The DeepCool PX850G and the Thermaltake Toughpower GF A3 850W are objectively tied, as both units share five identical specifications. When comparing the primary advantages, the DeepCool PX850G holds an 8% lead in MSRP, making it the more cost-effective option based on the provided data. Conversely, the Thermaltake Toughpower GF A3 850W offers a 3% advantage regarding its ATX version, providing a slight edge in standard compatibility for modern system builds.

Choose the DeepCool PX850G if your primary goal is to minimize your initial expenditure, as its superior MSRP provides the most significant financial benefit. If your priority is ensuring the latest ATX version for your power supply configuration, the Thermaltake Toughpower GF A3 850W is the better selection. Because both units perform identically across the majority of measured specifications, your final decision should rest solely on these specific advantages in pricing and versioning.