Board Layout

The ASRock X399 Phantom Gaming 6 uses large brushed and black heat sinks with silver accenting over the chipset. The PCB is black with silver and red streaks patterned diagonally on the bottom half. The larger VRM heatsink doubles as a shield over the rear I/O, a smart solution to save space without sacrificing cooling performance.

The back of the ASRock X399 Phantom Gaming 6 is a similar black, but not empty. ASRock has placed a few key controllers on the back of this board, most notably for the 2.5 Gb/s LAN. This is the same as I saw on the Z390 Phantom Gaming 9, which makes sense. Although very attractive overall, the board is less neutral than ASRock's Taichi boards because of the red accenting.


The CPU socket is as open as can be reasonably expected when surrounded by DIMM slots. I would expect most coolers to do alright here, but liquid coolers definitely have an advantage, especially if you plan to use all eight DIMM slots.


There are three M.2 slots on the ASRock X399 Phantom Gaming 9; the first is between the first and second PCIe slots, while the other two sit side by side just below the chipset, between the second and third PCIe x16 slots.

The full-coverage heatsink is implemented in the first top M.2 slot since mounting would be tricky for the other two. This is a little disappointing as I have praised other recent ASRock boards for moving this heat sink down and away from the GPU. The more crowded layout of the X399 board pretty much forces ASRock's hand here, and to be honest, it shouldn't really have any effect on M.2 performance.


There is also an M.2 WiFi slot just under the audio ports on the rear I/O. ASRock included a bracket for the antenna ports should a card not come with a bracket.


The ASRock X399 Phantom Gaming 6 offers three PCI Express 3.0 x16 slots, all encased in steel armor. The board has a total of eight SATA 6 Gb/s ports, and all are angled 90 degrees from the board.


The ASRock X399 Phantom Gaming 6 has a decent rear I/O offering including two LAN ports and an Optical S/PDIF Out port.

• 1x PS/2 keyboard and mouse combo connector
• 8x USB 3.1 Gen1 Type-A ports
• 1x USB 3.1 Gen2 Type-A ports
• 1x USB 3.1 Gen2 Type-C port
• 2x RJ-45 LAN ports
• 1x Optical SPDIF out port
• 5x 3.5 mm audio jacks

Networking on the ASRock X399 Phantom Gaming 6 is handled by a GigaLAN Intel I211AT and the Realtek Dragon RTL8125AG for 2.5 Gigabit LAN.