Video retention calculator

Cameras, bitrate and capacity

How long a crash hardened memory module holds video depends on three things: how many cameras write to it, at what bitrate, and how much capacity the module holds. Three retention figures are worth checking a configuration against: 12 hours under 49 CFR 229.136(a)(4), 48 hours under APTA RT-OP-RP-024-19, and 48 hours under the Canadian Locomotive Voice and Video Recorder Regulations, SOR/2020-178. Most configurations below exceed all three by days.

Cameras 2

Bitrate per camera 3.8 Mbps

Capacity 883 GB

—Days of continuous recording

—Hours of continuous recording

—Aggregate write rate, Mbps

—GB written per hour

The CHM86 sustains about 90 Mbit/s (11 MB/s) of continuous write, validated across extended test campaigns. Plan against 80 Mbit/s aggregate across all channels, which keeps about 10 per cent in hand for concurrent activity and file export. Bandwidth is rarely the limit before capacity is.

Made in the USA

All CHM Modules are Manufactured in the USA - FTA Buy America compliant

Reference bitrates

Configuration	Typical bitrate	Typical use
1080p / 30 fps / H.264	4–8 Mbps	High quality exterior
1080p / 15 fps / H.264	2–4 Mbps	Moderate quality
720p / 30 fps / H.264	2–4 Mbps	Reduced resolution
720p / 15 fps / H.264	1–2 Mbps	Interior, passenger area
720p / 5 fps / H.264	0.5–1.0 Mbps	FRA minimum, operator camera
1080p / 30 fps / H.265	2–5 Mbps	Next generation high quality

^{Indicative ranges for surveillance-grade IP cameras. Actual bitrate varies with manufacturer, scene complexity and encoder settings.}

Send us the schedule

Give us your camera count, bitrates and required retention and we will confirm the model and capacity.

support@deuta-america.com