Apple has at long last announced that sales of its new, cylindrical Mac Pro will begin on Thursday, December 19, making good on the promise the company made in late October at its last product event. The workstation starts at $2,999, which will get you a 3.7GHz quad-core Intel Xeon E5-1620 v2, 12GB of 1866MHz ECC DDR3 RAM, a 256GB PCI Express SSD, and two AMD FirePro D300 GPUs with 2GB of GDDR5 RAM apiece. Stepping up to the $3,999 model bumps you up to a 3.5GHz six-core Xeon E5-1650 v2, 16GB of RAM, and two FirePro D500 GPUs with 3GB of GDDR5 RAM apiece.

The new Mac Pro is the first major internal refresh the computer has gotten since 2010 (a very minor spec bump happened in 2012 ), and it's the first redesign of the chassis since the Intel-based Mac Pro came out in 2006. That case was itself a rather minor modification to the Power Mac G5 design, which goes all the way back to June of 2003—the new Mac Pro replaces a design that's effectively a decade old. The old Mac Pro weighed around 40 pounds; the new one starts at just 11.

To make the machine as small as it is, Apple has jettisoned much of the internal expandability that defined the Mac Pro for so long. Gone are the PCI Express expansion slots—the computer can be upgraded to a dual-FirePro D700 configuration when you buy it, but those are the GPUs you're stuck with for the life of the machine. The RAM and the PCI Express-based SSD should be upgradeable by users (up to 64GB of RAM and a 1TB SSD can be added at purchase), but the internal HDD bays of the old machine are absent. And while modern Ivy Bridge-based Xeons can fit up to 12 CPU cores on a single chip, the Mac Pro's step down to a single processor socket will put to rest your dreams of a dual-socket, 24-core monster.

To replace that internal expansion, Apple is relying on the new Mac Pro's six Thunderbolt 2 ports. The new version of Thunderbolt, also used in the latest Retina MacBook Pros, increases the maximum theoretical bandwidth to 20Gbps (or 2.5 gigabytes per second). This should be more than enough provided you're willing to spring for an expensive external storage array. The ports (along with the two GPUs) can also support up to three 4K displays at once, though as of this writing Apple doesn't manufacture its own Retina-class Thunderbolt displays. All models also come with four USB 3.0 ports, two gigabit Ethernet ports, an HDMI port, 1.3Gbps 802.11ac Wi-Fi, and Bluetooth 4.0.

Ars workstation guru Dave Girard will be giving the new Mac Pro a thorough review in the days ahead. In the meantime, you can view all of the different Mac Pro configurations on Apple's Mac Pro page here.