As it turns out, there has been a sudden increase in sales of the Surface series of tablets as Microsoft readies the release of its successor. The Surface Pro 4 is expected to be released in October with revenues for the series reportedly growing like never-before.

Quoting Microsoft's latest earnings report, Twice said, the Surface tablet lineup growth increased 117 percent, which translates to $888 million. This means, both Surface Pro 3 and Surface 3 tablets, launched in June 2014 and May 2015, respectively, have done very well. Overall, the full-year sales apparently improved 65 percent, topping $3.6 billion.

Meanwhile, Microsoft Chief Financial Officer and Executive Vice President Amy Hood said the Surface tablets were widely popular in the educational sector, Yibada reported. Hood said the success of the two-in-one tablets is predominantly because the device can double as a laptop with the optional keyboard in tow.

"Surface is clearly a product where we've gotten the formula right, earned fans, and can apply this formula to other parts of our hardware portfolio," Microsoft CEO Satya Nadella said. The Surface Pro 4 is expected to be pitted against Apple iPad Pro.

Tech Times said the Surface Pro 4 is slated to run Windows 10 straight out of the box. Plus, the slate will reportedly flaunt a 12-inch display, packed with a screen resolution of 2,000 pixels. The slate will be powered by an Intel Skylake processor and backed by 16GB of RAM.

When it comes to memory specification, the Surface Pro 4 is expected to come equipped with up to 1 terabyte of built-in storage capacity. To top it off, an advanced stylus and a USB Type-C port have also been tipped to be part of the upcoming Surface Pro 3 successor. Other optional accessories include a keyboard, Type Cover 3 and Docking Station, Yibada said.

Microsoft, however, has yet to confirm any specifications or features.