Over on Weibo, a poster claims Chinese smartphone vendor Xiaomi will unveil its next generation flagship phone, the Xiaomi Mi 5, on Dec. 3. This phone, per the supposed leak, could pack Qualcomm's (NASDAQ:QCOM) yet-to-be-released Snapdragon 820 processor, which the wireless chip giant hopes will strengthen its product portfolio.

That being said, a quick sanity check shows at least one portion of this rumor is probably false. If the Xiaomi Mi 5 features a Snapdragon 820, it will not be launching on Dec. 3. If the Xiaomi Mi 5 launches on Dec. 3, it won't feature a Snapdragon 820. Here's why.

When is the Snapdragon 820 going to become available, again?
Although Qualcomm is expected to formally "launch" the Snapdragon 820 chipset on Nov. 10 (I suspect this launch will consist of providing full specifications as well as some performance numbers), the company indicated on its most recent earnings call that sales of the Snapdragon 820 won't start having a material impact on the company's financials until the second half of its current fiscal year.

Given that the second half of Qualcomm's last fiscal year began on March 30, 2015, it is unlikely the company will be recognizing much, if any, revenue from Snapdragon 820 shipments until late March/early April 2016.

Although there is the remote possibility Xiaomi wants to preannounce a new flagship phone several months in advance, I don't think the timing of the Snapdragon 820 launch quite fits the rumored Mi 5 launch schedule. 

What might be inside of the Mi 5, then?
There have been rumors that the Mi 5 will be powered by the MediaTek Helio X20 and, frankly, given the specifications of the X20 I think the rumors are at least plausible.

The X20 is MediaTek's latest flagship mobile processor and, at least on paper, looks like a sizable jump in features and performance from the relatively dated Snapdragon 801 currently found in the Mi 4 phone.

In addition to a much faster CPU complex in the X20 relative to the Snapdragon 801 (peak CPU performance is probably up in the range of 70%), the X20 should also feature a higher performance modem (support for category 6 speeds, up from category 4 in the Snapdragon 801), more robust image signal processor (which should enable Xiaomi to do interesting things with its next generation camera subsystem), and much improved 3D graphics performance.

I don't think the Helio X20 will offer quite the level of performance that the Snapdragon 820 should be able to. However, the Helio X20 should be available sooner, allowing Xiaomi to release the device in December.

Where might we see the Snapdragon 820 in Xiaomi's lineup, then?
Earlier this year, Xiaomi launched the Mi Note and Mi Note Pro phones using Qualcomm's Snapdragon 801 and Snapdragon 810 processors earlier this year. Given the timing of the availability of the Snapdragon 820, I think it wouldn't be unreasonable to expect a Xiaomi Mi Note Pro using the Snapdragon 820 launch in the first half of next year.

I don't think Xiaomi will use the 820, which should be a relatively expensive part, in a next generation vanilla Mi Note. However, the Snapdragon 620 -- which should offer a big boost in performance over the Snapdragon 801 in the current Mi Note -- looks like it could be a good fit for such a device.

Ashraf Eassa owns shares of Qualcomm. The Motley Fool owns shares of and recommends Qualcomm. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.