Dell had high hopes for the Alienware Steam Machine after its delayed release last year, but it did not become as popular as its twin, Alienware Alpha, a Windows-based PC gaming console.

The viability of Steam Machines, a family of Linux-based PC gaming consoles with SteamOS, has been questioned, but Dell isn't giving up yet. With better hardware and an expanding list of gaming titles, Dell is hoping that interest in Alienware Steam Machines will grow.

The Steam Machine's rectangular console is based on a concept design from Valve, the world's largest independent game distributor. At the E3 show this week, Dell is announcing Steam Machines with faster graphics processors and chips. The systems will start shipping this week.

A lack of top gaming titles has hurt Steam Machines. The number of titles doesn't match that available for Windows, the focus of most PC game development.

It's a slow process, but as Dell improves the Alienware line, more attention is being paid to gaming in SteamOS and Linux, said Chris Sutphen, senior marketing manager at Alienware.

"We expect the SteamOS catalog to strengthen at the end of year," Sutphen said.

Steam Machines will get a boost from Vulkan, an API (application programming interface) that will improve graphics and gaming on mobile devices and PCs. Vulkan, which was released earlier this year, is already improving gaming on Linux and Steam Machines PCs, much like how DirectX 12 advanced gaming in Windows 10.

Vulcan will also make it easier to port DirectX 12 games to work on Steam Machines. It originally took a long time to port games from DirectX to OpenGL -- Vulkan's predecessor, introduced in 1991 by Silicon Graphics.

"Vulkan will speed up transition for SteamOS to AAA content," Sutphen said. AAA content refers to top-line gaming titles.

Gamers usually want the latest and greatest hardware, and one of Vulkan's strengths is to exploit GPUs to render powerful graphics. Dell is packing the latest chips into its new Alienware Steam Machines with the goal of matching gaming on Windows.

A new Alienware Steam Machine priced at $749 will have the Intel quad-core Core i5 chip based on the Skylake architecture, Nvidia's GTX 960 GPU, 8GB of DDR4 memory, a 500GB hard drive and 802.11ac Wi-Fi.

For more horsepower, a $899 Steam Machine will be loaded with a Skylake-based Intel Core i7 chip, an Nvidia GTX 960 GPU, 8GB DDR4 DRAM, a 1TB hard drive and 802.11ac Wi-Fi.

Both the new Steam Machines will have the Steam Controller and a content bundle. Dell said a version of the Steam Machines with AMD's GPUs could come later this year.

For budget customers, Dell will continue to offer the original Alienware Steam Machine, which started shipping last year for $449.

Dell also introduced faster versions of the Alienware Alpha with Windows, which offers better graphics performance, storage and connectivity. The systems can also run PC applications.

The new Alpha systems run on Intel Skylake processors, and could be configured with AMD's Radeon R9 M470X or Nvidia's GeForce GTX 960. Memory capacities range from 4GB to 16GB of DDR4 DRAM, while storage can be up to 2TB. Prices start at $599.

The new Alphas can also work with the latest GPUs through the Alienware Graphics Amplifier, a $199 external attachment that can bring additional graphics power to GPUs. The amplifier will bring virtual reality capabilities to the Alphas, said Frank Azor, general manager at Dell. The Amplifier will help gamers play games via Nvidia's upcoming Pascal GPUs at a later date.