Microsoft's Windows Phone engineering team is currently testing the Qualcomm MSM8960 chipset, according to sources familiar with the company's plans. The dual-core 1.5GHz system-on-chip is undergoing tests to make it ready for at least one Windows Phone 8 handset due later this year. Qualcomm's Snapdragon S4 has been making waves recently thanks to its impressive performance in recent Vellamo benchmark results, beating Samsung's Galaxy S II and Motorola's Droid 4 by more than double. Microsoft is testing the chip to see if it can bring similar results to Windows Phone.

We are told that Sprint is interested in a potential Windows Phone 8 device running the MSM8960 and that it has shared its LTE specifications with Nokia. One source has suggested that the carrier may not introduce any further Windows Phones on its network until Windows Phone 8 is ready later this year. Sprint released its first Windows Phone, the HTC Arrive, in March last year and has not yet offered any new Windows Phone 7.5 handsets on its network. Although the testing of new dual-core chips is ongoing inside Microsoft, HTC is preparing to release the One S and an AT&T version of the HTC One X, both powered by the S4. With the rumored release date of Windows Phone 8 set for late 2012, Microsoft appears to be playing catch-up to enable Qualcomm dual-core functionality on its mobile operating system, but there's also the possibility of rival chipset support in future.

We asked Qualcomm about the potential of Windows Phone Snapdragon S4 devices and it dropped a hint that Microsoft could be testing its chipsets. Qualcomm's Rob Chandhok noted that the company's relationship is still "strong" with Microsoft, and that it has been "amazed" by Microsoft's use of the Snapdragon capabilities. When asked specifically about the dual-score S4, Chandhok told us to "ask OEMs about that" instead of Microsoft, adding that "there's no structural problem" to doing it. Microsoft has confirmed it plans to bring dual-core functionality to Windows Phone but it's still not clear how and when that support will come. Recently leaked information on Windows Phone 8 pegs multi-core support for next-generation Windows Phones later this year, tying in nicely with the company's testing of Qualcomm's S4.