Best Surveillance HDD for 4K Cameras: Complete Storage Guide (2026)
Quick Answer+
Quick Answer: 4K cameras use 2-3x more storage than 1080p — plan for 40-80GB per camera per day with continuous recording. For an 8-camera 4K system with 30-day retention, you’ll need 10-12TB minimum. The best drives are WD Purple 12TB (~$199) for standard recording or WD Purple Pro for AI-enabled 4K systems. Standard surveillance drives handle 4K bitrates fine — the challenge is capacity, not speed.
WD Purple 12TB (WD121PURZ)
12TB Capacity | 5640 RPM | 256MB Cache | CMR | 360TB/year Workload | Up to 64 Cameras | 3-Year Warranty
Optimal capacity for 4K surveillance systems. The 360TB/year workload rating handles the increased data throughput of 4K recording. Lowest $/TB in the WD Purple lineup.
4K security cameras deliver stunning detail — you can read license plates, identify faces, and capture evidence that 1080p simply can’t match. But that resolution comes with a cost: significantly higher storage requirements.
This guide covers everything you need to know about storage for 4K surveillance systems, from calculating your needs to choosing the right drives.
4K vs 1080p Storage Requirements
The jump from 1080p to 4K dramatically increases storage needs:
| Specification | 1080p | 4K (4MP) | 4K (8MP) |
|---|---|---|---|
| Resolution | 1920×1080 | 2560×1440 | 3840×2160 |
| Megapixels | 2MP | 4MP | 8MP |
| Typical Bitrate | 4-8 Mbps | 8-12 Mbps | 12-20 Mbps |
| GB/Day (H.265) | 15-25GB | 30-45GB | 45-80GB |
| 30-Day Storage (per camera) | ~600GB | ~1.2TB | ~2TB |
| Multiplier vs 1080p | 1x | 2x | 3-4x |
Key insight: A 4K system needs 2-4x the storage of an equivalent 1080p system. An 8TB drive that lasts 60 days with 1080p cameras might only last 20-30 days with 4K.
4K Storage Calculator
Quick Reference Table
| 4K Cameras | Recording Mode | 7-Day | 14-Day | 30-Day | Recommended Drive |
|---|---|---|---|---|---|
| 2 | Continuous | ~0.7TB | ~1.4TB | ~3TB | 4TB |
| 2 | Motion-only | ~0.2TB | ~0.5TB | ~1TB | 2TB |
| 4 | Continuous | ~1.4TB | ~2.8TB | ~6TB | 8TB |
| 4 | Motion-only | ~0.5TB | ~1TB | ~2TB | 4TB |
| 8 | Continuous | ~2.8TB | ~5.6TB | ~12TB | 12-14TB |
| 8 | Motion-only | ~1TB | ~2TB | ~4TB | 6-8TB |
| 16 | Continuous | ~5.6TB | ~11TB | ~24TB | Multiple drives |
| 16 | Motion-only | ~2TB | ~4TB | ~8TB | 12TB |
Based on 8MP 4K cameras, H.265 compression, 15fps. Motion-only assumes 30% activity.
Formula for Custom Calculations
Daily storage per camera:
Bitrate (Mbps) × 3600 × 24 ÷ 8 ÷ 1024 = GB/day
Example: 15 Mbps × 86,400 ÷ 8 ÷ 1024 = 158GB/day (worst case)
With H.265 efficiency: Typically 40-80GB/day per 4K camera
Best Drives for 4K Surveillance
Browse all surveillance drives suitable for 4K systems:
For Standard 4K Recording
Standard surveillance drives handle 4K bitrates without issue. The primary consideration is capacity:
| Drive | Capacity | Price | Best For |
|---|---|---|---|
| WD Purple 8TB | 8TB | ~$214.99 | 4-6 4K cameras, 30-day |
| WD Purple 12TB | 12TB | ~$299.99 | 8 4K cameras, 30-day |
| WD Purple 14TB | 14TB | ~$369.99 | 8-12 4K cameras, 30-day |
| SkyHawk 12TB | 12TB | ~$289.99 | 8 4K cameras + Rescue |
For 4K with AI Analytics
If your 4K system runs AI features (facial recognition, license plate detection, object tracking), the workload increases significantly:
WD Purple Pro 18TB (WD181PURP)
18TB Capacity | 7200 RPM | 512MB Cache | CMR | 550TB/year Workload | 64 HD + 32 AI Streams | 5-Year Warranty
Enterprise-grade for 4K AI systems. The 550TB/year workload handles constant video writing plus AI read operations. 7200 RPM improves AI query performance.
| Drive | Capacity | Workload | Best For |
|---|---|---|---|
| WD Purple Pro 12TB | 12TB | 550TB/yr | 4K + AI, up to 8 cameras |
| WD Purple Pro 18TB | 18TB | 550TB/yr | 4K + AI, 8-16 cameras |
| SkyHawk AI 16TB | 16TB | 550TB/yr | 4K + AI + Rescue service |
| SkyHawk AI 20TB | 20TB | 550TB/yr | Large 4K + AI systems |
Optimizing 4K Storage
Compression Settings
Codec choice dramatically affects storage:
| Codec | 4K Storage/Day | Savings vs H.264 | Compatibility |
|---|---|---|---|
| H.264 | 80-120GB | — | Universal |
| H.265 (HEVC) | 40-60GB | ~50% | Most modern NVRs |
| H.265+/Smart H.265 | 20-40GB | ~70% | Brand-specific |
Recommendation: Always use H.265 for 4K cameras. The storage savings are substantial with no visible quality loss.
Recording Mode Strategies
- Continuous 4K: Maximum quality but highest storage (use for critical areas)
- Motion-triggered 4K: Reduces storage 50-70% (good for most applications)
- Hybrid: Continuous sub-stream + motion-triggered 4K (balanced approach)
- Scheduled: 4K during business hours, lower resolution overnight
Frame Rate Considerations
| Frame Rate | Storage Impact | Use Case |
|---|---|---|
| 15fps | Baseline | Most surveillance (recommended) |
| 20fps | +33% | Moderate motion areas |
| 30fps | +100% | High-speed capture (sports, traffic) |
Note: 15fps captures 4K video smoothly for most security purposes. Only increase for specific high-motion scenarios.
4K System Configurations
Home 4K System (4 cameras)
- Cameras: 4x 4K (8MP)
- Recording: Motion-triggered, H.265, 15fps
- Retention: 30 days
- Storage needed: ~2-3TB
- Recommended:WD Purple 4TB (~$129.00) or 8TB for growth
Standard 4K System (8 cameras)
- Cameras: 8x 4K (8MP)
- Recording: Continuous, H.265, 15fps
- Retention: 30 days
- Storage needed: ~10-12TB
- Recommended:WD Purple 12TB (~$199)
Business 4K System (16 cameras)
- Cameras: 16x 4K (8MP)
- Recording: Continuous, H.265, 15fps
- Retention: 30 days
- Storage needed: ~20-24TB
- Recommended: 2x WD Purple 14TB (~$739.98) or RAID
4K + AI System
- Cameras: 8x 4K with facial recognition
- Recording: Continuous + AI analytics
- Retention: 30 days
- Storage needed: 12-18TB
- Recommended:WD Purple Pro 18TB (~$389.99)
Can Standard Drives Handle 4K Bitrates?
Yes. This is a common misconception. Here’s why:
Drive Speed vs 4K Requirements
| Metric | 4K Requirement | WD Purple Capability |
|---|---|---|
| Single 4K stream | ~2.5 MB/s | 190+ MB/s |
| 8 simultaneous 4K streams | ~20 MB/s | 190+ MB/s |
| 16 simultaneous 4K streams | ~40 MB/s | 190+ MB/s |
Even budget surveillance drives have ~10x the throughput needed for 4K recording. The limitation is always capacity, not speed.
When Speed Matters
Drive speed becomes relevant only for:
- AI analytics (random reads during video analysis)
- Multiple simultaneous playback sessions
- Video export/backup operations
For these workloads, WD Purple Pro (7200 RPM) offers improved performance.
4K Storage Maintenance
Monitoring Drive Health
4K systems work drives harder. Monitor:
- Temperature: Keep below 45°C (install fans if needed)
- SMART data: Watch for reallocated sectors
- Workload: Verify you’re within drive ratings
- Capacity: Don’t exceed 90% utilization
When to Add Storage
- Retention period is shorter than desired
- Adding more 4K cameras
- Switching from motion-only to continuous
- Drive approaching capacity limits
Frequently Asked Questions
Plan for 40-80GB per 4K camera per day with continuous recording (H.265). An 8-camera 4K system needs approximately 10-12TB for 30-day retention . Motion-only recording reduces this by 50-70%.
No. Standard surveillance drives (WD Purple, SkyHawk) handle 4K bitrates easily — they have ~10x the throughput needed. The main consideration is capacity, not speed. Choose larger drives (8TB+) for 4K systems.
For 4-6 cameras with continuous recording, 8TB provides about 30 days of retention. For 8+ cameras or longer retention, upgrade to 12TB or 14TB . Motion-only recording can make 8TB sufficient for more cameras.
Always use H.265 (HEVC) for 4K surveillance. It reduces storage requirements by approximately 50% compared to H.264 with no visible quality difference. Most modern NVRs and cameras support H.265.
Standard WD Purple is sufficient for 4K recording without AI. Upgrade to Purple Pro only if running AI analytics (facial recognition, object detection) on 4K footage — the constant read operations during AI processing benefit from the higher workload rating and 7200 RPM.
Yes. Your NVR handles mixed resolutions automatically. Calculate total storage by adding the requirements for each camera type. The drive doesn’t care about resolution — it just writes the data streams it receives.
Related Guides
Drive Reviews:
Tools:
Buying Guides:
Last updated: February 2026. Storage calculations based on typical 4K camera bitrates with H.265 compression.
