View topic - AMD Radeon 7970 Review
AMD continues the trend of holiday releases with the launch of the Radeon HD 7970. Naturally, the new 7970 is slotted to replace and improve upon the Radeon HD 6970. The question is how much better does it perform, and what new features does it bring to the table. Earlier in the month I was invited to a Tech Day at the AMD Campus in Austin, TX. Unfortunately I wasn't able to attend. So, my knowledge on the technical details of the new architecture is a bit shallow. I will be meeting with folks at AMD in the new year to get a better understanding, and will follow up with a separate article then.
Until then, let's get into some performance details and look at what AMD is planning for the Eyefinity ecosystem in early 2012.
AMD is touting three "firsts" with the Radeon HD 7970. The first to a 28nm technology, the first to utilize PCI-Express v3.0, and the first with support for DirectX 11.1. While the move to 28nm pays immediate benefits in packing more transistors on the die, and lowering power consumption - the other two features will take time to be realized. For those who are interested in some of the architectural details, I've attached some slides below from the AMD press deck.
The Radeon HD 7970 ups the ante in almost every regard. It packs far more transistors onto the die, thanks to the 28nm process. Additionally, it ups the VRAM to 3GB, dramatically increases the shader count, and also increases the core clock. It does this for the same 250W profile of the Radeon HD 6970. Unfortunately, these improvements do bring a dramatically higher price.
|Card||GPUs||Transistors||Max Memory||Mem Bus Width||Shaders||Clock (MHz)||TDP (Watts)*||MSRP|
|AMD Radeon HD 7970||1||4.3B||3GB||384-bit||2,048||925||1375||<3||250*||$549|
|AMD Radeon HD 6990||2||2 x 2.6B||2 x 2GB||2 x 256-bit||2 x 1536||830||1250||37||350*||$699|
|AMD Radeon HD 6970||1||2.6B||2GB||256-bit||1536||880||1375||20||250*||$349|
|AMD Radeon HD 6950||1||2.6B||2GB||256-bit||1408||800||1250||20||200*||$279|
|*These values represent the maximum wattage allowed through the AMD PowerTune.
AMD estimates the average wattage draw for gaming is 190W/140W for the 6970/6950, respectively. Idle for the 7970 is based on a "long idle" scenario.
Long Idle & ZeroCore
One of the biggest updates with the new architecture is with idle power draw. Even with the massive improvements made over the last generations, the HD 7970 pulls off feats that will be hard to top. When additional cards reaches what AMD considers a "long idle" state, it idles at less than 3W of power. The fans actually stop completely reducing both heat and noise output.