Why not a Radeon HD 5870 X2? Specification discussion
A 1GB frame-buffer is allotted to each GPU, so the overall situation is effectively like having two separate GPUs, complete with memories, combined via CrossFireX. The obvious difference here is that it's accomplished on one single-PCB card via a PCI-Express 2.1 switch.
Remember SidePortX, the unused GPU-to-GPU interconnect on the HD 4870 X2? It's now been shelved because AMD reckons the new PLX switch has enough bandwidth for inter-GPU communication.
It's generally accepted that a graphics card needs to pull <300W under load. The twin-GPU Radeon HD 5970 manages that, just, and retains excellent idle board power characteristics - a hallmark of the 5000-series cards. The quoted 42W power-draw when idling is impressive for a top-level card.
Eagle-eyed readers may be wondering how the twin-GPU card only consumes 15W more than the single-GPU Radeon HD 5850 when in an idle (2D) state. This frugal increase lies with the driver putting the second GPU to 'sleep' when running 2D apps. Powering down to an almost-off state saves around 20W.
Why not a dual Radeon HD 5870, then?
We reckon that AMD could have launched this card with two GPUs working at HD 5870 speeds. The reason for not doing so explains itself. This card needs to beat out, without question, the GeForce GTX 295, to be named the fastest graphics renderer in the world. That is its job; nothing more.
Now, when NVIDIA's Fermi arrives on the scene, we're sure to see super-clocked HD 5970s, made possible by better yields at TSMC. Further, the relatively low clocks enable partners to launch overclocked parts straight out of the gate - bringing differentiation to the extreme segment.
Specification summary
The new Radeon HD 5970 is a dual-GPU card that uses the HD 5870 specification allied to HD 5850 speeds. This means it is the fastest single-card solution released by AMD.
In terms of cost, we're being informed that partners should be releasing limited-quantity models at between £400-£450, including VAT, although launch-day pricing will most likely be higher.
Let's take a closer look at the beast.
