AMD has certainly gone about doing things in a slightly different manner than we are used to. Today they announced their two latest APUs which will begin shipping in the first half of 2015. These APUs are running at AMD and are being validated as we speak. AMD did not release many details on these products, but what we do know is pretty interesting.
Carrizo is based on the latest iteration of AMD’s CPU technology. Excavator is the codename for these latest CPU cores, and they promise to be smaller and more efficient than the previous Steamroller core which powers the latest Kaveri based APUs. Carrizo-L is the lower power variant which will be based on the Puma+ core. The current Beema APU is based on the Puma architecture.
Roadmaps show that the Carrizo APUs will be 28 nm products, presumably fabricated by GLOBALFOUNDRIES. Many were hoping that AMD would make the jump to 20 nm with this generation of products, but that does not seem to be the case. This is not surprising due to the limitations of that particular process when dealing with large designs that require a lot of current. AMD will likely be pushing for 16 nm FinFET for the generation of products after Carrizo.
The big Carrizo supposedly has a next generation GCN unit. My guess here is that it will use the same design as we saw with the R9 285. That particular product is a next generation unit that has improved efficiency. AMD did not release how many GCN cores will be present in Carizzo, but it will be very similar to what we see now with Kaveri. Carrizo-L will use the same GCN units as the previous generation Beema based products.
I believe AMD has spent a lot more time hand tuning Excavator instead of relying on a lot of automated place and route. This should allow them to retain much of the performance of the part, all the while cutting down on transistor count dramatically. Some rumors that I have seen point to each Excavator module being 40% smaller than Steamroller. I am not entirely sure they have achieved that type of improvement, but more hand layout does typically mean greater efficiency and less waste. The downside to hand layout is that it is extremely time and manpower intensive. Intel can afford this type of design while AMD has to rely more on automated place and route.
Carrizo will be the first HSA 1.0 compliant SOC. It is in fact an SOC as it integrates the southbridge functions that previously had been handled by external chips like the A88X that supports the current Kaveri desktop APUs. Carrizo and Carrizo-L will also share the same infrastructure. This means that motherboards that these APUs will be soldered onto are interchangeable. One motherboard from the partner OEMs will be able to address multiple markets that will see products range from 4 watts TDP up to 35 watts.
Finally, both APUs feature the security processor that allows them access to the ARM TrustZone technology. This is a very small ARM processor that handles the secure boot partition and handles the security requests. This puts AMD on par with Intel and their secure computing solution (vPro).
These products will be aimed only at the mobile market. So far AMD has not announced Carrizo for the desktop market, but when they do I would imagine that they will hit a max TDP of around 65 watts. AMD claims that Carrizo is one of the biggest jumps for them in terms of power efficiency. A lot of different pieces of technology have all come together with this product to make them more competitive with Intel and their process advantage. Time will tell if this is the case, but for now AMD is staying relevant and pushing their product releases so that they are more consistently ontime.