Intel continues to stick to their “tick-tock” strategy. The current Ivy Bridge processor generation is a “tick”, which represents the transition of the existing microarchitecture to the new 22 nm production process. Therefore, Haswell will be a “tock”. It means that the production process will remain the same, using 22 nm technology and Tri-Gate transistors, but all engineering effort will be focusing on architectural modifications and enhancements. So, Haswell is a huge step forward in terms of changes in the processor logical structure. By the way, the launch of Haswell will also mark the arrival of a completely new platform.
Haswell represents an entire family of products, however the span of the family for Haswell is larger than the span we had for prior products. Last year at the IDF 2011 Intel talked about Haswell on a very high level. This time they revealed more details on how they were able to improve power and performance.
So, first let’s talk about the Haswell philosophy. Of course, the starting point was the Sandy Bridge and Ivy Bridge generation that came immediately before that. Turbo mode, ring interconnect, hyper-threading, etc. - all these features are carrying over to Haswell. Of course, Intel made some improvements to all of them, but the basics remained the same. When designing a product like Haswell, the converged core, namely a single microarchitecture that scales from tablet to server is important. These are the three major pillars in Haswell microarchitecture:
- Performance (legacy performance for software that already exists plus new performance);
- Modularity (span of the family);
- Power (power management and reduction).
Intel’s design philosophy that should be carried on into the next product generations implies that they will use unified design for multiple diverse applications, from servers to tablets. Intel managed to significantly lower the power consumption of the Haswell core, which allows for such immense design flexibility. Ultra mobile processors and tablet processors will have few cores and low frequencies and will be extremely energy-efficient. In the desktop segment they will be shooting for higher performance achieved due to larger number of cores and more conventional TDP. And the server segment will accommodate multi-core CPU modifications.
The modularity aspect implies that it is possible to create products that span across a very wide range of products. It is a great feature that is elevated to a completely new level in the new Haswell microarchitecture. Previously, Ivy Bridge and Sandy Bridge allowed to play around with rather few combinations of cores and two graphics core models. Now there will be more combinations available, at least because there will be minimum three graphics core modifications.
To give you an idea of what the new Haswell microarchitecture will be like, Intel singled out several major knobs that drive performance and industry adoption:
- How many cores will Haswell have? – On the client side there will be 2-4 cores.
- What will be new in terms of graphics? – Haswell can scale the amount of graphics computes, so that the performance could be scaled as well.
- What is the active power level? – Design points they had in the past are still there, but in Haswell they are adding lower power design points.
- What else drives performance? – The cache sizes in Haswell can be scaled, too.
- Finally, what the platform itself looks like? – The platform will be traditional but power optimized. Also, Intel will be proving a consistent developer environment, adding more agility. As they build product families, they will be able to design more specialized parts that will fit the specific demand even better. So, this collaboration is a result of special attention paid to the modularity aspect.
- And what about the microarchitecture itself? In fact, even though Intel did quite a bit of work on improving it, there is nothing principally new about Haswell. Actually, the entire foundation has been borrowed from Sandy Bridge and Ivy Bridge. In other words, they added some new features to the good old time-tested base, made a few optimizations here and there, and here we are – meet the new Haswell!