Modularity is the word of the day as far as Apple’s newly announced and redesigned Mac Pro is concerned. The computer features a return to the older “cheese-grater” look, but redesigned and with a strong eye toward flexibility and expansion.

The question for owners of the most recent desktop Mac powerhouse, the iMac Pro, will be: Should I abandon my current system for the new Mac Pro, which will start at $5,999? (The iMac Pro starts at $4,999, but includes a 27-inch 5K display.) We took a look at the specs of the current iMac Pro, which launched back in December of 2017, and what was announced today for the new Mac Pro, which will ship this fall.

The question for owners of the iMac Pro will be: Should I abandon it for this new Mac Pro?

But before we go into the specs, one important difference: the new Mac Pro will be user-configurable and the iMac Pro is not. This alone can make a huge difference, especially for creators or businesses that may want to upgrade their systems in the future.

Processors

Both the iMac Pro and the new Mac Pro 2019 run on the Intel Xeon W processor, which was first introduced in August 2017 and has been updated since. The iMac starts with an eight-core, 3.2GHz processor and goes up to an 18-core, 2.3GHz processor with 19MB of cache. The Mac Pro starts with a more powerful 3.5GHz, eight-core processor with 24.5MB of cache and zooms up to an impressive 28-core, 2.5GHz processor with 66.5MB cache.

Memory

The iMac Pro supports 32GB / 64GB / 128GB / 256GB of DDR4 ECC memory. The new Mac Pro will handle from 32GB to 1.5TB of DDR4 ECC memory and will be completely user-configurable.

Graphics

The iMac Pro comes with an AMD Radeon Pro Vega 56 graphics processor with 8GB of HBM2 memory; you can also opt for the higher-level Vega 64 and 64x processors, both with 16GB of memory.

The Mac Pro will let you configure two of Apple’s new MPX Modules with up to four GPUs. You will have the choice of the AMD Radeon Pro 580X (8GB of GDDR5 memory), the AMD Radeon Pro Vega II (32GB of HBM2 memory) or the AMD Radeon Pro Vega II Duo, which comes with two Vega II GPUs and a total of 64GB of HBM2 memory.

Expansion and ports

Here’s where the advantage of the Mac Pro is especially obvious. It will come with eight PCI Express card expansion slots: two MPX bays (which can also be used as four PCI Express slots), three full-length PCI Express slots, and a half-length PCI Express slot. This last slot will ship holding an I/O card with two USB 3 ports, two Thunderbolt 3 ports, and a 3.5mm audio jack; the system will also include two Thunderbolt 3 ports on top by the power button and two 10Gb Ethernet ports on the back. The iMac Pro offers an Ethernet port, an SDXC card slot with support for UHS‑II, four USB 3 ports, and four Thunderbolt 3 (USB-C) ports — none of which can be changed or upgraded.

Our conclusion? Well, obviously we can’t make any judgements about the worth of Apple’s new Mac Pro until we have one in hand and can give it a thorough test. But judging from the initial specs, this could be a really impressive machine for creators and others who need speed, flexibility, and the ability to upgrade when they want to.