Buyers must prioritize DDR generation (DDR4 vs. DDR5) to ensure compatibility with modern motherboards. Key metrics include Frequency (MHz), where higher speeds like 4800MHz+ are standard for DDR5, and CAS Latency (CL), which dictates data access speed. For server-grade applications, ECC (Error Correction Code) is mandatory to prevent data corruption. Always verify the chip brand (e.g., Samsung, SK Hynix, Micron) as these 'Tier 1' manufacturers offer the highest reliability and lowest failure rates.