A long time ago in a galaxy far, far away—last December, actually—AMD introduced the first members of its next-generation mobile GPU series: the Radeon HD 7600M, 7500M, and 7400M. As it turns out, those weren't really very next-gen at all, since they were based on the same 40-nm fab process and VLIW5 Terascale 2 architecture as, well, last-gen models.
Today, AMD has injected some actual newness in its mobile GPU lineup with the Radeon HD 7900M, 7800M, and 7700M. Code-named Wimbledon, Heathrow, and Chelsea, the new GPUs are fabbed on a state-of-the-art 28-nm manufacturing process, and they're based on the same Graphics Core Next architectural framework as the desktop 7000 series. And they have the same other niceties, like PCIe 3.0 support, AMD's VCE hardware video encoder, and ZeroCore power.
These are, in other words, truly deserving of the leading 7's in their model numbers.
Judging by the look of the packaged chips and their hardware specifications, I expect Wimbledon has a lot in common with Pitcairn (of Radeon HD 7850 and 7870 fame), while the other two new mobile entrants are probably awfully similar to Cape Verde (which powers the Radeon HD 7770 and 7750). Here's a detailed look at those specs:
|Radeon HD 7900M||Radeon HD 7800M||Radeon HD 7700M|
|Core clock||850 MHz||800 MHz||675 MHz|
|Memory interface width||256-bit||128-bit||128-bit|
|Memory||2GB GDDR5||2GB GDDR5||2GB GDDR5|
|Peak memory speed||4.8 GT/s||4.0 GT/s||4.0 GT/S|
|Peak memory bandwidth||153.6 GB/s||64 GB/s||64 GB/s|
The Radeon HD 7900M has the same unit counts and memory configuration as the desktop Radeon HD 7870; the only difference, as far as I can see, is that its core speed is a couple hundred MHz slower. The 7800M is similarly impared versus the Radeon HD 7770, and it's also had its memory speed curbed somewhat, from 4.5 GT/s to 4 GT/s (or 1125MHz to 1000MHz, if you're looking at the raw memory clock speed). As for the 7770M, that model has the same number of units enabled as the desktop 7750, but it's 125MHz slower, and it also runs its memory at 4 GT/s instead of 4.5 GT/s.
Not content with bringing over the finest silicon from its desktop family, AMD has given mobile users a little something of their own to brag about: Enduro, which can best be described as AMD's answer to Optimus. AMD says Enduro Technology automatically switches between integrated and discrete GPUs based on "application graphical requirements," and it claims the transition is "smooth" and "automatic"—just like with Optimus on Nvidia's mobile GeForces. The discrete GPU is also selected when the notebook is plugged in, and users can switch manually via the control panel if they so desire.
Best of all, AMD hasn't limited Enduro to its own platform. The technology is supposed to work with both Intel processors and AMD's A- and E-series APUs.
Laptops based on the new mobile Radeons are already here. In fact, AMD's Radeon HD 7970M GPU is featured as an option in the latest iteration of the Alienware M17x, right alongside Nvidia's new GeForce GTX 660M and 675M. The machine also packs a 17.3" display and a choice of Sandy Bridge-based Core i7 processors.
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