Speed comparison: real-world impact
**HDD**: 150-220 MB/s read, mechanical. Boot: 30-40 seconds. Apps: 5-10 seconds to launch. **SSD**: 500-7,450 MB/s read, instant. Boot: 5-10 seconds. Apps: <1 second. **Real gaming impact**: SSD loads games 3-5 seconds faster. HDD causes longer load screens. Not a dealbreaker for single-player, annoying for multiplayer.
Cost per TB: HDDs still win at large capacities
**1TB SSD**: $70-100 per TB. **2TB SSD**: $60-80 per TB. **4TB SSD**: $50-70 per TB. **4TB HDD**: $15-25 per TB (3-5× cheaper). **8TB HDD**: $12-18 per TB. **20TB HDD**: $10-15 per TB. **Reality**: SSD is now competitive at 1-2TB. HDD dominates for 4TB+ archival.
Reliability: MTBF and lifespan
**SSD**: 1.5-2M hour MTBF (mean time before failure). Write endurance: 300-1000 TBW (terabytes written). Lasts 5-10 years typical use. **HDD**: 1.2-2M hour MTBF. Lasts 4-7 years. Failures often sudden (no warning). **Verdict**: Both equally reliable. SSDs outlast HDDs in heavy use due to mechanical wear.
When to buy SSD vs HDD
**Buy SSD when**: - OS/boot drive (critical) - Gaming (load times matter) - <4TB capacity - Active use (frequent access) **Buy HDD when**: - Archival (photos, old videos) - Backup redundancy (RAID mirrors) - 4TB+ capacity (cost-prohibitive as SSD) - Cold storage (rarely accessed)
Optimal multi-drive setup
**Best practice**: 500GB-1TB SSD for OS + games. 4TB HDD for archive + backups. **Why**: Fast system, cheap archive. Total cost: $120-200 for both. **Alternative**: All SSD if budget allows (simpler, faster, future-proof).