Member Avatar for RemingtonSteele

I was just trying to get a recomendation on what size power supply I needed for my system.

AMD Phenom XII 940 3.0 GHz /w. factory heat sink
GIGABYTE GA-MA790GP-UD4H AM3/AM2+/AM2 AMD 790GX HDMI ATX
SAPPHIRE 100259-1GL Radeon HD 4870 1GB
2 Sticks of DDR2 1066 2GB RAM
Western Digital Caviar Black 1Tb HD
LG Blu-Ray/HD dvd player
2 case fans

I paid $40 for a 475 watt and I just got my computer put together and was playing Crysis when the power supply just gave up the ghost. I'm planning to order a 700 or 800 watt PSU; just want to get some feedback on it.

Thanks!
Jake

  • 3 Contributors
  • 3 Replies
  • 227 Views
  • 1 Day Discussion Span
  • Latest Post Latest Post by RemingtonSteele

Dani AI

Generated

Short answer: a good-quality 500–650 W PSU is the sweet spot for that Phenom II / single HD4870 build; 700–800 W is only necessary if adding another card or doing heavy overclocking. The HD4870 is a power-hungry card (about 150 W and it needs two 6‑pin PCIe connectors) and the Phenom II X4 940 has a ~125 W TDP, so a reputable 550–650 W unit gives safe headroom for drives, fans and transient spikes. (techpowerup.com)

Why the 475 W likely died: many very cheap PSUs cannot sustain their rated continuous +12 V output, skimp on protections and use low‑quality components. is right to suggest extra headroom, but is also right that a $40 PSU is a false economy — quality and rail capability matter more than a high printed wattage. Look for an 80 PLUS Bronze (or better) unit from a reputable maker and check real reviews and warranty length. (pcworld.com)

Actionable steps: replace the dead unit rather than reuse it; avoid molex‑to‑6‑pin adapters if possible and confirm the PSU has two native PCIe power cables. Use an online calculator to estimate system draw and pick a unit with ~15–25% headroom (OuterVision is a good calculator). If planning CrossFire/SLI or big upgrades, step up to 700–800 W; otherwise a well-reviewed 550–650 W 80 PLUS Bronze/Gold supply from a known brand (Seasonic/Corsair/EVGA/etc.) will be quieter, more reliable, and long‑lived. (outervision.site)

Practical checklist: confirm required PCIe plugs, check the new PSU’s +12 V rail amperage on the spec sheet, prefer modular or semi‑modular for cable management, and keep the warranty receipt.

Recommended Answers

All 3 Replies

Member Avatar for Salem

Double what you had.

The more capable it is, the longer it will last and the quieter it will be while it is running.

Member Avatar for caperjack

pay more than 40$ for one !

Member Avatar for RemingtonSteele

Thanks for the Feedback!

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.