The be quiet! Pure Power 13 M 1000W and the be quiet! Pure Power 13 M 850W are objectively tied, as both units share five identical specifications. The primary differentiator between these power supplies is their specific capacity and cost positioning. The 1000W model provides an 18% advantage in total wattage, offering more headroom for power-hungry systems, while the 850W model holds a 19% advantage in MSRP, making it the more cost-effective choice for standard builds.

Choose the be quiet! Pure Power 13 M 1000W if your system requires the additional 18% wattage capacity to support high-draw components. Conversely, select the be quiet! Pure Power 13 M 850W if you want to capitalize on the 19% MSRP advantage. Since both units are otherwise identical in their technical specifications, the decision rests entirely on whether your specific hardware configuration necessitates the higher power ceiling or if you prefer the savings offered by the lower-wattage option.