Nvidia explains why Tegra 4i uses ARM Cortex-A9
The Nvidia Tegra 4i uses ARM Cortex-A9 architecture instead of the newer Cortex-A15. We asked Nvidia on why it did this
Nvidia is in attendance at MWC 2013 and Know Your Mobile caught up with the chip-maker to discuss its new Tegra 4i quad-core chip with integrated 4G LTE modem.
We asked Nvidia representative Sridhar Ramaswamy, senior technical marketing manager, why the Tegra 4i uses current-gen Cortex-A9 architecture when the Tegra 4 uses next-gen Cortex-A15.
He explained that Nvidia’s reasoning is two-fold. Firstly, by using the Cortex-A9 architecture for the Tegra 4i, Nvidia is able to get everything working on a smaller die, meaning the processor can easily be fitted to a wider variety of devices of varying sizes. It’s also cheaper to implement than the new Cortex-A15, a cost saving which funnels down to the end user.
These factors means greater market penetration at the level Nvidia wants to pitch the chipset – that being your average smartphone user and those who want 4G.
Ramaswamy said you can expect to see Tegra 4i handsets retailing for around the £200 mark, so that’s mid-range HTCs and the like.
The full-blown Cortex-A15 Tegra 4 will, for the moment at least, remain the territory of the high-end hardware, particularly devices aimed at fast 3D gaming.
Manufacturers wishing to leverage this extra power will, presumably, need to incorporate separate 4G modems.
The other reason Cortex-A9 is used in the Tegra 4i is that this isn’t your common-or-garden Cortex-A9. Ramaswamy said Nvidia has a very close working relationship with ARM and the result of this is some extensive tweaking to the core architecture.
He said the Tegra 4i can get a 30-40 per cent performance boost over competing Cortex-A9 hardware and is only around 10-20 per cent less powerful than the Cortex-A15 quad-core Tegra 4.
It’ll certainly be interesting to see the first wave of Tegra 4 and Tegra 4i devices to hit the market duking it out with Qualcomm’s Snapdragon 600 and Snapdragon 800, as well as new offerings from Intel, Samsung and ST-Ericsson.