 4K Ultra HD (3840 x 2160).

AMD Radeon R9 295X2

AMD Radeon R9 295X2

AMD Radeon R9 295X2

According to the results of testing conducted by the employees of the company, AMD Radeon R9 295X2 completely copes with itss task, and in most cases even superior combination of two graphics cards NVIDIA GeForce GTX TITAN Black. For reference AMD Radeon R9 295X2 will cost you the sum of 1,700 dollars, while the 2 x NVIDIA GeForce GTX TITAN Black will cost about $ 2,400.

AMD Radeon R9 295X2

However, in order to "feed" this "uncompromising power" it is required 500 W. You will say "And what's so special about it?" Almost every power supply on the market today is able to handle this load. In principle all right, but there is one "but". In fact, this load is consumed via channel +12 V, and therefore makes certain restrictions on used power sources. In particular, each of the 8-pin PCIe slots must be directly connected to a single line +12 V. At the same time it is strictly forbidden the use of any adapters. According to the specification, PCIe slot is designed for a load of 12.5 A, whereas in this case it will not be less than 18 A. In addition the used lines +12 V should not have any accessories, such as CPU, motherboard, etc. etc. In reality it is not easy to determine which virtual line +12 V should have connected components of the system.

Therefore, when selecting a power supply for the graphics card AMD Radeon R9 295X2 we recommend you follow such points:

  • The power supply capacity is calculated as follows: (500 W for graphics card + CPU TDP + 30W for the motherboard + 6W*amount of memory modules + 15 W*number of drives + 3 W*number of fans (including CPU cooler) + 15 W*number of drives) * 1.1 + 50 (100) W for a stock or in the case of acceleration components.
  • The output should have one powerful channel +12 V, instead of divided into multiple virtual lines +12 V.
  • Load capacity of the line should not be lower than: (A 42 + TDP of CPU / 12) * 1.1.
  • System stabilization should be implemented on separate principle instead of group. This will allow to avoid the effect of "skew" of voltage +5 V and +12 V raised due to uneven loading on these lines.
  • Each 8-pin PCIe connector must be located on a separate cable.
  • Do not use adapters Molex-PCIe (8-pin) and PCIe (6-pin) -PCIe (8-pin).

At first glance, this list looks a bit awesome, but do not worry too much. The market is full of devices that meet the above requirements, and the price tags are at quite an acceptable level.

AMD Radeon R9 295X2

Also a kind of revolution, AMD engineers made in the cooling system, having used a hybrid cooler which combines air and liquid cooling type. In principle, this technology is not new, but for the "reference" graphics card is used for the first time. In more details the capabilities of installed the cooling system will be discussed in the appropriate section.

AMD Radeon R9 295X2

As the produce belongs of the new family of graphics cards AMD Volcanic Islands, it supports all the latest technologies and developments in the field of: power saving feature AMD ZeroCore Power, API Mantle, improved sound processing AMD TrueAudio and the ability to create multi-monitor configurations with the help of technology AMD Eyefinity.

And now let's see how all this is implemented in practice. But first take another look at the detailed specifications of the Model AMD Radeon R9 295X2:

Model

AMD Radeon R9 295X2 

Graphics core

2 х AMD Hawaii XT

Q-ty of shader pipelines

5632 (2 х 2816)

Supported API and technologies

DirectX 11.2, OpenGL 4.3, AMD Mantle, AMD Eyefinity, AMD App Acceleration, AMD HD3D, AMD CrossFireX, AMD PowerPlay, AMD PowerTune, AMD ZeroCore Power, AMD TrueAudio

Graphics core frequency (in mode Boost), MHz

1018

Nominal memory frequency (effective), MHz

1250 (5000)

Memory capacity, GB

8 (2 x 4)

Bus type, bit

1024 (2 x 512)

Memory type

GDDR5

Bus type

PCI Express 3.0

Max resolution

DVI-D - 2560 x 1600

Mini DisplayPort - 4096 х 2160

Outputs

1 х DL DVI-D

4 х Mini DisplayPort

Support of HDCP and decoding of HD-video

Yes

Dimensions taken from official website (according measurements in own test lab) , mm

308 х 111 (320 х 112)

TDP level, W

500

Drivers

Drivers can be downloaded from GPU

Producer website

AMD

Design

We obtained test sample of the product so the description box and supplied set id absent.

AMD Radeon R9 295X2

A distinctive feature of all the dual-chip solutions including AMD Radeon R9 295X2 is a great length. According to data obtained in our lab, it reaches 320 mm. As for the other sizes, they are less outstanding. For example, new item height is 112 mm, and in case it will overlap only two slots. For a product of this level it is an absolute "plus", since it will allow to easily build the configuration of the two graphics cards AMD Radeon R9 295X2. Recall that in the current "top" solution of a series AMD Volcanic Islands for organizing the mode AMD CrossFireX mode special bridges are not required, because everything is carried out at the program level.

AMD Radeon R9 295X2

The appearance of the graphics card has Hi-Tech, using the original colors of AMD red and black. Much attention is also paid to the quality of used materials. Even traditional plastic casing is made of aluminum. Although in addition to the decorative function it also has a practical value: increases the rigidity of the graphics card and prevents sagging of its back part. Furthermore, it contacts with the inner support plate-radiator and thus is a part of the cooling system.

AMD Radeon R9 295X2

The cover has many holes and cuts for air removal.

AMD Radeon R9 295X2

To display an image on the AMD Radeon R9 295X2 the following set of interfaces is provided:

  • 1 x DL DVI-D (resolution up to 2560 x 1600);
  • 4 x Mini DisplayPort (resolution 4096 x 2160).

As a result, the graphics card can connect up to 4 monitors using the Mini DisplayPort ports or a combined circuit DL DVI-D + Mini DisplayPort.

AMD Radeon R9 295X2

During operation of AMD Radeon R9 295X2, its central fan is highlighted in red that will definitely please fans and owners of modding cases with side window. The fan on the radiator of liquid cooling system has not this feature.

Printed circuit board and circuitry

AMD Radeon R9 295X2

AMD Radeon R9 295X2

The circuit board has a very complicated configuration. Not only that the developers had to think about the placement of 2 GPUs, 32 chips of memory and their power subsystems, so they need to separate the two 512-bit buses. It is not surprising that when creating a PCB were used 14 structural layers and elements occupy both sides of the PCB.

AMD Radeon R9 295X2

AMD Radeon R9 295X2

The model AMD Radeon R9 295X2 uses a powerful 13-phase power subsystem: 5 phases allocated to each GPU, by one for each 4-gigabyte memory stack and one common for PLL. The quality of the element base has no complaints, because it is fully consistent with the level of the entire card: use the power components with high efficiency built according technology DirectFET; voltage filtration nodes include installed solid capacitors (mainly tantalum) and a coil with ferrite cores in sealed enclosures.

AMD Radeon R9 295X2

To control the VRM modules there are two PWM controllers NCP81022. One of them is located on the back side of the PCB. Also here are phase drivers of power converters.

AMD Radeon R9 295X2

In addition to slot PCI Express x16, power supplying of the product is provided via two additional 8-pin connectors. Do note that disconnection of connectors PCIe is quite conveniently, nothing prevents this process.

AMD Radeon R9 295X2

Also at the end of the graphics card you can find the usual switch for "top" solutions from AMD. In this case it is responsible for changing the operating mode (normal «Uber» and quiet «Quiet»). These modes set the speed of rotation of the central fan and maximum performance of graphics accelerator.

AMD Radeon R9 295X2

The basis of the product is two graphics chips AMD Radeon R9 290X (AMD Hawaii XT), which are made in accordance with the 28-nm process. They are based on the microarchitecture AMD Graphics Core Next (GCN) and include 2816 unified shader pipelines (stream processors), 64 Rops and 176 texture units. For calculation of the total computing power of graphics cards, the indices given above it is necessary to multiply by 2.

The operation frequency of each of the graphics core is equal to 1018 MHz versus 1,000 MHz of "reference" model of the single-chip AMD Radeon R9 290X. It is praiseworthy that the engineers of AMD could to not only maintain the characteristics of the GPU on the level of the standard version, but even increase some of them.

AMD Radeon R9 295X2

Memory of graphics card AMD Radeon R9 295X2 the total amount of which is 8 GB is collected from 32 chips SK hynix H5GC2H24BFR-T2C. Their effective frequency is equal to 5000 MHz. Although, according to the specifications it can be increased up to 6000 MHz. However, it will have to raise the voltage from 1.35 to 1.5 V. Thus, the memory manufacturer provided a pretty good potential of plant overclocking.

Data exchange between the graphics processor and memory is carried out by means of two 512-bit buses the capacity of each of them reaches 320 GB/s.

AMD Radeon R9 295X2

To connect two GPU to each other and to the interface PCI Express bridge PLX PEX8747 is used. It is a switch of bus PCI Express 3.0 with 48 lines. There are 16 lines for each GPU, another 16 lines have applied for video communication with the system.

Cooling system

AMD Radeon R9 295X2

As it was already mentioned, the manufacturer refused to use traditional air cooler in favor of a hybrid cooling system that includes a water cooling system, central fan and two radiators. We propose to consider each component in more detail.

AMD Radeon R9 295X2

Let's start with the most interesting - the liquid part of the cooling system. Water cooling system belong to the non-serving type of closed loop. That is, after buying a graphics card user does not need to make any action to build, fill and configure the system.

Instead of one large water-block, the manufacturer has applied two small, each of which is equipped with a built-in pump. Thus it was possible to solve the problem associated with low productivity of non-separable liquid cooling systems. Furthermore, each water block cools only one graphic core, which also increases the overall efficiency of water cooling system.

AMD Radeon R9 295X2

Their manufacturer is the company Asetek, which specializes in products for liquid cooling systems. To increase the heat transfer rate a copper base is applied. Inside it has a microchannel structure.

AMD Radeon R9 295X2

The second part of the water cooling system is a 120mm radiator with a fan attached to it. It is recommended to install it in such way that the air flow from the fan should be removed out of a PC case.

AMD Radeon R9 295X2

Optimal location of radiator is presented in this scheme.

AMD Radeon R9 295X2

For its blowing is used 120mm fan Power Logic PLA12025S12M with capacity of 2.4 W, based on the plain bearing. Here the position of the engineers at AMD remains a mystery for us. Why with the product cost about 1700 dollars it is saved on quality of fans?

The disadvantages of this water cooling system include the absence of speed control system of 120mm fan. Rather, it is present but the range of its operation is very narrow, as the fan is connected directly to the pump. As a result we have the following situation: at maximum load rotation speed 120mm fan is 1900 rpm, and in idle mode (even in case of the graphics core deactivation) it is 1700 rpm. This in turn will lead to excess noise in places where it could have been avoided. Although it should be noted that over the subjective level "below average" it did not rise.

AMD Radeon R9 295X2

AMD Radeon R9 295X2

Passive part of the cooler consists of two aluminum plates. They are designed for cooling the chip memory and increase the stiffness of the whole structure. The removal of heat from the power elements of the power is provided by means of a more efficient copper radiator. Thermal paste was used as thermal interface.

AMD Radeon R9 295X2

The last component of the cooler is the central 85 mm fan FirstD FD9015U12S with capacity of 6.6 W. Unfortunately, it is also based on the plain bearing.

As we’ve mentioned earlier, the aluminum case also has a role in the process of cooling of model AMD Radeon R9 295X2. In particular, it helps to distribute the airflow over the entire length graphics card generated by central fan.

Now let's evaluate the effectiveness of the cooling system in practice. The utility MSI Afterburner was used to monitor the performance of accelerator.

AMD Radeon R9 295X2

In case of continuous maximum load the temperature of graphics cores did not exceed 56°C, which is an excellent result for the product of this level. Particularly impressive it looks at the background of indicators (80°C and above), recorded during the testing of single-chip solutions AMD Radeon R9 290X with a traditional air cooler.

Moreover, according the heat level of graphics core the model AMD Radeon R9 295X2 could surpass the graphics card PowerColor LCS R9 290X 4GB GDDR5 OC, which also was cooled using water cooling system. Thus, we can conclude that the experts of the company AMD together with engineers of Asetek could create a really very effective and at the same relatively compact cooling system. As for the noise, during the experiment it was at a fairly comfortable level.

AMD Radeon R9 295X2


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