Apple was accused of employing a marketing gimmick recently, when it announced a new 64-bit processing core for the A7 ARM chip which powers the new iPhone 5S. The benefits of moving to 64-bit processing on mobile devices aren’t yet clear, but that hasn’t stopped other ARM chip makers from lining up to mention their own 64-bit plans.
Nvidia announced several years ago that it had licensed ARMv8 technology to build its own custom 64-bit core, and the time draws near when that endeavour will come to fruition. Tegra could finally be ahead of the pack.
All of Nvidia’s current and past ARM chips have used CPU designs licensed directly from ARM Holdings, which are then paired with Nvidia’s custom ultra-low-power GeForce GPU. Together these components make up the Tegra system-on-a-chip (SoC). Tegra 4 uses the fastest ARM-designed cores currently available – the Cortex-A15 – but even with these top-of-the-line cores Nvidia is at a disadvantage thanks to custom mobile CPUs.
Apple and Qualcomm both design their own CPU cores based on the ARM instruction set, which they pay a pretty penny to license. Apple stepped it up to the ARMv8 set with the Cyclone CPU core in the A7, while Qualcomm is still focusing on ARMv7 with the Krait 400 core (but it is expected to announce an ARMv8-based core soon).
It’s a lot of work to design a CPU core rather than just license one directly from ARM, but 64-bit is only the most recent example of how a custom core can help a company iterate and add new features. For example, Qualcomm’s custom chips can dynamically change clock speed on each core based on system load. Nvidia had to jury rig an extra companion core in Tegra to handle low-power tasks.
It’s believed that Nvidia started work on ARMv8 back in late 2010 or early 2011. If true, the company could possibly have samples of the so-called “Project Denver” 64-bit processing core ready in early 2014 as part of the Parker SoC. This is actually two generations past current ARM chips. Tegra 5 (codenamed Logan) is expected to hit devices in early 2014, based again on the Cortex-A15. Parker is supposed to be Tegra 6, but Nvidia could be in a position to move quickly towards this SoC and cut Tegra 5’s run a bit short. Although Parker was slated for a 2015 release the last time Nvidia spoke about it.
No one can deny that Tegra 4 is a much more competitive chip than Tegra 3 was last year, but Qualcomm’s custom Krait cores and quick design iteration have allowed it to nearly take over the Android device ecosystem. There are only a handful of devices announced with Tegra 4 chips, and one of them is Nvidia’s own Shield console. Meanwhile Snapdragon 600 and 800 power almost every high-end smartphone and tablet from 2013.
Over the last few years, Nvidia has no doubt poured many millions into Project Denver and the Parker SoC. Qualcomm is surely working towards a 64-bit chip down the road, but the company has been tight-lipped about future plans. The last thing Nvidia wants is for the market leader to beat it to ARMv8 with 64-bit. Whether or not 64-bit has real utility on mobile devices running 32-bit software, getting this right could set Tegra up for undeniable success, a distinction that has so far eluded it.