If the Samsung Galaxy S4 follows in the same path as the S3, we should see two variants of the Android phone with different internals.
Like the S3, the international version of the S4 will likely carry Samsung silicon, while an LTE version in the U.S. opts for a Qualcomm processor.
While we won't know until Thursday what's inside precisely (and we may initially only know the precise specs of the international version), there are two candidates based on reports, including one from J.P. Morgan.
Whatever the case, there's no doubt the S4's high-resolution 5-inch class screen (possibly 1,920x1,080 resolution) will need plenty of horsepower to manage all of those pixels.
Samsung internals: It's highly likely that, like the S3 before it, the international version of the S4 will pack Samsung's newest chip from the Exynos line.
And there's one candidate that gets mentioned often. That would be the 8-core processor. Eight processor cores sound like a lot for a phone considering most Intel laptops only have two processing cores.
But the Exynos 5 Octa uses something called big.LITTLE. In other words, there are four "big" high-performance cores (up to 1.8GHz) and four "little" power-efficient cores (up to 1.2GHz), referred to as Cortex A15 and A7, respectively.
ARM, the chip's designer, describes the Cortex A15 as suited for "heavy workloads," like gaming, and the Cortex A7 for doing more mundane workloads, such as managing operating system activities.
And remember, being an ARM chip design, each individual ARM core hardly matches an Intel i7 core in performance.
Qualcomm internals: One candidate for the Qualcomm processor is the quad-core Snapdragon 600. The 600's cores can run at speeds of up to 1.9GHz and it is expected to also appear in LG's future 5.5-inch Optimus G Pro.
The Snapdragon 600, however, doesn't integrate a modem (though Qualcomm or another vendor can provide a 3G/LTE modem separately). For a Qualcomm quad-core chip, that won't happen until the LTE-capable Snapdragon 800, which won't be available commercially until much later. (And note the Galaxy S3's U.S. version used a Snapdragon S4 that did integrate a modem.)
This is all speculation of course but on the eve of the Galaxy S4's announcement, there's plenty of that going around.