Ouya, Surface and Nexus 7: The Rise of Tegra 3
Is NVIDIA's processor the best fit for a new tablet or console launch? Digital Foundry investigates
NVIDIA is in the ascendant: both Microsoft and Google have utilised the graphics specialists' Tegra 3 mobile processor for their new tablets, while newcomer Ouya is also based around the same technology. In effect, Tegra 3 is being positioned as a powerful, cost-effective challenger to the A5 and A5X chips in the iPad products, while at the same time being expected to power a $99 HD console. Can NVIDIA's system on chip deliver?
Mobile technology is developing at a breathtaking pace. Leaving aside the quad core CPU component for a moment, Tegra 3 itself is said to offer around twice the graphics processing capabilities of its predecessor - achieved by doubling the amount of pixel shaders and increasing clock speed.
"Tegra 3 is a versatile processor, but lacks GPU power even up against the older iPad 2. NVIDIA's response has been to work with game-makers to optimise titles for the strengths of the processor."
However, the reality is that the core aspects of the architecture are somewhat out of date compared to some of the competition - the processor doesn't support unified vertex and pixel shading capabilities and there's very much a sense that in its initial forays into its low voltage parts, NVIDIA worked mostly on the principle of transplanting across its older PC architecture into the mobile scene. This may explain why many benchmarks give the Apple A5 in the iPad 2 anything from a 30 to 100 per cent performance advantage: IMG's components were built from the ground-up with power efficiency and mobile performance in mind.
NVIDIA's response is to point towards real-world comparisons of the same games running on both mobile platforms. In setting up its TegraZone, NVIDIA has worked with developers to create bespoke versions of their games which feature graphical advantages to exclusive to their platform. Shadowgun, for example, features additional GPU effects, higher resolution artwork and animated clothing not seen on the iOS version, but it does take a hit to frame-rate in comparison to the same game running on iPad 2. Sonic 4 Episode 2 also features a range of graphics effects exclusive to the TegraZone version of the game.
Even in the normal Android ecosystem, there are some intriguing differences. GTA 3 has locked graphical presets on iPad, but allows for PC-style customisation on Android - where there are so many more hardware platforms to accommodate. Once again there can be a frame-rate hit in certain situations, but an Asus Transformer Prime tablet running GTA 3 on max settings features considerably more detail in the environments compared to the game running on the latest iPad.
One area where Tegra 3 maintains an undoubted advantage is in terms of CPU power. Apple's dual core 1GHz configuration falls short compared to NVIDIA's quad core set-up, both in terms of the amount of processors and maximum clock speed. NVIDIA even has a fifth "companion" core in there for low-power applications: this handles background tasks while keeping the major power-draining processing components offline. It is worth pointing out that mobile games rarely scale beyond two cores, so we don't often see much in the way of a performance boost from the quad core set-up during gaming, but the Android OS definitely benefits from it.
The overall conclusion is that Tegra 3 is somewhat behind IMG's PowerVR technology in terms of gaming, but the differences in benchmarks do not translate into the generational leap in graphical ability you might expect. NVIDIA's chipset may not be a market leader, but it is a worthy competitor in the current mobile generation, clearly capable of some good-looking games. Obviously they're some way short of the Xbox 360 and PS3 - even PlayStation Vita is a step beyond what Tegra 3 is capable of - but then, gamers aren't expected to pay £30 or more for mobile titles.
"The main concern with Tegra 3 is that with the shift to 28nm processors, products like Microsoft Surface could find themselves comprehensively outgunned by rivals released just six months later."
However, the rise of Tegra 3 is perhaps arrving a little too late in the day. It's a 40nm processor that's ripe for replacement, and tablets using it will face an enormous new challenge early next year in the form of competitors running on the 28nm fabrication node. NVIDIA's processor offers a similar "real-world" experience to the 2012 iPad, albeit running on lower resolution screens, but the fact is that Microsoft Surface launches around six months before a new Apple tablet that should - in theory - revolutionise mobile graphics technology.
The shrink to 28nm allows for many more transistors to fit onto the same area of silicon while drawing around the same amount of power, and major mobile technology vendors are ready for the leap in power this represents: ARM has its A15 processor ready in the wings, while IMG's PowerVR Rogue technology should finally see current-gen console performance in the mobile form factor. Sony has already licensed both of them for its upcoming range of NovaThor SoCs due at the end of the year. NVIDIA itself has a hugely exciting roadmap of technological advancement too - Tegra 3 offered a 2x advantage over its predecessor. It's believed that the forthcoming "Wayne" processor has something close to a 10x boost compared to Tegra 2. In short, mobile should exceed current console capabilities in 2013 - and continue to improve year on year. Speaking with Digital Foundry, IMG confirmed that it is looking at a 100x increase in GPU power in just five years.
The issue we see with Surface then is very much that it is a brand new product launching on a mature platform at a time when competitors will be months away from integrating far more powerful processors into their new tablets. This is far less of an issue for the Google Nexus 7 - where the price-point is paramount, and where the presence of a processor as powerful as Tegra 3 is simply miraculous in the first place. By Google's own admission, it is effectively selling the slate at cost price.
So where does this leave the hugely controversial Ouya? Well, take a look at the videos on this page. The notion of a $99 console running titles of this quality is obviously a very, very good thing. A lot of the arguments against Tegra dissipate when you see how much gaming value you're getting for such a low price. However, the console faces many challenges.
For starters, the notion of a $99 price-point has to be viewed with a certain amount of scepticism, as noted by the the Pandora project's Craig Rothwell, a man who helped write the book on creating an open source games platform from the ground up using mobile parts. The hardware being proposed is essentially identical to the Nexus 7: strip out the IPS screen and battery, replace with a bespoke joypad and the notion that this can be achieved at half the price seems to be somewhat optimistic, especially bearing in mind that Asus (Google's hardware partner) will have access to supply chains and mass volume discounts that Ouya with its limited production run can only dream about.
Tegra 3 will be a significant part of that $99 - but perhaps by next year, the chip will be cheaper than it is now: NVIDIA is committed to a 28nm die-shrink of the processor that should be more power-efficient and cheaper to produce. But even then, it's difficult to conceive just how Ouya can reach this price-point factoring in the kinds of materials and parts it is using, plus the fact that Kickstarter itself will be taking its fees from that $99.
The utilisation of Tegra 3 itself also limits the scope of what this open platform can achieve. When we imagine what console gaming is all about, there are inevitable comparisons to Xbox 360 and PlayStation 3, but the fact is that Tegra 3 is an older mobile part with nowhere near the horsepower found in existing machines. DICE rendering architect Johan Andersson describes Ouya as "severely underpowered… and constrained to Android ARM games."
"I would rather see Ouya with [a] much more powerful AMD Fusion Trinity x86 chip in it to also enable ports of PC and current-gen console games," he continued, later expressing hope that the makers of Ouya would transition the project across to a 2013 smartphone GPU - presumably for the same reasons.
"A $99 Tegra 3 powered console would be a miracle, but even if it meets its ambitious launch date, it could find itself challenged by a $149 Xbox 360 in a matter of months - and what if the next AppleTV runs games?"
Tantalisingly, Ouya is just one GPU generation away from being competitive with current-gen console, but any such improvement to the base spec (or indeed a shift to Trinity as Andersson suggests) would make the $99 price-point shift from implausible to impossible in the short term. The videos on his page demonstrate that Tegra 3 can produce some lovely games in the here and now, but products based on this technology could well see their gaming shelf-lives limited. This is not so much of a problem for a device where gaming isn't its primary purpose - but for a fixed platform like Ouya, facing the combined might of Sony, Microsoft, and potentially Apple, this could be a genuine concern.
Putting back the release date to accommodate an improved processor would make life for Ouya even more difficult: the price of the current-gen consoles will continue to tumble in the run-up to the release of next-gen replacements next year, and Ouya simply can't compare with the library of titles enjoyed by the Sony and Microsoft platforms. A $99 Ouya looks like unbeatable value, but up against a $149 Xbox 360? That could well be the decision facing the consumer by the time it finally comes to market.
Ouya will talk up its open platform claims - but it's content and functionality that counts, and of all the question marks that surround the new console, these are the major concerns - where are the games going to come from? Beyond gaming, what can it do? At the time of writing, developers don't have Ouya hardware, so what exactly will be available at launch next March - a selection of Android ports you can play with a joypad? Most suitable Android games already support the joypad anyway.
Beyond that, what the developers of the fledgling console must surely be dreading is any kind of move from Apple to reposition the AppleTV as a games-capable platform. The current model features an A5 graphics core just like the iPad 2 (albeit with some elements of the SoC disabled), and if Ouya proves that there is a viable market at the $99 price-point, a revised AppleTV could outquaff the new launch in every way, from content to processing power to developer support. The ability to pay just once for a game and play it at home and also on the move also introduces an additional layer of value too.
NVIDIA deserve credit for what it has achieved with the Tegra platform. From uncertain beginnings (including the loss of a deal which would have put the tech into Nintendo 3DS), it has emerged as the supplier of choice for the most high-profile Android products, and it looks set to dominate Windows 8 hardware too. But Apple has set the pace for the advancement of mobile technology and it's clear that NVIDIA and indeed the rest of the industry - Microsoft and Google included - are still playing catch-up. But with the upcoming transition to 28nm processor technology, there's everything to play for...