Expansion, I/O, and audio
As a full ATX motherboard, the Pro Carbon offers builders ample room for storage devices and expansion cards.
The first stop on our tour of the Pro Carbon's expansion options is the primary M.2 slot and its integrated heatsink. This slot takes the place of the usual PCIe x1 slot that tends to be the first on many Z370 boards. In a nifty touch, MSI integrated the retaining screw for the SSD and the retaining screw for the heatsink into one fastener. Most other boards with integrated heatsinks use a traditional standoff for the M.2 drive itself and a separate screw for the heatsink, so I appreciate the convenience of this approach.
The board's two CPU-powered PCIe x16 slots both get a full metal jacket to provide resilience against shearing forces when a builder moves or ships their PC. I'd always remove a hefty graphics card from a system before moving it or trusting it to a shipper, but MSI at least lets those not so inclined to try their luck.
The primary PCIe x16 slot gets 16 lanes of PCIe 3.0 from the CPU with one graphics card installed. Plugging another graphics card in for SLI or Crossfire splits those lanes into two x8 connections running to each metal-jacketed slot.
Chipset-powered PCIe slots occupy the remainder of the Pro Carbon's board space. Each PCIe x1 slot gets a dedicated lane of PCIe 3.0 from the Z370 chipset. The last physical x16 slot on the board enjoys a dedicated x4 connection to the PCH, as well. Given the headache-inducing lane-sharing arrangements that pop up on some Z370 boards, the Pro Carbon's straightforward layout is a breath of fresh air.
The Pro Carbon does perform some lane-sharing, but only in the storage department. In what I expect will be the most common arrangement, plugging an NVMe SSD into the primary M.2 slot on the Pro Carbon leaves all of the board's SATA ports functional. Hallelujah.
SATA ports only start going dark on the Pro Carbon when one starts installing SATA devices in M.2 slots or when both M.2 slots are in use. Put a SATA drive in the first M.2 slot, and SATA port 1 goes dark. Put a second SATA M.2 device in the second M.2 slot, and SATA ports 1 and 5 both go offline. Put an NVMe SSD in the second M.2 slot, and SATA ports 5 and 6 go dark.
While builders will need to be careful about the protocol and position of their M.2 storage devices, the Z370 Pro Carbon will always offer at least four SATA ports to go with its M.2 slots. Storage-hungry builders should take note.
The Pro Carbon's I/O cluster comes well-stocked with a mix of legacy and modern ports. Moving from left to right, the first stop is a PS/2 combo port for mice and keyboards. Two USB 2.0 ports from the Z370 chipset rest under this legacy connector.
A single DisplayPort 1.2 connector capable of running 4K displays at 60 Hz sits in the canyon between the old and the new on the Pro Carbon. To its right, we find a USB 3.1 Gen 2 Type-A port and a Gen 2 Type-C port, both powered by ASMedia's latest-and-greatest ASM3142 controller. MSI backs up this high-speed chip with two PCIe 3.0 lanes from the Z370 chipset.
The next connector block in the Pro Carbon's lineup houses two USB 3.0 ports from the Z370 chipset. These sit above an HDMI 1.4 connector capable of driving displays with resolutions up to 4096x2160 at 30 Hz. The next block over houses the RJ-45 connector for the board's Intel I219-V Gigabit Ethernet controller and two more USB 3.0 ports from the Z370 chipset.
Like virtually every mainstream motherboard we see these days, MSI taps Realtek's ALC1220 codec (under the Audio Boost 4 banner) for analog audio duties. MSI does include some Nichicon caps in the Pro Carbon's audio chain, but headphone amp and DAC duties are all handled by the ALC1220's built-in circuitry. The ALC1220 is a fine codec, but it's presented in about as unadulterated a form as it can be on the Pro Carbon.
As a result, the Pro Carbon's sound is serviceable, but not a standout among the other ALC1220-equipped boards that I've tried. The codec's default voicing seems light on bass with a typically narrow stereo image. My preferred EQ curve (more bass, more highs, and less mids) livens up the Pro Carbon's sound signature, as it does with other ALC1220 boards. That performance is just fine for basic audio output duties, but it's not going to transport anybody to sonic nirvana in the same way that fancier onboard setups might.
MSI also offers Pro Carbon owners access to the Nahimic sonic sweetener software, for lack of a better term. Nahimic offers a wide range of potential audio massaging, but it takes forever to load on the Pro Carbon for some reason. Its enhancements also didn't seem to do much that an EQ curve wouldn't in its own right. I also wasn't that impressed with the app's simulated surround sound, whose output seemed more like a strong reverb than anything. Nahimic might be useful for its microphone noise suppression, but I'm not sure that feature is worth dealing with the app's pokey performance and otherwise not-that-impressive audio enhancements. Give it a shot, but don't expect miracles.