I'm sure I'm not the only person looking forward to AMD's Mobility Radeon HD 4000 graphics processors wending their way into notebooks everywhere. I'm currently in a curious position where I'm shopping for a laptop I don't necessarily need, because once I graduate from college this quarter, I may not have much use for one anymore outside of the odd trip. And let's face it: when you're a mild agoraphobe, trips aren't exactly common on your "to do" list. Yet I can't help but be excited about the 4000 series hitting the market.
To be honest, the transition to DirectX 10-class hardware seemed to lower the bar for Nvidia's mid-range GPUs. In the generations leading up to the G80, every mid-range Nvidia part was more or less a top-of-the-line GPU chainsawed in half. The GeForce 6600 GT was the first eight-pipeline part to hit that market, and it was able to run Doom 3 at 1600x1200—an impressive feat at the time. The GeForce 7600 GT wound up being so powerful that it performed eerily close to the 7800 GS, and as a former 7600 GT owner, I can tell you it was a monster for its time.
Then the GeForce 8600 GT and GTS came along and were met with a collective "meh." Maybe Nvidia was tired of mainstream hardware cannibalizing its high-end parts, but the G84 was a smaller slice of the G80 than some were expecting, and its performance often fell below the previous generation's performance-class hardware. Meanwhile, AMD struggled with somewhat mediocre Radeon HD 2600-series offerings (and, before those, the unremarkable Radeon X1600 lineup).
So why the history lesson? Because AMD and ATI's missteps seem to have hurt the mobile market by letting Nvidia get away with slower mainstream products. ATI mobile hardware suffered a steady decline after the Mobility Radeon 9600 (which dominated the market during its time), and only with the Mobility Radeon HD 3000 series did AMD manage to offer somewhat compelling performance. With little competition in sight, the G84 became Nvidia's high-end mobile GPU. For how mediocre Nvidia's current mobile hardware is, though, the 3000 series is often worse. G84 and G96 (essentially two sides of the same coin) derivatives run amok largely because of how middling the Mobility Radeon HD 3650 is. And now, nearly two years after the G84's launch, the best we've got is an underclocked GeForce 8800 GT. That's the mobile top of the line. It really doesn't get any better than that.
This is why the Radeon HD 4000 series is so important. The desktop HD 4670 doesn't trail the GeForce 9600 GT and 9800 GT by very much at lower resolutions, and the RV730 is a much smaller chip with a smaller power envelope. When it finally lands in notebooks, there's a very good chance that even its underclocked, mobility-optimized flavors will be competitive with GeForce 9800M-series GPUs. And AMD gambling on a smaller, more efficient die over a larger one may very well pay off. While the GTX series is simply too much chip to fit into a mobile chassis right now, AMD will be fitting the more svelte RV770 into desktop replacement notebooks across the land (assuming they nab the design wins, which they very well could).
Even better, while we still can't fit a full 128-SP G92 into a laptop (remember, the 9800M GTX is essentially an underclocked 112-SP 8800 GT), the RV770 will be making the transition with all 800 stream processors intact. Finally, a low-end market that's essentially being cannibalized by strengthening integrated graphics will once again be able to justify going with a dedicated low-end GPU, since the HD 4350 and 4550 are both capable enough parts for the casual gamer, with the 4350 essentially doubling the performance of its predecessor and anagram, the 3450. When you realize that the HD 3450 and 3470 are two of the fastest low-end mobile GPUs currently available, you can get excited even about these entry-level parts.
The Mobility Radeon HD 4000 series will hopefully force Nvidia out of its complacency, and the Mobility Radeon HD 4670 stands to be an outstanding contender for 15.4" notebooks, allowing mobile gaming platforms to advance again. My upcoming review of MSI's GX630 laptop, which carries a GeForce 9600M GT with 512MB of GDDR3 RAM, should be proof enough of how poor mobile gaming is right now. When a GPU that can barely handle Enemy Territory: Quake Wars at 1280x800 (settings maxed, antialiasing off) constitutes mainstream mobile gaming hardware, something is seriously off. The HD 4600, if the performance of its desktop cousin is anything to go by, could very well change this paradigm and push things forward.
While I can't get too excited about the Mobility Radeon HD 4800 line (large gaming notebooks are, in my opinion, just massive sinks of money), the possibility of enjoying a Radeon HD 4600-series chip in a 15.4" notebook is exactly the kind of thing that makes me keep an eagle eye on the future of laptops—and if I wind up going to grad school, I can almost certainly see one of those in my future. If AMD can get these out to manufacturers in quantity and pull off another coup in the mobile market the way it did with the desktop HD 4000 line, the next few months may be happy ones indeed for mobile gamers.