In Theory: Can Wii U Offer Next-Gen Power?
Digital Foundry assesses what we know about the Wii U and what it tells us about the console's level of performance
It's been a week of measurements, comparisons and percentages. The next-generation Xbox will be six times more powerful than the 360, and 20 per cent more powerful than the Wii U. As for Nintendo's next-gen console, apparently that's packing twice the power of Microsoft's current offering. Meanwhile, as Digital Foundry recently revealed, Raspberry Pi's graphics core features 2x the performance of the SGX543 MP2 in the Apple iPhone 4S. Of all of the above, we strongly suspect that only one will actually be backed up by meaningful benchmarks (hint: it's the last one).
A Wii U that significantly outperforms current gen consoles would be wonderful, but the facts established to date suggest that 'power' isn't Nintendo's primary concern.
As for the Wii U and Nextbox figures, we're almost certainly as much in the dark as we ever were. One thing we really need to nail down straight away though is the concept of "power" and how it is measured - no actual metrics are attached to the rumours, essentially making the statements rather ambiguous but we'll assume they relate to processing and rendering performance. That being the case, the notion of Microsoft basing its next-gen machine around a £50 graphics core with low-end PC gaming performance only makes sense if it's planning to make the console exceptionally cheap from launch, with a Wii-style limited lifespan. Somehow, the idea of sustaining a console generation until 2020 and beyond with a Radeon HD 6670 seems somewhat improbable.
But what of the idea that Wii U is twice as powerful as the Xbox 360? It's the sort of story that we would really want to believe, but a look at everything we do know about Wii U suggests that it's not very likely.
So what are the facts at hand? Well, we know that IBM is providing the CPU, and we know that it's being fabricated at 45nm - the same process as that used for the combined CPU/GPU in the Xbox 360 Slim, and the core components of the PlayStation 3. We also know that AMD is providing the Wii U GPU, based on existing Radeon technology and featuring "high-definition graphics support; rich multimedia acceleration and playback; and multiple display support".
Crucially, we also know how big the Wii U is, and it's a hell of a lot smaller than either Slim rendition of the Xbox 360 and PlayStation 3. Why is this important? It's simple: typically, the more power you're packing, the bigger the case of the machine and the meatier its cooling assembly. Let's look at the respective volumes of the HD consoles in comparison with the Wii U, with the original Wii thrown in for good measure.
The PS3 is the biggest of the lot according to the graph - but it has a curved casing so actual volume will be lower, and of course, it's also packing an internal power supply. The really interesting comparison is the Xbox 360s up against the Wii U, both of which have external power bricks: we're seeing that Xbox 360s casing has around 2.6 times the volume of the new Nintendo console. The only real differences are that the 360 additionally houses a 2.5-inch hard drive and Wii U is almost certainly using a smaller, slimmer slot-loading drive compared to the more standard-sized unit in the Microsoft console.
Now, the latest Xbox revision is a good, reliable design - but it can still get very warm to the touch. So the question is simple: how can Wii U be twice as powerful as the Xbox 360 when it's got to cram in more advanced silicon with millions more transistors into an area that's tiny by comparison? Won't it overheat horribly? Where's the room for the substantial cooling assembly it would require?
In theory, we could look at laptops here as an example of getting powerful chips working in smaller areas. The problem here is that high-power mobile GPUs are highly 'binned' - they're the pick of the production crop of processors destined for a broad range of different graphics cards. Mobile parts are typically the very best chips, the cream of the crop, capable of great performance at low voltages. Nintendo would not have this luxury on a mass-production item with a single design, where high efficiency is the key to keeping costs down as much as possible.
Realistically, short of a major architectural shift to components based on smartphone tech - and lots of it - the idea of Wii U possessing next-gen rendering capabilities doesn't make a lot of sense. We know that there's no transition to mobile tech because the IBM CPU is an off-shoot of an existing line and the firm doesn't make mobile CPUs. Similarly, while AMD has produced smartphone GPUs, none of them get close to the performance of the Xbox 360's Xenos GPU. That being the case, the chances are that it's a customised variant of an existing PC Radeon part: Japanese sources have previously hinted at a connection to the Radeon HD 4000 series - and a lower-end chip from that range would be a good fit.
With the IBM chip confirmed at a 45nm process - the same as the current Xbox 360 - the question then moves on to how the graphics chip is made. TSMC, the most probable candidate for actually producing the chip, has just moved onto a 28nm process, and will be ramping up production throughout the year. But any new node typically starts with low production yields, so Nintendo would need to either swallow the cost (Microsoft did this at the launch of the 360 with the then state-of-the-art 90nm Xenos GPU) or downclock the chip. It's far more likely that sticking to the existing, established 40nm process for AMD GPUs would actually be cheaper for them in the short term - and would provide cost-savings in the future when the chip could be shrunk economically.
RAM and flash storage prices have plummeted in recent years - it's in these areas that we expect the Wii U to offer an advantage over the PS3 and Xbox 360.
But let's assume that Nintendo does push the boat out here. Even a 45nm CPU and a 28nm GPU in a box that small is still likely to cause cooling issues for an actual "next-gen" 360 beater. The more probable 45nm CPU/40nm GPU combo combined with the size of the machine suggests a far more likely scenario: that Wii U has a ballpark performance level with current PS3 and Xbox 360 titles, perhaps actually lower. Across the years, chip designs may have become more refined and efficient but it's worthwhile to point out that almost all major increases in processing power have mostly come from shrinks in the fabrication process meaning that more transistors can be packed into the same amount of silicon.
The final nail in the coffin about a notional 2x increase in power over the Xbox 360 comes from Nintendo itself. At no point has the platform holder ever suggested that Wii U offers that kind of leap in processing power, an extraordinary omission considering the amount of money Nintendo would need to invest in this architecture. The focus of the platform holder's message is of course on where the money has been spent: the tablet controller, with its zero latency link to the console - technology that must have been fairly expensive.
But is there anything in the package that could give the Wii U an advantage over the PS3 and Xbox 360, aside from the tablet controller? We should look at the commodities that have collapsed in price over the past few years, and could prove genuinely useful for a games machine. RAM is the obvious choice: a 1GB minimum wouldn't break the bank and would help developers significantly. The pre-E3 rumour of 8GB of flash RAM also makes sense, especially when we bear in mind that there is no internal hard drive. The Wii U optical drive - almost certainly based on Blu-ray technology - could also be faster than its PS3 equivalent too. This may be useful bearing in mind that the lack of HDD would preclude mandatory installs.
So the opportunity is there for Nintendo to capitalise on cheaper components and die-shrunk silicon, and those savings can account for the cost of the tablet controller and some nice bonus additions over the PS3 and Xbox 360 - but to actually double the processing power of the current gen platforms just doesn't seem to ring true with everything that's been revealed about the console thus far. There is talk of Nintendo "re-introducing" Wii U at E3 this year, and doubtless we'll be seeing some actual games from the launch line-up - but it's difficult to believe we'll be witnessing the arrival of a machine capable of the kind of next-gen rendering that outstrips the current consoles. A key lesson Nintendo learned with Wii is that the price-point of the machine at launch is crucial, and it's hard to imagine that it could bring in a massive performance boost and the innovative controller at a price attractive to the audience.
Nintendo's focus in recent years has been about concepts, not specs, and nothing about Wii U seen to date suggests any kind of change in strategy.