Storage Planning Calculations

Updated

How much space a shoot needs: gigabytes per hour from the bitrate, footage from the shooting ratio, proxies and headroom, backup copies, usable RAID capacity, and how long the copies take.

Storage Requirements Reference

Gigabytes per Hour

1080p at 25 Mbps

~11GB/hour

HD delivery file: 25 × 0.45 = 11.25 GB per hour

UHD at 100 Mbps

~45GB/hour

Long-GOP camera file: 100 × 0.45 = 45 GB. Size follows bitrate, not resolution

UHD ProRes 422

~212GB/hour

3840×2160 at 24p, 471 Mbps (Apple ProRes white paper)

UHD ProRes 422 HQ

~318GB/hour

3840×2160 at 24p, 707 Mbps (Apple ProRes white paper)

ProRes at 1080p

ProRes 422 Proxy

36-45 Mbps

16-20 GB per hour at 24p-30p; the usual offline proxy

ProRes 422

117-147 Mbps

53-66 GB per hour at 24p-30p

ProRes 422 HQ

176-220 Mbps

79-99 GB per hour at 24p-30p

ProRes 4444

264-330 Mbps

119-148 GB per hour at 24p-30p, before any alpha channel

Beyond the Camera Files

Proxies

Proxy ÷ camera rate

1080p ProRes Proxy is 5% of UHD ProRes 422 HQ, but 36% of a 100 Mbps camera file

Backups

× copies

3-2-1 means three copies in all: the working copy and two backups

RAID

n − 1 or n − 2 drives

RAID 5 gives up one drive's capacity to parity, RAID 6 two

Drive labels

TB vs TiB

A 16 TB drive is 14.55 TiB, so it looks smaller where the system counts in binary

Shooting Ratios by Production Type

Rough, commonly quoted ranges: the minutes shot for every finished minute. Real projects vary widely, so use your own numbers when you have them.

Commercial

Shoot Ratio:

5:1 to 10:1

Controlled environment with planned shots

Footage per Finished Minute:

27-53 GB

At UHD ProRes 422 HQ, 24p (5.3 GB per minute shot)

Narrative

Shoot Ratio:

8:1 to 15:1

Multiple takes and coverage angles

Footage per Finished Minute:

42-80 GB

At UHD ProRes 422 HQ, 24p (5.3 GB per minute shot)

Documentary

Shoot Ratio:

15:1 to 30:1

Extensive coverage and interview material, and often far more

Footage per Finished Minute:

80-159 GB

At UHD ProRes 422 HQ, 24p (5.3 GB per minute shot)

Storage Planning Calculations

Camera Footage from Shooting Ratio

Start from the finished running time and how much you expect to shoot for every minute that ends up on screen.

Formula:

Footage (GB) = Finished Runtime (hours) × Shooting Ratio × GB per Hour

Examples:

90-minute feature, 10:1, UHD ProRes 422 HQ at 24p

Calculation: 1.5 × 10 × 318 = 4,770 GB

Result: 15 hours of footage, about 4.8 TB

30-minute documentary, 30:1, 1080p ProRes 422 HQ at 24p

Calculation: 0.5 × 30 × 79 = 1,185 GB

Result: 15 hours of footage, about 1.2 TB

Tips:

  • Count every camera in the ratio: two cameras rolling on every take double the footage
  • Take the ratio from your own past projects where you can; the ranges above are only a starting point

Project Storage

Add proxies to the camera footage, then leave headroom for renders, cache, exports and anything unplanned.

Formula:

Total = (Footage + Camera Hours × Proxy GB per Hour) × (1 + Headroom)

Examples:

The 15-hour feature, 1080p ProRes Proxy, 20% headroom

Calculation: (4,770 + 15 × 16.2) × 1.2 = 6,016 GB

Result: About 6 TB of working storage

20 hours of 100 Mbps footage, same proxies and headroom

Calculation: (20 × 45 + 20 × 16.2) × 1.2 = 1,469 GB

Result: About 1.5 TB; here the proxies add 36%

Tips:

  • Proxies cost little against high-rate camera files and a lot against compressed ones
  • Size the headroom from what renders and cache took on your last similar project

Bitrate to Storage

Convert a video bitrate to storage over time (1 GB = 8,000 megabits).

Formula:

Storage (GB) = Bitrate (Mbps) × Duration (minutes) × 60 ÷ 8,000

Examples:

100 Mbps for 2 hours

Calculation: (100 × 120 × 60) ÷ 8,000 = 90 GB

Result: 90 GB storage needed

25 Mbps for 8 hours

Calculation: (25 × 480 × 60) ÷ 8,000 = 90 GB

Result: 90 GB storage needed

Tips:

  • Storage grows in direct proportion to bitrate: double the bitrate, double the storage. The free bitrate calculator works it out in your browser
  • Published codec rates are targets, and real files land a little either side, so round up
  • Add the audio: it is small next to camera video but not zero

Backup Storage

Every copy needs its own space. The 3-2-1 rule (as CISA puts it) is three copies of anything important, one primary and two backups, on two types of media, with one copy offsite.

Formula:

Total Storage = Project Size × Number of Copies

Examples:

6 TB project under 3-2-1

Calculation: 6 × 3 = 18 TB

Result: 18 TB in all: 6 TB working, 12 TB of backups

2 TB shoot day, copied to two shuttle drives before the cards are wiped

Calculation: 2 × 2 = 4 TB

Result: 4 TB of shuttle drives per shoot day

Tips:

  • Wipe a camera card only after its copies are verified
  • A RAID counts as one copy, however many drives it has
  • For the archive copy, the LTO archiving guide covers tape counts and write time

RAID Usable Capacity

Parity and mirroring cost capacity. For n drives of size d:

Formula:

RAID 0 = n × d; RAID 5 = (n − 1) × d; RAID 6 = (n − 2) × d; RAID 10 = n ÷ 2 × d

Examples:

8 × 16 TB drives, RAID 5 or RAID 6

Calculation: (8 − 1) × 16 = 112 TB; (8 − 2) × 16 = 96 TB

Result: RAID 6: 96 TB, shown as 87.3 TiB where the system counts in binary

8 × 16 TB drives, RAID 10

Calculation: 8 ÷ 2 × 16 = 64 TB

Result: 64 TB, half the raw capacity

Tips:

  • RAID 5 survives one failed drive, RAID 6 two, RAID 0 none; the RAID capacity guide covers rebuild time and risk
  • RAID guards against a failed drive, not against deletion, corruption, theft or fire: it is not a backup
  • The free RAID capacity calculator compares every level for your drives in your browser

Transfer Time

Work out how long a copy takes from the link speed, then check the drives can keep up with it.

Formula:

Transfer Time (seconds) = File Size (GB) × 8,000 ÷ Speed (Mbps)

Examples:

100GB over Gigabit Ethernet (1,000 Mbps)

Calculation: 100 × 8,000 ÷ 1,000 = 800 seconds

Result: About 13 minutes at line rate, nearer 14 in practice

500GB over USB 3.0 (5 Gbps signalling, 500 MB/s ceiling, about 400 MB/s in practice)

Calculation: 500 × 8,000 ÷ 3,200 = 1,250 seconds

Result: About 21 minutes transfer time

Tips:

  • The slowest part sets the speed: a single hard drive can be slower than the port it is plugged into
  • Offload software that verifies each copy reads the data back, so allow time for that too (see card offload time)
  • Quote speeds in one unit: 400 MB/s is 3,200 Mbps
  • For uploads, the free upload time calculator gives the time at your connection speed in your browser