PowerColor Radeon HD 7950 PCS+ review

Specs and Southern Islands

Southern Islands

As weird as it might sound, we are going to talk about some islands first. And no it's not that I need vacation and have an urge to talk about islands in de sea. But you've been hearing about several codenames and that can be a little confusing. AMD codenamed their 6000 and 7000 product series after Islands in the northern (6000) and southern (7000) hemisphere.

It's simple really, in the market we have entry level, mainstream and high-end products. When you notice "Verde" that's entry level. Pitcairn is the codename the mainstream products hide under, and finally Tahiti is the codename for the most high-end products.

• Entry level = Verde = Radeon HD 7700 series
• Mainstream level = Pitcairn = Radeon HD 7800 series
• High-end level = Tahiti = Radeon HD 7900 series

The entire segment from top to bottom will be released in Q1 2012, today the second product series, the Radeon HD 7950.

Technology

We'll focus on the 7900 series today of course, but it is important to understand that there are significant changes in this Family of GPUs. The GPU architecture was overhauled, AMD moved towards a 28nm process technology, the new cards are PCIe gen 3 compatible and there have been significant changes on power consumption. We'll address all the features separately of course.

With the launch of the Radeon HD 7000 series you will also see Eyefinity updated towards version 2.0, DDM audio is now fully supported (you hear audio on the actual monitor it's played of), a new 5x1 landscape mode is introduced, and you may now create custom multi-monitor resolutions. But let's break things down.

Radeon HD 7950

AMD now bakes GPU's on the all new 28nm node, in very simple wording that means they can put more transistors on a smaller area. The Tahiti core has a stunning 4.3 Billion transistors, 4,312,711,873 to be precise.

The internal architecture has changed, we'll talk a little deeper about that in a minute. But as a result, the R7950 is packed with 1792 shader processors harbored in Compute Units segments (28 of them).

Memory volume wise the rumors where right, the card will pack a whopping 3 Gigabyte of DDR5 memory. This is not done for bragging rights, but AMD simply takes Eyefinity and multiple monitor usage very serious, that is where the extra memory makes a lot of sense. The memory bus has been increased from 256-bit towards 384-bit as well.

Packing so many transistors on a product is staggering, but if you can't apply a fast enough clock frequency it would become a problem. Well, that's not an issue for AMD either, the reference R7950 model is clocked at 800 MHz with room to tweak towards over a full GHz. That 384-bit memory is clocked at impressive speeds as well - 5 Gbps, that's bandwidth up-to 240 GB/sec (!).