Introduction

The Gigabyte UD uses the same platform as the P-GM series, but with improvements to iron out all issues. MEIC, the OEM behind these units, didn’t put on a good start in the desktop PSU market, but Gigabyte seems to have faith in the OEM. The UD line consists of three models with 750 W, 850 W, and 1000 W maximum power output. I reviewed the updated flagship model featuring a 600 W PCIe 5.0 connector, so it is time to look at the lower capacity units that are not ATX v3.0 compatible and lack the new PCIe connector, which means I won’t have to run the extra-demanding transient response tests with 120%, 160%, 180%, and 200% of the PSU’s maximum capacity.

Speaking of the new transient response requirements, or power excursions as the ATX specification calls them, I remember having a conversation with Intel about it, and I asked why they didn’t push GPU manufacturers to implement stricter DC-DC circuits on their designs to restrict power spikes instead of having PSU manufacturers factor in transient loads of up 200% on their designs! With the release of the NVIDIA RTX 3090 Ti, power spikes are nowhere close to 200% of the maximum-rated capacity for very short periods of time. Why am I mentioning all of this? Because as I see it, the new GPUs use better power circuits to filter out most power spikes, so these crazy PSU transient response requirements won’t be necessary—the ATX v3.0 requirements will be overkill, leading to higher PSU prices for no reason. Nobody can tell for sure, and we will have to wait until the new GPUs are available to conduct the simple test of taking several PSUs that fail to meet the ATX v3.0 transient response tests and installing them in real systems to figure out if they can support the GPUs and there are no issues.

To measure GPU power spikes more efficiently, I am in the design phase of a special Power Measurements Device (PMD) for high polling rates without using Hall effect sensors but shunts to remove unwanted EMI noise from the equation. If everything goes as planned, which is highly unlikely given the current worldwide situation, the PMD will be ready this summer, and I will put together an article to present it.

Specifications