XFX R7770 Black EditionS Super Overclocked (FX-777A-ZD)

INTRODUCTION

The Radeon HD 7900 series, codenamed Tahiti, was the first product off the Southern Island family of GPUs that AMD launched on December 22, 2011. This marks a new era of GPU architecture from AMD as it ushers in the Graphics Core Next (GCN), which brings a greater computing power to the GPU. Based on a completely new design, the Southern Island’s stream processors are organized in AMD’s SIMD-based GNC architecture, which is AMD's answer to NVIDIA’s Fermi architecture.

Tahiti was the first 28nm GPU manufactured by TSMC. It is also the first card that supports PCI-E 3.0 and Direct3D 11.1. The end result was that not only is Tahiti the most powerful GPU on the market today, its computing power has been improved significantly.

As always, once the high performance cards appeare on the market, both NVIDIA and AMD will release mainstream derivatives based on the same architecture and technology except a few features or functional unit disabled to make ways for the mainstream and budget products.

With Tahiti out of the gate, AMD is ready to show off the Cape Verde, the mainstream cards targeted at $100-200. Often times, companies release the top-of-the-line cards first, followed by midrange cards, followed by the entry-level. This time, however, AMD went straight to the bottom first after launching the Tahiti. AMD still has plans to release mid-level cards but that will have to come at a later time, and today is all about Cape Verde. Two cards will be launched today: the HD 7770 and the HD 7750. The cards are designed as the successor to the HD 6870 and the HD 6850.

HD 7700 Series: Cape Verde

The last generation mainstream GPU from AMD—the HD 6870 and HD 6850 features fundamentally same 5-way VLIW architecture as the HD 5000 series. While AMD is able to tweak the card’s performance to keep it competitive, its aging architecture is long overdue for an overhaul. With the Cape Verde utilizing the same GCN design as the top of the line product, we should expect the card to have much more powerful computing power while its GPU power should stay relatively comparable.

Obviously since Cape Verde is based on the same architecture as Tahiti, we should expect the same features found on Tahiti to be on Cape Verde. This includes second generation Eyefinity, HD3D Technology, Supersample Anti-Aliasing, PowerTune Technology, ZeroCore Power Technology, Discrete Digital Multipoint Audio (DDMA), and AMD Steady Video 2.0. In addition, the GPU also supports FP64 but only limited to 1/16th FP32 performnace.

Like its bigger brother, the Cape Verde also supports a wide range of ports which includes HDMI 1.4a, 3GHz and DP 1.2 HBR2. Up to 4096x2160 (UHD) displays are supported.

The HD 7700 series cards all feature 512KB of L2 Read-Write cache, and 16 ROPs. Packed in are 1.5 billion transistors. The bigger of the two cards, the HD 7770 has 10 Compute Units (CU) for a total of 640 Stream Processors. The GPU is clocked at 1GHz with 1GB of 128-bit GDDR5 clocked in at 1,125MHz (4500 effective). This works out to be 72GB/s memory bandwidth and 1.28 TFLOPS of computing power. At 1GHz clockspeed, the HD 7770 is, in fact, the first factory clocked GPU on the market. AMD rates the card’s typical power consumption to be 80 watts while consuming less than 3 watts of long idle power.

The HD 7750 is going to be the lowest end for the current generation of architecture GCN form AMD. The card will have 512 stream processors. The GPU is clocked at 800MHz with 1GB of 128-bit of GDDR5 running at 1,125 MHz (4500 effective). AMD quotes the card to have a typical 55W of power consumption with less than 3 watts of long idle power. The card will have 819 GFLOPS of compute performance and 72GB/s memory bandwidth.

AMD's launching price for the HD 7750 and the HD 7770 are $109 and $159 respectively. The pricing of the card puts the HD 7770 in direct competition against AMD's own HD 6850 and HD 6870. The pricing of the card also means that the card should be faster than NVIDIA's GTX 550 Ti and slower than the GTX 560.