Texas Instrument has already announced OMAP5 series SoC. If you recall, there hasn't been a single OMAP4 based device released to the public yet, so TI is on fire as far as their production schedule goes. So how does OMAP5 compare against the competition?
Remember those days when Cortex A8 used to be the state of the art? The first Android phone to use Cortex A8 was the original Motorola Droid. Clocked at 600MHz, it massively overpowered anything else that was popular back then, which typically used 528MHz pre-Cortex (ARM11) based designs.
Then Cortex A9 came along, promising about 25-30% improvement over Cortex A8 at the same clock speed. On top of this, Cortex A9 based processors are dual-core, which promised another 100% improvement on top. Overall improvement of 2.5x over a single-core Cortex A8 was not out of reality.
Tegra 2, which was the first processor to hit the market with Cortex A9 design, proved this (see Smartbench Productivity Index score for Tegra 2 vs other phones). Texas Instrument's OMAP4 and Samsung's Orion/Exynos 4210 will also appear soon.
Now lets look at the Cortex A15 design.
TI claims their Cortex A15 design will be able to run up to 2GHz, and claims 3x the improvement over 1GHz Cortex A9 design! Since the clock speed is already twice as fast, we can safely deduce that each Cortex A15 core will bring in about 50% performance improvement over Cortex A9 at the same clock speed. Impressive!
Cache size matters
The original OMAP3 featured 256KB L2 cache. OMAP4 features 1MB L2 cache, shared between the two cores. OMAP5 is expected to feature 2MB L2 cache. This is especially important as OMAP5 uses the same dual-channel memory as OMAP4.
Interestingly, OMAP5 also features a pair of Cortex M4 cores as well. Cortex M4 is not built as a general purpose processor like Cortex A-series. It is unknown where this pair of cores can be used but some of the obvious areas include multi-media data processing and image processing.
This is another area where OMAP5 made huge improvement over OMAP4. OMAP4 features Imagination Technologies PowerVR GSX540 (the same one that was featured in Samsung's Hummingbird). Although pretty decent, a previous generation SoC matching the latest generation SoC is hardly impressive. So what did OMAP5 end up with? OMAP5 now features the latest SGX544 GPUs. SGX544 is designed to be used in multi-core form so it can be as powerful as what vendors wish. Unfortunately, we are still not sure how many core implementation OMAP5 will use. Even in a single-core form, there should be a significant improvement over SGX540.
OMAP5(Cortex A15) will be manufactured on 28nm. In comparison, OMAP4 uses 45nm. OMAP5 even running at 2GHz, should be relatively frugal when it comes to power consumption.
OMAP5(Cortex A15) can handle up to 4 cameras. Does this mean we can now have a font-facing camera along with a pair of cameras at the back for 3D images?
OMAP5(Cortex A15) features a deeper pipeline (15-24 stages) compare to OMAP4. What does this mean? OMAP5 will scale to higher clock frequency much more easily. We will probably see higher than 2GHz clock speed on these processors.
OMAP5(Cortex A15) features a 3-way out-of-order execution unit. This is absolutely a must for this architecture since deeper pipeline could potentially cause longer stalls without it.
ARM claims that a dual-core 32nm Cortex A15 will use less than half the power used by a 65nm Cortex A8 core (1st generation Snapdragons such as Nexus One and HTC Evo). Part of the reason is because the idle leakage numbers are about 1/4 of 65nm A8.
OMAP5 will go into production in Q3-Q4 of 2011 and phones using this SoC are expected to show up to the public about a year after that.
Here's some additional info on the ARM Cortex A15:
More details on Texas Instrument's new OMAP5 (OMAP5430,OMAP5432)
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