The reasoning behind Mantle runs something like this: Historically, in terms of game graphics, consoles have been able to do more with less, because game developers were able to tune their code at a very deep level to the unchanging silicon architecture at the heart of each generation of machine. PCs, by contrast, did less with more: they had upgradeable silicon that tended to be more powerful, but they were held back by traditional, GPU-agnostic programming tools like DirectX and OpenGL. Finally, the argument goes, Mantle will allow PCs to do more with more, since it's a shallower API that gives developers better access to everything a cutting edge CPU and GPU has to offer.
Mantle would have been dismissed as craziness just a year ago, since AMD lacked the clout to put its own API forward. But now that the company effectively owns the next generation of console graphics, such that numerous developers may end up using Mantle-style code regardless of any explicit intention to snub NVIDIA, the new API starts to make a lot of sense. Indeed, every single one of AMD's new cards, as well as its existing Graphics Core Next (GCN) branded cards, has a direct familial connection to the silicon found in the PS4, Xbox One and (to a lesser extent) Nintendo's Wii U, thereby making it potentially capable of better graphics than its raw specs might suggest -- although we'll have to wait a while before we can put this to the test, for example with EA DICE's Mantle update for Battlefield 4 due in December.
4K and Eyefinity
Moving onto the hardware itself, AMD isn't quite ready to reveal full specs or pricing for its highest-end card, the R9 290X. This also happens to be the card with the newest silicon design, since lower cards are based on existing GCN architecture. However, we're guessing it'll be somewhere around the $500 RRP of the current flagship, the Radeon HD 7970. Regardless of the exact price, it's safe to assume that this card will be geared towards 4K (3,840 x 2,160) and triple monitor resolutions. To get around the frame-rate limitation of 4K over first-gen HDMI, AMD is pushing for a new VESA standard to make it easier to set up 4K displays that stitch together inputs from two separate HDMI cables. Meanwhile, the focus on Mantle, TrueAudio and the various display standards, along with a general reduction in dollars-per-FLOP in the Rx series, will cause older 7000-series cards to be phased out very abruptly -- so expect to see some wild discounts in the next couple of weeks. (But don't pick up anything less than a GCN card if you want to see what Mantle has to offer.)
The $299 mid-range
The R9 280X occupies the traditional "sweet spot" in AMD's line-up, promising good frame rates in current games up to 2,560 x 1,440. Tomb Raider is claimed to run at around 38 fps at this res, even with TressFX hair extensions enabled, versus 28 fps delivered by NVIDIA's GTX 760, based on AMD's official benchmarks. (A side note: TressFX 2.0 is on its way, which will allow the rendering of 12 thousands separate strands of hair in a single scene.) The underlying silicon in 280X is essentially a tweaked version of the GPU in the current Radeon HD 7970, with 2,048 stream processors that are capable of delivering up to 4.1TFLOPs of compute power and draining up to 250 watts of energy from the wall. The card also comes with the necessary 3GB of GDDR5 (with 384-bit bandwidth) to be recommended for use with Battlefield 4.
1080p gaming for $199
At the bottom of the R9-branded stack comes the 270X, which starts at $199 and is built to achieve playable frame rates at 1080p on the latest games. AMD's official benchmarks put it head-to-head with the GTX 660 and give it a 25-50 percent advantage in frame rates on games like Tomb Raider, Battlefield 3 and Hitman Absolution. The 270X has around two thirds as many stream processors as the 280X and hence around two thirds of the FLOPS, and it comes with 2GB of 256-bit GDDR5. Power consumption falls roughly in proportion, down to 180 watts. Noise is also a big deal with cards in this bracket, and AMD promises that its PowerTune feature now has much more control over the fan, allowing RPM to be adjusted smoothly over time rather than in distracting jolts.
Sub-$150 R7 cards
Finally, we come to the lower-priced segment that -- according to AMD -- constitutes 90 percent of the entire graphics card market. Working from top to bottom, the R7 range starts with the 260X at $139, which comes with 2GB of GDDR5, 896 stream processors, a clock speed of up to 1.1GHz and 1.97TFLOPS of max compute. This offer performance that is broadly equivalent to the Radeon HD 5870 from two product cycles ago, except with $250 taken off that old card's price.
Just like the R9 cards, this R7 comes with TrueAudio processing, enabling relatively accurate virtual surround sound within games that make use of the technology, as well as the playback of over a hundred separate voices instead of the 10-15 that is the norm in a lot of PC titles.
Next comes the R7 250 at just $89, which has half the performance of the 260X, burns just 65 watts and comes with either 1GB of GDDR5 or 2GB of DDR3 depending on the configuration. Memory bandwidth is 128-bit, so it'll be interesting to see how independent reviewers rate this card's ability to handle current games. These same memory configurations will also be found on the R7 240, which is a low-profile card aimed at HTPCs and other systems -- although it still needs a fan to dissipate its 30-watt power draw. This R7 240 represents AMD's cheapest card, with just 499GFLOPs of compute, although we don't have an exact price for it just yet.
That's about it for now. Official specs and benchmarks can only take us so far. Stand by for our round-up of independent reviews coming to these pages shortly.