Today's Tech: Microsoft Surface ad spending outweighs earnings from tablet sales and Samsung denies cheating in Galaxy S4 tests

Microsoft's sales of its Surface tablet have so far not even covered the company's advertising costs, according to a regulatory filing the company has made with the US Securities and Exchange Commission. The filing was ostensibly made to record the fact the company had earned revenue of $853 million (£561 million) in its fiscal year ending 30 June from the Surface tablet. The Redmond firm did not disclose how many units of the tablet it had shipped or sold during the year though. Earlier this month Microsoft took a charge for Surface RT inventory adjustments of around $900 million (£592 million), so that charge didn't even cover its Surface sales for the year ending June. In addition, the company also said its advertising costs increased by $898 million (£590 million) from campaigns associated mainly with the new Windows 8 operating system and the Surface tablet, which is a main beneficiary of the operating system.

Samsung has been accused of rigging reviews by designing its Galaxy S4 hardware to run at higher speeds than normal exclusively in benchmarking apps. According to AnandTech, which performed a number of tests on the Exynos 5 Octa-packing version of the smartphone, the GPU performance jumped significantly when running specific benchmarking tools like Antutu, GLBench 2.5.1 and Quadrant. While the S4's GPU is clocked at 480MHz for regular usage, this rose by 11 per cent to 532MHz under test conditions. Furthermore, Anandtech discovered that Galaxy S4 CPU speeds – in both the Exynos 5 Octa and quad-core Qualcomm Snapdragon versions - were also subject to illegal weighting. As soon as a benchmarking app was opened, the processor's performance suddenly soared to maximum capacity. Samsung has since issued a statement, claiming that it did not intentionally try to rig the benchmark scores: "The maximum GPU frequency is lowered to 480MHz for certain gaming apps that may cause an overload, when they are used for a prolonged period of time in full-screen mode. The maximum GPU frequencies for the Galaxy S4 have been varied to provide optimal user experience for our customers, and were not intended to improve certain benchmark results."

Facebook has hatched plans to sell on-site TV-style advertising for millions of pounds per day as it celebrates its highest share price in over a year. The planet's largest social network, which has 1.15 billion members, is planning to lay siege on the television advertising industry by selling 15-second slots for up to $2.5 million [£1.6 million] per day, two sources familiar with the matter told Bloomberg. Facebook will begin to offer the spots later this year, according to the anonymous sources. Prices, which will reportedly range between $1 million [£685,111] and $2.5 million [£1.6 million], will depend on the size of audience an advertiser wants to reach and users won't see an advert more than three times in a day. Advertisers are only allowed to target users based on age and gender. Even better news for Facebook came as the social network's share price closed at its highest level since their initial public offering (IPO) on May 18 2012. The price rose 4.2 per cent to $35.43 [£23.32] at 16:00 in New York following optimism the company has turned the corner when it comes to generating sales from mobile advertising.

A Samsung Galaxy S4 smartphone allegedly burst into flames and engulfed an entire apartment in Hong Kong, with reports suggesting third-party components were the cause. As first detailed by Xianguo.com, one Mr Du saw his Samsung device heat up before it internally combusted. Du then threw the smartphone under the sofa and within minutes, his apartment resembled the apocalypse. Mr Du and his wife emerged unscathed but insist Samsung is at fault after claims that all of the components he owned and used were Samsung originals. This included the battery, charger and phone itself, although experts are already doubting this is the case and are quoted as saying it's "highly unlikely" the parts were all legitimate. Samsung Hong Kong is investigating the case and chemical analysis of the explosion is being carried out to determine whether Samsung or a third party made the parts that caused the accident.