I bought an HP Omen 45L prebuilt after its original GPU was removed. I already have an RTX 3080, which uses two 8-pin PCIe power connectors, but the system's non-modular DPS-1200AB-26 A power supply only has a 12VHPWR GPU cable available. HP lists the PSU as ATX 3.0 and PCIe 5.0/12VHPWR compliant. The original graphics card was an RTX 5090, so it required substantially more power than my RTX 3080. Would it be safe to use a properly rated 12VHPWR-female-to-dual-8-pin PCIe adapter, or is there a meaningful risk of overheating the connector, damaging the cable, or frying the GPU?
3 Answers
The 3080 draws less power than the card this machine was designed to run, so the power budget is likely fine. However, 12VHPWR connectors have had overheating problems when they are not seated completely or when an adapter is poorly made. I would avoid the cheapest cable available and verify that it is specifically intended to convert a PSU-side 12VHPWR connection into two GPU-side 8-pin PCIe connectors.
I would personally replace the PSU rather than add an adapter. Even if the wattage is sufficient, the connector and cable quality matter, and an extra connection introduces another possible failure point. If you do use one, check the cable’s wattage rating and pinout, use both 8-pin plugs, and inspect the connector after the first few hours of gaming for heat, discoloration, or a melted-plastic smell.
Because the original system supported an RTX 5090, the PSU and its 12VHPWR output should have enough capacity for an RTX 3080. A correctly wired, reputable adapter rated for the required wattage will probably work. Make sure the 12VHPWR plug is fully inserted and avoid sharply bending or putting tension on it near the connector.
The original GPU was an RTX 5090, so it should have required considerably more power than my RTX 3080. I’ll make sure the adapter is properly rated and that the connector is fully seated before considering it.