Nvidia has been offering sneak peeks at its upcoming Tegra ARM chip at trade shows and other small venues in recent months. However, as we reported earlier today, at CES 2014 in Las Vegas the graphics company finally unveiled its new Tegra. The chip previously codenamed Logan now has an official name, and it’s not Tegra 5 – this is the Tegra K1. Nvidia says it chose the name because this is not just a linear increase in the power of Tegra 4, it’s a massive leap forward. Not only does Tegra K1 mark the debut of a new GPU, this ARM chip will be the first 64-bit mobile processor from Nvidia.
Desktop GPUs come to mobile
All of Nvidia’s past systems-on-a-chip (SoCs) have been based on CPU architectures licensed from ARM and an ultra-low-power GeForce GPU. In the case of the Tegra 4, it has a 72-core GPU clocked at 672MHz. Tegra K1 boosts the count to a whopping 192 processing cores, but it isn’t just the number of cores that makes this GPU notable. The Kepler architecture used to build this GPU is the same one used in Nvidia’s current generation desktop graphics cards. That also means Tegra K1 will be the first mobile chip to support CUDA GPU computing and DirectX 11.
According to Nvidia, the Kepler-based GPU is more powerful than the graphics processors in the Playstation 3 and Xbox 360, and about 25-30 per cent as fast as the PlayStation 4 and Xbox One consoles. That might not sound impressive, but bear in mind this is a mobile GPU pulling a tiny fraction of the power used to run a console. The gaming potential of Tegra K1 is going to be one of Nvidia’s main selling points as evidenced by a major developer partnership announced at the event. Nvidia is partnering up with Epic Games to bring Unreal Engine 4 to Tegra.
Unreal Engine 4 (UE4) will soon be powering titles on the PC, Xbox One, and PS4. It supports an array of new rendering features like global illumination, realistic light scattering, and advanced particle effects. Epic Games founder Tim Sweeney said in a prepared statement that Tegra K1 will be capable of running upcoming UE4 games from PCs and consoles without issue. It took years for Unreal Engine 3 to reach mobile devices with Infinity Blade, but the wait could be essentially zero for devices running Tegra K1 later this year.
Nvidia goes 64-bit ahead of schedule
The move to a Kepler-based GPU was expected from Nvidia with the Logan chip, but the company announced something else that was only speculation before. The Tegra K1 will come in two versions where the CPU is concerned – one 32-bit and one 64-bit. The 32-bit chip will be released first with a quad-core Cortex-A15 CPU paired with a fifth low-power core in Nvidia’s 4-plus-1 configuration. This is similar to the design used in the Tegra 4 and many other ARM SoCs.
The 64-bit edition is shaking up Nvidia’s reported roadmap by swapping out the quad-core A15 for two Nvidia Denver cores. Project Denver is Nvidia’s custom CPU core based on the ARMv8 instruction set, but it was originally set to launch in the next version of Tegra codenamed Parker. This puts Nvidia in a position to get the first 64-bit chip into an Android device in 2014. Nvidia’s custom design utilising ARMv8 should also offer improvements in battery life over ARMv7.
Of note here is that the move to Denver CPUs will not include the 4-plus-1 core configuration. Nvidia originally implemented the fifth low-power core in Tegra 3 as an alternative to dynamic clock speed adjustments, which are not supported by ARM’s Cortex designs. Building the custom Denver CPU probably allowed it to better manage power consumption without resorting to extra cores. This is one of the benefits of licensing the ARM instruction set to create a custom core rather than simply using the Cortex reference designs. It’s the same thing Qualcomm has been doing with Krait and Scorpion CPUs in its Snapdragon SoCs for years.
The 32-bit Cortex-A15 version of Tegra K1 will arrive in the first half of 2014, but the more exciting Denver-based chip won’t reach consumers until sometime in the second half of the year. The plan right now is for both SoCs to have the same Kepler GPU, but a small spec bump is possible by the time the 64-bit version is out.