Benchmark Results and Final Analysis
We disable any motherboard-specified CPU overclocks for our basic performance tests, and disable XMP since some boards would formerly re-enable those CPU overclocks when XMP was applied. All CPU-based power-saving features are enabled to achieve the best idle power readings throughout these tests.
Both ASRock boards showed reduced graphics scores in 3DMark Firestrike, and the Z390 Phantom Gaming 7 performed poorly in PCMark Creative. We’d expect the performance deficit to show up in Compubench were this simply a matter of graphics performance, but the Z390 Phantom Gaming 7 leads the longest of those tests.
Proving that the Z390 Phantom Gaming 7 doesn’t suffer a graphics tests, it matches competing boards almost perfectly at the higher-quality settings of all four games. A small win at our lower Ashes setting is offset by a small loss at the lower setting of F1 2015.
The Z390 Phantom Gaming 7’s most-serious performance deficits are in applications tested through PCMark. We considered that the problem might be within our installation, reinstalled our test image, and tried again, only be disappointed a second time.
Power, Heat & Efficiency
The Z390 Phantom Gaming 7’s power consumption is on par with comparable boards in the sub-$200 Z390 class.
Those moderate power numbers weren’t exactly helpful to the voltage regulator however: Probing the entire voltage regulator for hot spots, we found some scorching chokes behind the CPU socket, that were over 20 degrees hotter than the hottest spot of the Z390 Gaming SLI. The Z390 Phantom Gaming 9 and Z390 Gaming Pro Carbon's voltage regulator temperatures were checked with a thermistor at the same relative location, but we removed the data since that method is less able to pinpoint such anomalies.
The actual reading of the Z390 Phantom Gaming 7’s hottest choke was 126 degrees C, and it was surrounded by a few other chokes that were only a few degrees cooler: We had to reduce the room temperature to 18 degrees just to keep the board running long enough to get that measurement. Thermal protection for MOSFETs eventually kicked in as these chokes heated surrounding components, but that process took long enough that it occurred after the choke temperature had appeared to quit climbing. Our default configuration relies only on the draft of our liquid cooling systems fan to cool the voltage regulator however, and simply putting more airflow (an extra fan) closer to the Z390 Phantom Gaming 7’s voltage regulator solves the issue.
Percent-based scoring in today’s review uses the average of all seventeen Z390 boards we’ve reviewed. The Z390 Phantom Gaming 7’s 1.7% below-average performance combines with is 2% above-average power consumption to produce a 3.7% below-average efficiency rating.
We’ve added a fan over the voltage regulator of every Z390 board during our overclocking analysis, as overheated voltage regulators have been a problem since the Core i9-9900K’s introduction. That simple solution has resolved the thermal issue of even the hottest boards, yet it didn’t resolve the Z390 Phantom Gaming 7’s lower-than-average overclock. We know that nobody’s willing to completely ignore the value of a board’s features if it comes up a mere 102 MHz short of a top rating, but a loss is still a loss.
On the other hand, the Z390 Phantom Gaming 7 did a solid job of pushing our DDR4-2933 test samples to either 3733 (2-DIMM) or 3800 (4-DIMM) data rates, and even edged out other sub-$200 boards in overclocked memory bandwidth.
Value seekers are always discussing “bang for the buck,” so we always include a performance-per-dollar chart that serves as little more than entertainment when onboard features are what buyers are really paying for. The Z390 Phantom Gaming 7 and its Phantom Gaming 9 sibling score lowest here, because the 2.5GbE controller adds around $30 to both prices.
Having said that, if we wanted a 2.5GbE controller onboard we’d just pony up the extra cash for the Z390 Phantom Gaming 9. It’s a far better board overall, with better features such as an integrated Wi-Fi controller and true 10Gb/s USB 3.1 Gen2 front-panel header, and none of the heat alarms noticed in the Gaming 7. We’d call that $25 well spent.
If the $25 difference caused us to forgo 2.5GbE, we’d jump straight down to Gigabyte’s Z390 Gaming SLI for its better overclocks and lower temps, as well as its lack of PCIe pathway sharing.
Image Credits: Tom's Hardware
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