Apple has updated its iMac line with up to 8-core Intel 9th-generation processors for the first time and Vega graphics options, delivering increases in both compute and graphics performance.

The 21.5-inch iMac ($1,299) now features 8th-generation quad-core, 8GB of memory, a 1TB hard drive, and a Retina 4K P3 display.

The new $1,499 iMac also has an eighth-generation Intel processor, but this model supports 6-core processing, a first for the 21.5-inch iMac. This iMac also includes 8GB of memory, a 1TB Fusion Drive, and a Retina 4K P3 display.

A new option for the 21.5-inch iMac is the ability to upgrade the graphics card. Apple is offering a Radeon Pro Vega 20 option, which the company says is 80 percent faster than the previous graphics card.

While the standard memory configuration remains unchanged at 8GB, Apple is now using faster RAM clocked at 2666MHz, up from 2400MHz. Also, the 21.5-inch iMac can now handle 32GB of memory, up from the previous limit of 16GB.

The 21.5-inch iMac comes with four USB 3 ports, two Thunderbolt 3/USB-C ports, a gigabit ethernet connector, a SDXC card slot, and a headphone jack.

For the 27-inch iMac, Apple has available a CPU upgrade to a ninth-generation 8-core Intel Core processor, as well as a graphics upgrade to the Radeon Pro Vega 48.

All standard configurations of the 27-inch Mac include 8GB of 2666MHz RAM (user-accessible), a 1TB Fusion Drive, and a Retina 5K P3 display. The rear panels sports four USB 3 ports, two Thunderbolt 3/USB-C ports, a headphone jack, an SDXC card slot, and a gigabit ethernet connector.

The iMac's Retina display supports up to 14.7 million pixels, 1 billion colors, 500 nits of brightness, P3 wide color gamut and an wide viewing angle. It has an aluminum and glass enclosure, a 5 millimeter-thin profile, keyboard and a mouse.

All new Macs come with macOS Mojave, the latest version of Apple's desktop operating system. In macOS Mojave, Dark Mode transforms the desktop with a new look, Stacks organizes messy desktops by automatically stacking files into neat groups and FaceTime supports group calling. macOS Mojave also brings iOS apps, including News, Stocks, Voice Memos and Home to the Mac and features a redesigned Mac App Store.

The new 21.5-inch iMac with Retina 4K display starts at $1,299 (US) and the new 27-inch iMac with Retina 5K display starts at $1,799 (US). Both are available to order starting today from apple.com and the Apple Store app, and in Apple Stores and Apple Authorized Resellers next week. The non-Retina display iMac configuration continues to be available for $1,099 (US).

Last year, Apple introduced a revamped MacBook Air and Mac mini. It’s planning to launch a new Mac Pro, Apple’s highest-end desktop without a built-in screen, as early as June.

The Mac hasn’t been Apple’s most important product for decades. But the category is a steady seller, generating about $25 billion in annual revenues for Apple in the past half-decade. Still, the company had only 7 percent of the global market in PC shipments during the fourth quarter, according to Gartner Inc.