ASRock Z390 Phantom Gaming X Motherboard Review

We Examine ASRock’s Top Z390 Option

At the top of ASRock’s Z390 lineup sits the Phantom Gaming X, a deluxe ATX option for Intel’s desktop processors loaded with features and boasting robust power delivery and build quality.

Among the highlight of the Phantom Gaming X are its 14-phase power delivery with 60A power chokes, extra large aluminum heatsinks to help keep temps down, network support that includes Intel Wi-Fi 6 and dual Intel NICs, and (of course) plenty of addressable RGB support.

Along with its impressive list specifications comes a $319.99 price tag as of this publication, placing the Z390 Phantom Gaming X in an upper tier of Z390 boards on the market – though still far below the $500-$600+ price level of options such as the ASUS ROG MAXIMUS XI FORMULA, EVGA Z390 DARK, or MSI MEG Z390 GODLIKE.

We have used this motherboard extensively for in-house Intel CPU testing, including for our coverage of the power-hungry Intel Core i9-9900KS, and today offer this more comprehensive look at the board we’ve had working behind the scenes over the past few months.

Z390 Phantom Gaming X Design

The Z390 PGX is a standard ATX form-factor motherboard at 12 x 9.6 inches, and features a black high-density glass fabric PCB design which ASRock says “reduces the gaps between the PCB layers to protect the motherboard against electrical shorts caused by humidity”.

The board uses ASRock’s XXL Aluminum Alloy Heatsink solution, with a heat pipe connecting the large 90-degree aluminum heatsink assembly for the MOSFETs, and a single aluminum plate for the chipset and NVMe SSDs.

There is a lot going on with motherboard I/O with the Z390 PGX, beginning with the shield itself. This is integrated as with a number of high-end boards we’ve looked at recently, but ASRock stresses that their implementation is flexible – literally.

This I/O shield can be moved slightly in all directions to make installing it in a case easier. This is a little thing, but if you have installed a motherboard with a pre-attached shield like this you will appreciate ASRock’s approach here.

As to the I/O itself, it’s an impressive array. There are a total of eight USB ports ranging from USB 3.0 to 3.2 (including a Type-C), triple RJ45 LAN (more on the integrated NICs later), DisplayPort and HDMI output, multi-channel analog audio output and SPDIF digital output, Wi-Fi antenna connections, and even a keyboard/mouse combo PS/2 port.

Z390 Phantom Gaming X Features

While an extensive overview of the motherboard can be found from ASRock here, they also provide this condensed list for Z390 Phantom Gaming X:

• Supports 9th and 8th Gen Intel Core processors (Socket 1151)
• Intel 2T2R Dual Band Wi-Fi 6 (802.11ax) WiFi (2.4/5GHz)
• Supports up to 2.4Gbps wireless network and BT v5.0
• Phantom Gaming 2.5 Gigabit LAN, Dual Intel Gigabit LAN
• Digital PWM, 14 Power Phase design
• Supports DDR4 4266+(OC) MHz
• 3 PCIe 3.0 x16, 2 PCIe 3.0 x1
• NVIDIA Quad SLI, AMD 3-Way CrossFireX
• Graphics Output Options: HDMI, DisplayPort
• 7.1 CH HD Audio (Realtek ALC1220 Audio Codec)
• Supports Creative Sound Blaster Cinema 5
• 8 SATA3, 3 Ultra M.2 (PCIe Gen3 x4 & SATA3)
• 5 USB 3.2 Gen2 (1 Front Type-C, 1 Rear Type-C, 3 Rear Type-A)
• 8 USB 3.2 Gen1 (4 Front, 4 Rear)
• ASRock Polychrome SYNC
• Hyper BCLK Engine II

Focus on Power Delivery

A key aspect of the Z390 PGX is its CPU power design, which comprised of 14 phases, each with up to 50A continuous current. This is accomplished by implementing 14 Vishay SiC634 power ICs, with each able to deliver “in excess of 50 A continuous current, 55 A at 10 ms peak current” according to the product sheet (PDF).

A 7-phase PWM controller is implemented here, with the Renesas Intersil ISL69138 (product sheet, PDF) designed for high-performance, high-end desktop and OC applications. As this controller is 7-phases max, a total of 7 doublers (Intersil ISL6617A, PDF) are implemented.

For a closer look at power delivery I recommend KitGuru’s excellent Z390 PGX review, which goes in-depth into this area with plenty of macro photography.

PCI Express switching is employed with this design (“PLX” chips), with these NXP PCIe 3.0 switches (NXP CBTL04083A, PDF) routing available CPU lanes to their respective PCIe slots based on what is currently installed. As this i9-9900KS is an Intel desktop processor, just 16 PCIe lanes are available from the CPU.

From the specs we see a standard division for the board’s three x16 slots:

PCIE1/PCIE3/PCIE5: single at x16 (PCIE1); dual at x8 (PCIE1) / x8 (PCIE3); triple at x8 (PCIE1) / x4 (PCIE3) / x4 (PCIE5)

The addition of these PCIe switches seems to be rare for a Z390 motherboard, with very few options available.

Networking in Abundance

With four integrated solutions – wired and wireless – the Z390 Phantom Gaming X is certainly no slouch in the networking department. It offers the latest in wireless network support with Intel Wi-Fi 6 (802.11ax) onboard. This 2T2R dual-band solution offers max speeds of up to 2.4Gbps.

“Welcome to the new Wi-Fi standard! ASRock’s motherboard equipped with next generation Intel Wi-Fi 6 802.11ax adapter. The speed will be working up to 2.4Gbps and it will also natively operate with both 2.4Ghz and 5Ghz simultaneously. Significant improvement in bi-directional MU-MIMO support is another attractive feature as well.”

Wired networking support includes no fewer than three onboard NICs, with dual Intel Gigabit (Intel I219V + Intel I211AT) plus a Phantom Gaming 2.5 Gigabit (Realtek Dragon RTL8125AG) LAN.

“The intelligent Phantom Gaming 2.5Gb/s LAN platform is built for maximum networking performance for the demanding requirements of home networking, content creators, online gamers and high-quality streaming media. Boost networking performance up to 2.5X the bandwidth compared to the standard gigabit Ethernet, you’ll enjoy the faster and uncompromised connectivity experience for gaming, file transfers and backups.”

One area of note, however, is the lack of a 10 Gigabit NIC, which the lower-cost Taichi Ultimate brings to the table (more on the value proposition between these two ASRock boards later in the review).

UEFI

ASRock’s UEFI setup defaults to an intuitive “EZ” mode, which provides a simplified interface for basic functions.

The EZ Mode functionality includes setting memory XMP profiles, CPU fan profile presets, and a boot priority selection (with a nice drag-and-drop style interface). Basic system health stats (fan status, CPU temp, Motherboard temp, CPU voltage) are also displayed here.

Moving on to the Advanced Mode (toggled using F6) we are presented with the usual assortment of granular control options, with a total of 8 pages; Main, OC Tweaker, Advanced, Tool, H/W Monitor, Security, Boot, and Exit (which includes boot override).

The amount of control from the various sub-menus is quite extensive, and I won’t attempt to create a UEFI guide here. Pages 70 – 117 of ASRock’s user manual (PDF) provide a description of each setting, and is a good resource as you explore Advanced Mode.

One standout aspect of ASRock motherboards that we have noted is the frequency of BIOS updates, on both the AMD and Intel side. We tested the Z390 Phantom Gaming X using the latest version of the BIOS, 1.20.

Overall the UEFI interface is solid, with the only aspect that I’d like to see changed being the manual input of percentage/temp values for fan curves. This older method still works just fine with the ASRock setup, but other vendor’s UEFI setups offer simple point-and-click fan curve adjustments.

Performance

For a quick CPU performance comparison with another available Z390 motherboard, a GIGABYTE Z390 AORUS PRO from our GPU test bed was benchmarked with the same Intel Core i9-9900KS CPU. Both boards had their latest BIOS updates applied before benchmarking, with version 1.20 for the Z390 PGX and F12d for the Z390 AORUS PRO.

Cinebench R20

Results with Cinebench were averaged from six runs, rather than our usual three, due to the typical score variance (particularly for multi-core).

The ASRock Z390 Phantom Gaming X consistently out-performed the AORUS PRO here, but not by a huge margin. It turns out that finding stock performance variance between two boards using the same chipset and CPU is something of an exercise in futility, but we push on.

Blender

Using Blender 2.8.1 and both the BMW and Classroom test files, here are the average render times from three runs:

Here the AORUS PRO had a slight edge over the ASRock Z390 Phantom Gaming X, but less than once second separated the average render times with both tests.

7-Zip Benchmark

The built-in 7-Zip benchmark (version 19.00, 64-bit) averages the results from four consecutive runs, measuring both compression and decompression in MIPS.

The ASRock PGX leads slightly here with compression trails, a lead offset by its slight disadvantage in decompression. The combined numbers – 152293 MIPS for the ASRock PGX vs. 152269 for the AORUS PRO – are very close.

x264 Benchmark

This benchmark, run in 64-bit mode, encodes a high quality video file at 1080p using the x264 encoder. The results from the four consecutive 2-pass runs are averaged on the chart below.

The ASRock PGX leads again here, but the slight advantage in the quick first pass doesn’t translate into any significant time savings overall with the long second pass a virtual tie.

Photoshop and Premiere Pro

We tested performance from these two Adobe applications using the handy PugetBench benchmark for Photoshop and Premiere Pro. Our Adobe CC install of Photoshop was version 21.1.0, with version 14.0.3 of Premiere Pro.

Immediately apparent is the impact of higher GPU performance from the AORUS PRO board in these tests, as PugetBench is using CUDA when available.

The ASRock PGX takes a back seat to the GIGABYTE board in both Adobe CC tests, and it will be interesting to see if this apparent GPU performance advantage translated into higher gaming performance.

Synthetic GPU Testing

Chasing variance in GPU performance between two motherboards identical chipset, CPU, memory, and (of course) GPU, can be even less fruitful than CPU benchmarking. Rather than going through “real-world” game testing we quickly tested performance using a couple of synthetic benchmarks, with the results once again averaged from three separate runs of each.

First up was Unigine Superposition, run using DirectX at both the 1080p High and 1080p Extreme presets.

The results from Unigine Superposition at the lower 1080p High preset indicate a CPU-bound condition, though moving up to 1080p Extreme only produced a variance of about 2 FPS, though the advantage was consistent across all runs.

The CUDA rendering advantage we noted from the Adobe CC tests did indeed seem to translate into higher 3D performance numbers in some cases, though the first result using the Basemark GPU test shows virtually zero difference. This benchmark is not particularly challenging even at its “High” preset, which is a 3840×2160 test. DX12 mode was used.

Here we see another minuscule difference with the same RTX 2080 FE card, though I was surprised by the huge impact running the benchmark at the “Medium” preset had on the ASRock board. Again, same CPU, GPU, memory, driver and OS versions, etc., but the Z390 PGX suffered from severe frametime issues that appeared to be bandwidth-related.

I will caution that this test, which should really never be run at “medium” on a system like this, has zero real-world implications. However, it is interesting to see that, when pushed to the ~1000 FPS range with a low-complexity test like this, the minor GPU performance delta we observed was exacerbated to the extreme.

I theorize that the design of the Phantom Gaming X, which implements switching chips for the CPU PCIe lanes, suffers a slight hit to latency that can be demonstrated with unrealistic cases such as the above Basemark test. (I did revisit this particular test to verify before publishing, with the same result.)

Final Thoughts

The Z390 Phantom Gaming X is the flagship product of ASRock’s Z390 lineup, and provides an impressive mix of features to help it stand out from the vast selection of Z390 options on the market. Pricing places it into a more “premium” territory for gaming motherboards, though it is nowhere near the most expensive option available.

While evaluating this motherboard it is interesting to note that at $319.99 the Phantom Gaming X is positioned above the Taichi Ultimate ($279.99), a board that offers – among other things – AQUANTIA 10 Gigabit LAN (the Phantom Gaming X offers 2.5 Gigabit, and both also offer dual Intel Gigabit LAN). But wired networking is not the only thing separating these boards. The Phantom Gaming X features a more robust power delivery with 14 phases, while the Taichi Ultimate uses a 12-phase design.

In the ‘unique feature’ department vs. the Taichi Ultimate the Phantom Gaming X also offers Ultra USB Power, in which 5V power is converted from the +12V rail to prevent voltage drop, and ASRock’s POST Status Checker (PSC), which is a series of lights that indicate which component (CPU, memory, graphics, or storage) are malfunctioning if you’re having boot issues.

In short, the Z390 Taichi Ultimate might be a better option if you prioritize include getting the fastest available wired networking standard, and the Phantom Gaming X might be the better option if you prioritize power delivery (with useful extras such as the POST Status Checker to help troubleshoot issues when overclocking).

While performance was explored to some extent this review was by no means up to the standard set by our own Morry Teitelman. And speaking of Morry, I will briefly mention CMOS battery placement here – which is not accessible without removing the cover on the lower half of the board. Individual M.2 heatsinks, rather than a single panel (which also acts as the chipset heatsink), would be preferred here.

I have been impressed by the reliability of the ASRock Z390 Phantom Gaming X over the past few months, with only one issue – with memory not on the QVL – eventually solved with manual overclocking. This was another example of how a QVL (Qualified Vendor List), while not exciting reading, can be a vital resource when looking for memory that is guaranteed to work at rated speed/timings (Z390 PGX QVL is linked here).

The presence of PLX-type PCIe switching chips is rare for a Z390 board, more common on X299 motherboards (such as ASRock’s X299 OC Formula, for example). PCI Express bandwidth is at a premium with Intel’s 16-lane desktop CPUs, and it’s an interesting addition here – and one that helps justify the price tag given the additional cost to implement such switching.

We didn’t get into the overclocking potential with this motherboard, which is certainly a big part of its design. The Core i9-9900KS CPU was selected as a pre-overclocked option that can put a strain on a motherboard’s power delivery with an all-core 5.0 GHz frequency, and since that special-edition processor’s launch we have run it in this Z390 PGX board without any performance droop or instability.

GPU performance was slightly behind the tested Z390 AORUS PRO board with the synthetic benchmarks run, but not to any significant degree outside of unrealistic testing scenarios. It is interesting that the CUDA-accelerated Adobe CC tests also favored the AORUS board, while CPU benchmarks favored this ASRock board overall. Only a single-GPU scenario was benchmarked, however.

Bottom line, ASRock’s Z390 Phantom Gaming X is a solid ATX option with an impressive set of features, overbuilt power delivery, and excellent CPU performance. It also offers networking above and beyond most motherboards with dual Intel Gigabit, 2.5 Gigabit, and Intel Wi-Fi 6 all onboard. However it faces stiff competition from ASRock’s own Z390 Taichi Ultimate, which costs about $40 less and offers many of the same features.