Intel Banias Additional Details
Posted 8/23/02 at 6:44 am by Anton
Intel continues to push their code-named Banias processor among the notebook makers, as this Japanese web-site reports. At the moment, the microprocessor giant supplies its partners with A1 stepping of its brand-new mobile CPUs. I remind you that beginning from the first quarter, Intel was sampling A0 version of Banias and we were able to see a system based on it at CeBIT 2002. Although the word about Banias was spread long ago, until now, we had no detailed information about this newcomer. Fortunately, Japanese observers managed to find-out really shocking details about this CPU.
The Banias processor is intended for use in mobile computers only and its architecture is totally different from that of the Pentium 4 processor. The die-size of 0.13 micron Banias is just 100 square millimetres compared to 131.4 square millimetres of Pentium 4-M (Northwood) CPU. It is simply amazing if we consider the fact that the former has 1MB of L2 cache. In case we assume that SRAM cell size of Banias and Pentium 4-M is the same and keeping in mind that 512KB of L2 cache in Northwood takes up about 20% of the core-size, we can conclude that L2 of 1MB in Banias will occupy more than 50% of its die-size. As a result, there is far less space for the L1 cache and processing logic itself in the new mobile processor compared to its predecessor. This fact again makes us think that Banias has pretty little in common with the Pentium 4 architecture.
Due to extremely small size of processing logic in Banias processor, the heat dissipation of the newcomer will be comparatively low. For instance, TDP (Thermal Design Power) of Pentium 4-M 2.4GHz is about 35W in performance mode and 20.8W in battery mode when the CPU works at 1.2GHz clock-speed. TDP of Banias processors functioning at 1.6 and 1.7GHz is just about 24.5W, while TDP of Pentium 4-M at the same frequency is about 30W. The advantage of Banias architecture is even more impressive if we remember that core voltage of the next-generation mobile processor is 1.35V compared to 1.3V of Pentium 4-M.
I also want to attract additional attention to the economical mode of Banias CPU. Pentium 4-M in battery mode can only work on two fixed clock-speeds, for example, Pentium 4-M 2.4GHz can function either at its nominal frequency or at 1.2GHz. Banias CPU at 1.6GHz can dynamically choose between various stages from 1.6GHz to 600MHz. At 600MHz, Banias works at 0.85V core voltage.
It is very important that architecture efficiency of Banias processor is so high that 1.6GHz model will offer the same performance as Pentium 4-M 2.2 or even 2.4GHz does! Considering that according to the current estimates, Banias based performance notebooks will be able to work 50% more time compared to current models based on Pentium 4-M without recharging the battery, this CPU will be one of the best performance/power consuming solutions around.
By the end of 2003, Intel will shrink the Banias to 0.09 micron process adding another megabyte of L2 cache. Analysts believe that since L2 cache circuits do not consume a lot of power, while the processing logic takes up very little die-size, Dothan code-named CPUs with 2MB of L2 will not need active cooling systems at all.
Banias will appear in the early 2003 in 1.6GHz, 1.5GHz, 1.4GHz and possibly 1.3GHz versions. Low voltage (LV) and ultra low voltage (ULV) models will also make their appearance with 1.1GHz and 900GHz clock-speeds accordingly. The processors utilise the same FCBGA package as Pentium 4-M, but some pins are a little different, presently making it impossible to develop a universal platform for both. At first, Banias processors will be quite expensive, hence, the lower-end notebooks will still be based on mobile Celeron processors.
Additional information about this admirable mobile CPUs will be available in September and October during two large events: Intel Developer Forum and Microprocessor Forum.
