When selecting GPS chips, you must prioritize TTFF (Time to First Fix), which indicates how quickly the chip determines its position. Look for chips supporting Multi-GNSS (GPS, GLONASS, Galileo, BeiDou) to ensure global coverage and redundancy. Additionally, evaluate the Sensitivity (measured in dBm); high-sensitivity chips (e.g., -165 dBm or better) are essential for maintaining signals in 'urban canyons' or under dense foliage. For IoT devices, Power Consumption in sleep and tracking modes is critical to maximize battery life.