AMD has taken the wraps off its latest A-Series Accelerated Processing Unit (APU) codenamed ‘Carrizo’, revealing it will offer a 40% drop in power consumption while providing “double digit” performance improvement.
Unveiled at the International Solid State Circuits Conference (ISSCC), the new chip is designed for use in notebooks and all-in-one desktops with its integrated graphics intended to eliminate the need for a separate graphics card.
This is also the first APU to have an integrated south bridge. This is normally a separate chip that deals with things like storage IO and audio, and by bringing it onboard it can offer energy efficiency gains as well as make it easier to design more compact devices. It also includes a dedicated h.265 video decoder for, in particular, hardware accelerated playback of 4k video.
Introduced by AMD Corporate Fellow, Sam Naffziger, he described Carrizo as delivering “the largest generational performance-per-watt gain ever for a mainstream AMD APU.”
Carrizo will offer 29% more transistors in nearly the same size chip as its predecessor ‘Kaveri’ despite not moving to a new smaller manufacturing process.
This means it's still stuck at 28nm while rival Intel has already moved onto 14nm after using 22nm for last year’s designs. With this being the case it's unlikely AMD's new chip will be finding its way into the latest ultrabooks but rather it'll be aimed at more mainstream systems where the integrated GPU power will be most appreciated.
The heart of the new chip is a new ‘Excavator’ x86 core which can handle increased instructions per clock yet uses 40% less power. Details on how exactly this is achieved have not yet been revealed but AMD has detailed a couple of power saving feature that affects the whole chip.
The first aims to reduce the need to over-voltage the chip to compensate for voltage droop. Instead of using a blanket excess voltage to compensate it analyses the required voltage to the nanosecond. This results in a power cut of 10% for the GPU and 19% for the CPU.
Another technology is adaptive voltage and frequency scaling (AVFS) which uses “silicon speed capability sensors” and voltage sensors in conjunction with more conventional temperature and and power sensors to adapt the APU’s behaviour in real time. This the company claims can lead to up to 30% power savings.
Carrizo will be arriving in products around the middle of this year.