Club 3D HD7970 royalAce Review

👤by Richard Weatherstone Comments 📅05-06-13
Specification

The HD7900 series features the Tahiti core which is the successor to the Caymen core of the HD6900 family. The Caymen core was based on a 40nm manufacturing process so it is fair to say that perhaps the biggest improvement to the Tahiti core is the reduction to 28nm process. This has enabled AMD to cram 4.31 billion (4,312,711,873) transistors into the new HD7970 core as opposed to the 2.64 billion on the HD6970 Caymen XT.

Comprising of what AMD calls 'Graphics Core Next (GCN)' archetecture which is optimised for heterogeneous computing, the new Tahiti core has upto 32 CU's (compute units) with dual geometry engines along with 8 back-ends comprising of 32 colour ROPs per clock and 128 Z/Stencil ROPs per clock. Each CU has a Vector unit and Scaler Co-Processor and can execute instructions from multiple kernels.

The VLIW4 SIMD has evolved to the GCN quad SIMD which equates to similar computational power yet grants better performance, threading and simplification. The GCN also has a new Cache hierarchy with 16KB instruction Cache and32KB Scaler Cache shared between 4 CU's. The L2 Cache is accessible by each CU with it's own separate process to ensure coherency. These changes increase the GFLOPs by 140%.

Tesselation on the Tahiti core is also enhanced by increased Vertex re-use off-core which theoretically at least, means the 7900 series has 4 times the throughput of the 69XX series. The are improved ansioscopic filtering algorithms too which come at no performance cost allegedly. These new algorithm improvement will allow the use of Forward Rendering with 1000's of potential light sources and will also mean MSAA can be rendered easily.



Looking at the schematics above, we can identify the bulk of the GPU is taken up with the 32 CU's. Above these are the geometry engines. To the left and right are the 8 Render back-ends, 4 each side. There's 768KB of L2 cache along with 6x64bit dual channel memory controllers making a 384-bit GDDR5 memory interface capable of delivering up to 264GB/sec. All of technology coupled together is transferred through a fully compatible PCI Express 3.0 x16 bus interface. Have no fear though because the cards are backwards compatible with PCIe 2.0.

Model
Product Name: Radeon HD 7970 royalAce
Product Series: Radeon HD 7000
Item Code: CGAX-7977SO
EAN Code: 8717249411185

Interface
Bus Interface: PCI Express 3.0

Chipset
GPU Chipset: Tahiti XT2
GPU Clock: 1050 MHz
Boost clock: 1100 MHz
Stream Processors: 2048

Multi-GPU
Multi-GPU: Quad CrossFire Ready

Memory
Memory Size: 3072MB
Memory Interface: 384BIT
Memory Type: GDDR5
Memory Clock: 6000 MHz (4x1500MHz)

Cooling
Cooling Type: Active

TDP
Idle: 15W
Idle ZCP mode enabled: 3W
Maximum load: 250W

3D API
DirectX version: 11.1
OpenGL version: 4.2
OpenCL version: 1.2

Dimensions
Slot Width: 2 Slots
Profile: Standard profile
Card Size: 268 x 122 x 36 mm

Weight
Card Weight: 698 grams

Output Configuration
DVI: 1x Dual-Link DVI-I
HDMI: 1x version 1.4a
Mini DisplayPort: 2x version 1.2
HDCP ready: YES
RAMDAC: 400MHz
Maximum Resolution analog: 2048x1536 (via Dual-Link DVI to VGA adapter)
Maximum Resolution Single-Link DVI: 1920x1200
Maximum Resolution Dual-Link DVI: 2560x1600
Maximum Resolution HDMI 1.4a: 4096x3112
Maximum Resolution Mini DP 1.2: 4096x2160
Maximum Outputs Simultaneously: 4

In the package
Club 3D Radeon HD 7970 royalAce graphic card
Club 3D CrossFireX bridge (CAC-CB) interconnect cable
Club 3D knob hanger
Driver & E-Manual CD
Quick install guide


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