There’s bad luck brewing for the U.S. variant of the Samsung Galaxy S3, as it will reportedly not be able to be updated to Android 5.0 Key Lime Pie, which is expected to debut at next month's I/O Conference.

Variants of five Samsung devices are slated to receive updates to Android 5.0 upon its release, including the Galaxy S3, Galaxy S4, Galaxy Note 2, Galaxy Note 8.0, and Galaxy Note 10.1; however, the U.S. version of the Galaxy S3 will now likely be left out of the mix due to its lack of a quad-core processor.

Preliminary rumors reported by SamMobile announced the first class of Key Lime Pie updates as well as a number of devices that will likely see Android 4.2.2 Jelly Bean as their last update. The reasoning for the distinction was unknown at first, but now the tech website’s sources consider that lower-core processors are the smoking gun.

The list of devices expected to cease updates at Android 4.2.2 includes a number of mid-range devices as well older high-end devices, but most of those handsets contain dual-core processors, and some even single-core.

More current Samsung devices have been equipped with quad-core processors, including the international variant of the Galaxy S3, which contains the quad-core Exynos 4 processor; the U.S. version only contains the dual-core Qualcomm S4 Snapdragon chipset. With more powerful quad-core processors, it is likely that dual-core chips are now being phased out in order to make room for beefier devices. The Galaxy Note 2, Galaxy Note 8.0 and Galaxy Note 10.1 are similarly powered by the Exynos 4 Quad processor.

Samsung notably differentiates its Galaxy S series smartphone variants by processor type, with the international versions having twice as many cores but fewer gigahertz of power, while the U.S. versions have fewer cores but clock faster speeds. Nevertheless, chipsets with more cores are considered more powerful due to the simple concept of bigger is better: more cores overall exert more power.

The upcoming Galaxy S4 will also be equipped with more advanced processors with its international version containing the massive eight-core Exynos Octa 5 processor and its U.S. version containing the quad-core Qualcomm Snapdragon 600 processor. The device will ship with Android 4.2.2 Jelly Bean; as the 2013 flagship phone for Samsung, it will likely be a shoo-in for a prompt Android 5.0 update.

Gotta Be Mobile notes that there is no indication as to whether this cutoff for Key Lime Pie with quad-core processors originates from Samsung or from Google. If the quad-core policy comes from Google, we will likely see other manufacturers halt updates on their dual-core devices at Android 4.2.2, but this has not yet been confirmed. We propose there is no issue with devices updating from much older operating systems as the Galaxy Note 2 and Galaxy Note 8.0 both shipped with Android 4.1 Jelly Bean, while the Galaxy Note 10.1 shipped with Android 4.0 Ice Cream Sandwich. Though we suspect devices running Android 4.2 or later will have the most chance of receiving an update.

Recent reports suggest that the Google Nexus 4 smartphone will be the first device to receive Android 5.0 Key Lime Pie via an OTA update as Google tends to roll out its latest OS update on its most current Nexus devices within two weeks of release. The Nexus 4 contains a quad-core Snapdragon S4 Pro processor and also launched with Android 4.2.1, which definitely qualifies it for a Key Lime Pie update, but it is currently the only non-Samsung device slated to receive an update.

It remains unknown which devices will be the first to ship with Android 5.0; however, suggestions include the rumored Google Nexus 5 as well as various unreleased Nexus tablets, the elusive Motorola/Google X Phone and the Samsung Galaxy Note 3. None of these devices have confirmed specs, but the Nexus 5 is expected to contain the same quad-core Qualcomm Snapdragon 600 processor that will power the Galaxy S4 U.S. variant.

Android 5.0 Key Lime Pie will likely be unveiled at the Google I/O conference, which takes place in San Francisco from May 15 to 17 with a release date projected for June or July. Even if the U.S. Galaxy S3 doesn’t receive a Key Lime Pie update, its recent price slash to just $99 on AT&T, and likely soon on other networks, may keep its interest up for some time longer.