AMD Radeon HD 7870 Five-Way Shootout


Introducing the AMD Radeon HD 7870

Introducing the AMD Radeon HD 7870

AMD's upper mid-range Radeon HD 7800 series, code-named Pitcairn, should find a wider audience than its top-of-the-line (and expensive) Radeon HD 7900 Tahiti range. Hitting the sweet spot between value and performance, but with a more affordable price point, this series almost doubles the power of the basic mid-range Radeon HD 7700 Cape Verde series. Due to the untimely launch of the Radeon HD 7800 series when a a boatload of other hardware were launched consecutively, we've given the market some time to flesh out more custom edition cards before we embark on a detailed look at it.

As can be expected, there are two editions to this series - the Radeon HD 7870 and the Radeon HD 7850. We'll be focusing on the former to see just how much does it differs from a true Tahiti class product (Radeon HD 7900 series) and should you consider it.

The Radeon HD 7870 utilizes AMD's Graphics Core Next 28nm architecture and comprises of 2.8 billion transistors packed into 1280 stream processors with a default clock speed of 1000MHz, which has led to AMD coining it as the GHz Edition. However take note that the 1GHz clock speed is the reference clock of this card and there are no special variants of it unlike the HD 7970 GHz Edition. As such, beware of the naming schemes employed and don't fall for the "GHz Edition" branding for this GPU series.

The GPU has 80 texture units, 128 Z/stencil units, and 32 ROPs in the Radeon HD 7870 - that's a 14% increase in stream processors and a 43% increase in texture units compared to the previous generation Radeon HD 6870.

Compared to the rest of AMD's GCN range, the GPU on the HD 7870 is nearly twice as complex as the basic mid-range Radeon HD 7770, which contains 1.5 billion transistors, and just under two-thirds the count found on the flagship Radeon HD 7970, which utilizes some 4.3 billion transistors. As such, you can tell that it's positioned closer to the Tahiti than the Cape Verde series.

Overseas, the Radeon HD 7870 retails for US$349, which hits a nice price-point, slotting into the middle of AMD's lineup between the US$399 Radeon HD 7950, and the US$249 Radeon HD 7850. AMD has also just announced price cuts to all 7000 series cards, which will see the HD 7950 fall to US$349, the HD 7870 to US$299, and the HD 7850 to US$239.

Locally however, things are a bit different. Due to the additional costs of importing, shipping, warranty and support for a finite group of DIY users locally, a reference-class Radeon HD 7870 retails for about S$490, while a reference Radeon HD 7950 has an RRP of S$559, but can be had for as low as S$518 (PowerColor) at the point of writing.

As for NVIDIA, the green camp has yet to release their mid-range Kepler-based card, the GTX 660 (rumored due date: mid-August), which should compete against the Radeon HD 7870. For now, price-wise, the previous generation GTX 580 is the closest competitor.

AMD Radeon HD 7870 and competitive SKUs compared

Model AMD Radeon HD 7870 AMD Radeon HD 7950 AMD Radeon HD 6970 AMD Radeon HD 6870 NVIDIA GeForce GTX 580
Core Code Pitcairn XT  Tahiti Pro Cayman XT Barts XT GF110
Transistor Count 2.8 billion  4.3 billion 2.64 billion  1.7 billion 3 billion
Manufacturing Process 28nm 28nm 40nm 40nm 40nm
Core Clock 1000MHz 800MHz 880MHz 900MHz 772MHz
Stream Processors 1280 Stream processing units 1792 Stream processing units 1536 Stream processing units 1120 Stream processing units 512 Stream processing units
Stream Processor Clock 1000MHz 800MHz 880MHz 900MHz 1544MHz
Texture Mapping Units (TMU) or Texture Filtering (TF) units 80 112 96 56 64
Raster Operator units (ROP) 32 32 32 32 48
Memory Clock 4800MHz GDDR5 5000MHz GDDR5 5500MHz GDDR5 4000MHz GDDR5 4000MHz GDDR5
DDR Memory Bus 256-bit 384-bit 256-bit 256-bit 384-bit
Memory Bandwidth  153.6GB/s 240GB/s 176GB/s 134.4GB/s 192.4GB/s
PCI Express Interface PCIe ver 3.0 x16 PCIe ver 3.0 x16 PCIe ver 2.0 x16 PCIe ver 2.0 x16 PCIe ver 2.0 x16
Molex Power Connectors  2 x 6-pin 2 x 6-pin 1 x 6-pin, 1 x 8-pin 2 x 6-pin 1 x 6-pin, 1 x 8-pin
Multi GPU Technology CrossFireX CrossFireX CrossFireX CrossFireX SLI
DVI Output Support 1 Dual-Link 2 x Dual-Link 2 x Dual-Link 2 x Dual-Link 2 x Dual-Link
HDMI 1 1 1 1  1 (mini-HDMI)
DisplayPort 1 (version 1.2) 2 (version 1.2 HBR2) 2 (version 1.2) 2 (version 1.2) None
HDCP Output Support Yes Yes Yes Yes Yes
Street Price (SGD) $490 $559 $484 $275

$509