A fresh look at Polaris / Video cards

NVIDIA and AMD have differently entered the epoch of GPU, manufactured at the rate of 14/16 nm. The first one left the upper price segment of gaming accelerators, releasing GeForce GTX 1070 and GTX 1080 and only later – more affordable GTX 1060 . AMD began with the "productive" category ( Radeon RX 480 ), from which the architecture of Polaris also began to develop downward (RX 460 and RX 470 ), and over time the technical process of 14 nm, which uses AMD, will spread to top gaming products (Vega architecture).

In the confrontation between the RX 480 and the GTX 1060, the lines chosen by the rivals crossed, making us witness the hottest and most unpredictable (for fans who had not previously discussed the specifications of competing devices) fights in the time that has elapsed since AMD and NVIDIA released the first products using 28 nm technology in 2011-2012. The result is already known to us: the GTX 1060 is a faster card, but the RX 480 is cheaper just to justify the difference in performance.

Nevertheless, in the reference version of the RX 480, it's easy to see that the frequency parameters that AMD has installed are hard to come by both the Polaris 10 chip and other components of the card – the cooler and the voltage converter. Overclocking GPU on the reference board frankly disappoints, especially in light of expectations about the process technology of 14 nm FinFET. But the original design devices breathed new hope into the hearts of AMD supporters. SAPPHIRE NITRO + Radeon RX 480 was the first card from this galaxy, which we will have to test.

# On the power supply system of the reference Radeon RX 480

In the footsteps of the first reviews of the RX 480 on the Internet, information about problems with the power supply system of reference samples spilled out, but to frequencies and overclocking they are not directly related. We will make a small digression to clarify the situation.

Some sources reported that the Radeon RX 480 in the reference version exceeds the claimed TDP (150W), and the power lines in the PCI Express slot are loaded more than required by the standard, up to 90W against relying 75W. The top motherboards prepared for overclocking video cards are on the shoulder, but cheaper models are threatened by burnout of the conductors in the connector (such cases have already been reported, although the influence of the user's hand curves or even deliberate misinformation is not excluded).

The presence of only one six-pin auxiliary power connector (75 watts according to the standard) is also uncharacteristic for video cards with 150W power consumption. But this point, in fact, does not matter, since the RX 480 can take from a six-pin connector up to 150 watts of power, without overloading (overheating) it. For many readers this is an unexpected statement, so we will explain what is meant.

The PCI-SIG association instructs the six-pin connector to have two 12-volt circuits (plus and ground for each) and another ground contact (Sense A on the circuit), through which the device recognizes that the power cable is connected. One remaining contact is not used in theory, but most PSUs supply another "plus" with 12 V. It's like many other video cards that use this "plus" and "ground" of Sense A as a third 12 V circuit.

And if it were not so, the limitations of power connectors make sense only in the context of heating wires and are not a problem for the consumer of energy. Even the thinnest wire used in computer power supplies for connecting floppy drives (20 AWG) is rated at 11 amps at 12V (which, when using two circuits, gives a power of 264W). At the same time, the temperature of the wire, theoretically, will not exceed acceptable for isolation (albeit alarming from the position of common sense) 60 ° C.

AMD as a result recognized both shortcomings, in which they accused the reference model Radeon RX 480. In the package Radeon Software Crimson Edition 16.7.1, the power balance between the PCI Express slot and the additional power connector is corrected, and a separate tick in the settings leads TDP to the declared value 150 W, albeit at the price of an imperceptible decrease in productivity.

However, we repeat: neither the overload of power lines in the PCI Express slot nor the presence of a single six-pin auxiliary power connector themselves explain the limited frequency potential of the Radeon RX 480. The confusion with the reference version of the Radeon RX 480 is only an indirect sign that AMD , most likely, shortly before the release of new items increased the frequency and voltage supply Polaris 10 in order to meet the GeForce GTX 1060 fully armed, and the previously designed board and cooling system as a result exhausted their capabilities without leaving a reserve for further acceleration. From partnership cards of original design, we expect more.

# Technical characteristics, the complete set of the delivery, the price

SAPPHIRE NITRO + Radeon RX 480 exists in two versions, differing in the amount of RAM – 4 and 8 GB. In addition, the 4-gigabyte version uses slower chips with a bandwidth of 7, rather than 8 Gbit / s per contact.

GPU on SAPPHIRE boards works on such frequencies that the lower version (1306 MHz) on the Boost Clock level has gone from the overclocked reference RX 480 (1315 MHz), which we have in 3DNews. The older version of NITRO + RX 480 exceeds this level (1342 MHz). Both SAPPHIRE cards are characterized by TDP at the reference value level of 150 W.

As for the prices, the Radeon RX 480, officially sold since June 29, is still not so easy to buy. Most of the offers on the American site negwegg.com currently represent reference maps, and all of them are mostly bought up at the moment (01.08.2016). Yandex.Market did not find any products of the original design, but at least reference cards in Russia can be bought.

SAPPHIRE NITRO + Radeon RX 480 itself is estimated by the manufacturer at $ 219 and $ 269-279 (for versions with 4 and 8 GB of RAM, respectively). The older version was found on newegg.com at the maximum price specified by SAPPHIRE, which is $ 50 higher than the recommended value set by AMD, and corresponds to the cheaper GeForce GTX 1060 with frequencies slightly higher than the reference ones.

The manufacturer
The model NITRO + Radeon RX 480 4GB NITRO + Radeon RX 480 8GB Radeon RX 480
The graphic processor
The code name Polaris 10 Polaris 10 Polaris 10
The microarchitecture GCN 1.3 GCN 1.3 GCN 1.3
The technical process, nm 14 FinFET 14 FinFET 14 FinFET
The number of transistors, million
Clock frequency, MHz: Base Clock / Boost Clock 1208/1306 1208/1342 1120/1266
The number of stream processors 2,304 2,304 2,304
The number of textural blocks 144 144 144
The number of ROP 32 32 32
Operative memory
The width of the tire, bit 256 256 256
The type of the microcircuits GDDR5 SDRAM GDDR5 SDRAM GDDR5 SDRAM
Clock frequency, MHz (throughput, Mbit / s per contact) 1,750 (7,000) 2,000 (8,000) 1,750 (7,000) / 2,000 (8,000)
The volume, Mbyte 4,096 8,192 4,096 / 8 192
The input / output bus PCI Express 3.0 x16 PCI Express 3.0 x16 PCI Express 3.0 x16
Computational power, FP32, GFLOPS (from the Boost Clock calculation) 6,018 5,800 5,834
Performance of FP32 / FP64 1/16 1/16 1/16
Throughput of operative memory, Gbyte / s 196 224 196/224
The conclusion of the image
The interfaces of the image output DL DVI, HDMI 2.0b, DisplayPort 1.3 / 1.4 DL DVI, HDMI 2.0b, DisplayPort 1.3 / 1.4 DL DVI, HDMI 2.0b, DisplayPort 1.3 / 1.4
TDP, W 150 150 150
Retail price (USA, without taxes), $ 219 269-279 199/229 (recommended, at time of publication)
The retail price (Russia), rubles 19,500 (expected) 25,000 (expected) 16 310/18 970

The video card is delivered in a compact package, typical for SAPPHIRE, without any accessories. All that is inside, in addition to the device itself, is paper documentation and a CD with software.


Unlike the reference version of the RX 480 with a turbine cooler, the SAPPHIRE product is cooled by an open design system. The case of the video card is shorter than the reference version, but much wider than the printed circuit board (this should be borne in mind when installing NITRO + RX 480 in thin cases). Thus, part of the radiator located inside, "hangs" from the board and is blown through by fans – SAPPHIRE has already applied similar solutions before.

The back surface of the board is covered with an aluminum plate which protects the parts that have been removed on it and stiffens the whole structure.



Many manufacturers have timed to the release of video cards of a new generation from NVIDIA and AMD a change in the design and design of their products. SAPPHIRE, following the general fashion, has equipped the card with RGB-LEDs. The logo on the side of the casing can be set to an arbitrary color using the SAPPHIRE TRIXX 3.0 utility (not yet published at the moment) or by pressing the red button on the back of the board select one of the automatic modes: constant blue backlight, "Rainbow", color temperature display of the GPU or fan speed.

Whereas the reference version of the RX 480 for GPU cooling uses a monolithic aluminum radiator with a copper insert in the center, SAPPHIRE used a more complex design. The central copper block is connected to the finning by three heat pipes, and two separate "soles" are pressed against the RAM chips and VRM transistors.

The airflow creates a pair of 95 mm diameter fans on double ball bearings. Due to the fact that each fan is held in place by a single screw and connected through a connector, they are dismantled without having to remove the cooling system cover and solder the wires.



# Fee

Developers changed the configuration of video outputs, standard for AMD-based video cards based on Polaris, adding a DVI-D port and changing one of the DisplayPort connectors to HDMI. Thus, you can connect a screen with an HDMI interface and a virtual reality helmet to the video card at the same time (they all currently use HDMI).

A common feature of cards on AMD chips is a dual BIOS – here it is used to switch between two speed modes: one with reference frequencies, the other with "factory overclocking" to frequencies specified in the specifications table.

The board voltage converter is built according to the 5 + 1 phase scheme (for GPU and RAM power supply respectively), not including PLL. The voltage on the GPU is controlled by the IR 3567B PWM controller, which is based on AMD Radeon R9 290X video cards. The power part of the circuit includes durable polymer capacitors and proprietary throttles with ribbed "micro radiators" Black Diamond 4. According to the manufacturer, they are heated by 15% less compared to the previous iteration.

Note: SAPPHIRE forbade journalists to disassemble test samples, but in return provided their own photos of the payment. They show a version with 4 GB of RAM. We will test the older model.

The later manufacturer said that in the cards that will go on sale, one of the GPU phases will be dismantled, that is, it will eventually have the same configuration as the reference PCB.



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