The smartphone giant expects second-quarter operating profit to decline 4 percent and miss analysts' expectations.
A glut of inventory, Microsoft's offer for free upgrades to Windows 10 and an overall stagnant market combine for a projected decline in sales.
Electronics giant estimates operating profit declined 30 percent year-over-year.
As the tablet market slows, mobile computing is gravitating toward devices that can convert from a tablet to a laptop and back again.
The Japanese company will talk up its latest gadgets during an event in Berlin. The invite hints at a broad array of devices, from smartphones to cameras to TVs.
The Korean electronics giant posts a 74 percent drop in its mobile business operating profits during the September period.
Electronics maker HTC will launch the Vive in "limited quantity" this year and follow that up with a wide launch in the first quarter of 2016.
The company says that it will focus on its games, media, and consumer products divisions and needs to be more "agile" as it looks to improve its financial position.
On the day of the Galaxy Note 5 and Galaxy S6 Edge+ launch, Samsung is attempting to sway iPhone users.
AT&T and T-Mobile will offer cellular-ready versions of the Samsung tablet in early September.