AMD's Hondo Z-Series APU To Challenge Intel's Atom In Windows 8 Tablet Market

AMD is launching its first tablet-optimized APU today, in a bid to challenge Intel's de facto dominance of the Windows 8 tablet market. Dubbed Hondo, the new Z-60 draws less power than any Brazos-based part AMD has launched before.

Some of you may remember that AMD launched a tablet processor last year, but the Z-01 -- codenamed Desna -- was an ordinary Brazos core that binned well enough to run within a lower power envelope. It was more a proof-of-concept chip, meant to demonstrate that AMD could, and would, compete in the tablet market. Hondo, in contrast, is a new spin on the original Brazos design. AMD took its first-generation APU and removed all the I/O blocks that a tablet wouldn't need, and optimized the chip's layout to target an even lower thermal dissipation envelope.

Re-architecting the chip has paid off. Like Desna, Hondo pairs a dual-core 1GHz Bobcat processor with an 80-core Radeon GPU at 276MHz. Video decoding is handled by UVD3, and the chip is powerful enough to handle 720P decode seamlessly.

Power consumption, however, is much improved. The original Bobcat had a 9W TDP, Desna managed 5.9W, and Hondo comes in at 4.79W, tops. AMD's documentation implies that consumers should see a real-world TDP of 3.9 - 4.5W.

Competitive Positioning

The top question for AMD's investors and enthusiasts alike is whether or not this new chip will gain traction in the market or slip into the ether. Direct TDP comparisons between AMD and Intel are useless; the two companies measure-up differently. Intel builds Clover Trail on a 32nm process, compared to 40nm for Hondo, but CPUs no longer account for the clear majority of handheld device power consumption. Display technology and wireless radio design both comprise a significant difference on phone/tablet battery life, more than enough to obviate the CPU-level difference in TDP.

Ever since it launched, Brazos has had a reputation for outperforming Atom by 15-20% clock-for-clock, but that may not be enough of an advantage in the tablet market. With Clover Trail, Intel has managed to keep Atom's burst clock speed at 1.8GHz, though it's known that the chip doesn't stay at that clock speed except when necessary. AMD, in contrast, has noted the Z-60's clock speed at 1GHz, without any mention of turbo clock mechanisms.

The question of which chip is faster will almost certainly depend on the thermal dissipation capability of the chassis and how aggressively Intel and AMD tune their power management. If the dual-core Atom Z2760 can run at 1.8GHz for a sustained period of time, it should outperform a pair of 1GHz Bobcat cores; the clock speed gap is likely too great for the Brazos-based APUs to overcome. Questions like this will ultimately be decided in how manufacturers choose to balance weight, fan noise, and system price points.

The Great Windows 8 Question

All the comparisons of Intel vs. AMD are themselves predicated on an even more important question: Do consumers want Windows 8 tablets at all? If the answer to that turns out to be "Not really," than all the spec battles in the world won't amount to much. Obviously Microsoft and Intel think people really do want Windows 8 tablets, and AMD's Hondo is timely, even if it's not a 28nm processor.

ARM, and the success or failure of Windows RT, could also threaten AMD's ability to secure design wins in the tablet space. Hondo's other task is to secure AMD's flanks from these attacks as well. This could prove difficult, given that companies like Qualcomm and Nvidia are talking about quad-core devices at 1.3-1.5GHz, and next-gen GPUs. AMD's dual-core Bobcat may well be faster than a quad-core A9, but the Windows 8 tablets in question will be powered by Qualcomm's Krait and the Cortex-A15. Both chips are built on 28nm, which leaves AMD at a significant die geometry disadvantage. Early price leaks on W8 devices implies that the x86 Intel versions are being priced well above the ARM tablets, but whether AMD will be able to claim the higher price bracket is again unclear.

That assumes anyone builds systems at all. Tellingly, neither AMD's presentation nor associated press releases mention a single SKU. The company says only that the new Z-60 is "shipping today to customers that are expected to launch systems later this year." Compare that to the plethora of systems Intel was showing off last week, and the difference is stark.

Jumping for Jaguar

Windows 8 could be the most transformative product to hit the PC industry since the advent of CD-ROM technology and the launch of Windows, and it'll take a few quarters to measure its effects. If it fizzles, AMD will have no trouble pushing back the launch of Kabini, Hondo's successor. If it takes off, Kabini's launch date becomes a matter of paramount importance.

AMD expects the Jaguar CPU at the heart of Kabini to deliver an IPC improvement of ~15% clock-for-clock in mainstream applications. Even in fully optimized code, Jaguar picks up roughly 6% and it's more efficient at power gating. Combined with a 10% clock speed improvement and lower overall power consumption, Jaguar would have a much better chance of matching Intel at the high end and the likes of Qualcomm and Nvidia further down.

If Kabini doesn't launch until this time next year, however, the window of opportunity will probably close again. By this time next year, Intel's 22nm Valley View is expected to be ready, with its quad-core, out-of-order Atom architecture. AMD, in contrast, hasn't said anything beyond "2013." Hondo is a solid step forward on the road to building the kind of SoC's AMD's CEO Rory Read has said that he's targeting, but the company needs a 28nm low-power architecture to have any hope of competing with future ARM or Intel products.