ASRock Z790 PG-ITX/TB4 Review: Cheapest Mini-ITX Option With TB4/USB4

The ASRock Z790 PG-ITX/TB4 is a Mini-ITX motherboard that’s built on the latest enthusiast Intel chipset, supporting 12th and 13th generation processors. The tiny board is the least expensive of Z790-based ITX options, at $334.99 at the time of this writing. For the money, you get a PCIe 5.0 slot, three M.2 sockets (all PCIe 4.0), flagship-class audio (including a DAC), Killer-based networking, and robust power delivery. It may not look the best visually compared to the others (in our opinion), but the hardware and feature list is impressive for the price.

ASRock’s Z790 lineup hasn’t changed drastically since the chipset’s release, but with a couple recent additions, it now consists of 15 different SKUs. You’ll find all the standard sizes and wide-ranging prices, with familiar names like the Taichi, Steel Legend, Riptide, Pro, and the funky purple LiveMixer SKU. Prices range from $499.99 (Taichi Carrara) to the ASRock Z790M PG Lightning/D4 at $169.99 ($179.99 at launch). The existing lineup has plenty of options, but we’re still waiting for a water-cooled Aqua.

Performance-wise, the PG-ITX/TB4 was average in most tests. None were exceedingly slow, and none led the pack. It did the best in gaming, which was above average across the board. But performance was slightly below average across the Procyon Office tests. As usual, during heavy sustained loads, there’s thermal throttling in some tests with out-of-the-box settings. Out of the box, we set our cooler type in the BIOS to a 360mm AIO, which sets PL1/PL2 equal, so the processor can constantly pull the full boost wattage until it thermally throttles. To get the most out of these high-powered processors, you’ll need to use an offset voltage so the clock speeds can be sustained.

Below, we’ll dig into the details of the board and see whether it deserves a spot on our Best Motherboards list. Before we get into our testing and board specifics, though, we’ll start by listing the specifications from ASRock’s website. 

Specifications: ASRock Z790 PG-ITX/TB4

Inside the Box of the ASRock Z790 PG-ITX/TB4

Inside the retail packaging, below the motherboard, ASRock includes a few accessories to get you started. Along with the motherboard, you get two SATA cables, a Wi-Fi antenna, two thermal pads, and screws for M.2(3) sockets, along with a manual. There isn’t much here, but it’s enough to get you going.

Design of the PG-ITX/TB4

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Our little motherboard sits on a 10-layer matte black PCB. The only design elements come from the actively cooled, heatpipe-connected VRM heatsinks and M.2 heatsinks. They sport a matte, brushed aluminum finish with red and black highlights and Phantom Gaming (PG) branding. If you’re interested in RGB lighting in your chassis, you’ll have to add your own to the onboard headers, as the board does not include any natively. In short, this is a decent-looking ITX motherboard, but some may prefer the competition’s appearance.

Starting in the left corner, we see the required 8-pin EPS connector just above the heatpipe connecting the two VRM heatsinks. The left VRM bank has three slots cut out at the top to help get fresh air over the tiny fan hidden below. The fan makes noise when under heavy loads by default, but you can adjust the BIOS to mitigate that potential concern.

Across the top are four headers, one RGB, and three 4-pin fan headers. The RGB header in this location is 3-pin/ARGB. The other, on the right side of the board, is 4-pin/RGB. Control over the attached devices is handled through ASRock’s Polychrome Sync application. All three fan headers are wedged between the DRAM slots and the ARGB header up top, which helps with wire management. All headers support PWM- and DC-controlled devices. CPU_FAN1 and CHA_FAN1 power up to 1A/12W, while the CPU_FAN2/WP outputs up to 2A/24W. That’s not a lot of power to go around on many headers, but it’s an ITX board typically housed in a smaller chassis, so you should require an abundance of fans.

ASRock uses two reinforced DRAM slots, with its sole locking mechanism on top. The specifications state our board supports up to 96GB of DDR5 RAM at speeds up to DDR5-7000, which is plenty for most people, although it’s technically the ‘slowest’ maximum supported RAM speed among the Z790 ITX boards we’ve seen. So if you plan on pushing the RAM (past 7000 MHz), you’ll want to look elsewhere.

Moving down the right edge, we run into the POST status checker. Four tiny LEDs (VGA, DRAM, CPU, Boot) light up during POST, and if there’s a problem in one of those generic areas, the LED of the offending part remains lit, giving users a general idea of where the problem lies. Next are the 24-pin ATX connector to power the board, the 4-pin RGB header, and the system panel header. Continuing down, we find a 19-pin USB 3.2 Gen 1 (5 Gbps) header, three SATA ports (supporting RAID0/1/5), and finally, a front panel USB 3.2 Gen 2x2 (20 Gbps) header.

Power delivery on the Mini-ITX offering consists of 12 total phases, with 10 dedicated to Vcore. Power comes from the 8-pin EPS connector onto a Renesas RAA229131 20-phase PWM controller. From there, it heads to the 10x 105A Renesas RAA22010540 SPS MOSFETs. The 1050A available for the processor supports the flagship-class Intel i9-13900K, even when overclocked. Your cooling will get in the way before the VRMs do.

We’ll continue our counterclockwise journey at the bottom of the board. Here we run into the only PCIe slot,  a full-length PCIe 5.0 x16 slot. Above that, under the flat heatsink, is the first of three M.2 sockets (you’ll find the other two on the back of the board). Each socket runs at PCIe 4.0 x4 (64 Gbps) speeds and supports up to 80mm modules. One of the sockets, M2_2, supports SATA-based devices in addition to PCIe. There’s no lane/bandwidth sharing, and you can run all storage concurrently without penalty.

To the left of the M.2 socket, above the PCIe slot, is a USB 2.0 header and the front panel audio header. Finally, we can see the Realtek ALC4082 codec in the corner and a couple of dedicated audio capacitors. This high-end codec should satisfy most listeners.

The rear IO plate on the Z790 PG-ITX/TB4 comes preinstalled on the motherboard. It has a black and gray background and the PG branding in the corner. The ports are on one side or the other of the available space to make room for ventilation for the VRM fan. DisplayPort and HDMI ports for integrated video are on the left, along with six USB 3.2 Gen 2 (10 Gbps) ports (blue). The real draw for this board is the pair of Thunderbolt4/USB4 40 Gbps Type-C ports. If you want ultra-fast external connectivity, this board has you covered. But only six Type-A ports back here means some users will feel limited. Above those (also in blue) is the Killer X3100 2.5 GbE port, while to the right of the ventilation are the Wi-Fi 6E antenna connections and 2-plug plus SPDIF audio stack.

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