NTP time server or PTP grandmaster? NTP100 series vs GMR series
Two families, one decision. The compact NTP100 series delivers the time via NTP over your network. The GMR series does that too, but adds PTP (IEEE 1588), time code generation and network redundancy. This page helps you choose based on protocol, scale and application, with a factual comparison based on the current datasheets.
The short recommendation
- Choose an NTP100 time server if you need NTP for a network of up to a few dozen clients, without PTP and without time code generation. Compact, one port, with GNSS (NTP100-GNSS), oscillator (NTP100-OSC) or time code input (NTP100-TC) as the source.
- Choose a GMR grandmaster as soon as you need PTP, want to generate and distribute time code (IRIG-B, SMPTE), want several independent NTP ports or higher scale, or require redundant power. The GMR6000 adds the IEC 61850-9-3 Power Profile for digital substations.
NTP100 series vs GMR series side by side
| Feature | NTP100 series | GMR series |
|---|---|---|
| Role | NTP client / server | PTP grandmaster + NTP server + time code generator |
| NTP output accuracy | ± 2 ms | ± 2 ms (NTP), sub-µs via PTP |
| PTP (IEEE 1588) | No | Option (GMR1000/5000), standard on GMR6000 (1588-2019) |
| Generate time code (IRIG-B / SMPTE) | No (NTP100-TC accepts time code as input) | Yes (optional) |
| NTP ports | 1× RJ45 10/100 Mb | 1× (GMR1000) up to 4× 1 GbE + 2× 10 GbE (GMR6000) |
| Time source | GNSS, internal oscillator, or time code (per model) | Multi-GNSS + internal oscillator |
| Holdover oscillator | TCXO ± 3 s/year, OCXO ± 250 ms/year (option) | OCXO or Rubidium (multi-day) |
| Power | DC 9-28 VDC + external 12 VDC adapter | AC/DC, hardware-redundant on GMR6000 |
| Display | 6-digit LED | Optional/13-digit/web (per model) |
| Consumption | < 7.5 W | Model-dependent |
| Warranty | 1 year Daylight + 4 years Masterclock | 1 year Daylight + 4 years Masterclock |
When do you choose what?
NTP100 series — compact, focused NTP source
The NTP100 is intended for the classic need: a reliable Stratum-1 time source that distributes NTP over the network. It is compact (about 16 cm wide), consumes little, and delivers an output accuracy of ± 2 ms. The choice between the variants depends on the source: satellite (GNSS), an internal oscillator, or a supplied time code. For offices, schools, hospitals, smaller data centres and most IT networks this is more than enough.
GMR series — grandmaster with PTP and time code
As soon as PTP comes into play (broadcast, exchange trading, 5G fronthaul, digital substations) or when you must generate and distribute IRIG-B or SMPTE, a GMR grandmaster is the right choice. The GMR1000 is the compact entry, the GMR5000 the expandable 1U workhorse, and the GMR6000 the substation-grade top with Power Profile, dual 10 GbE and redundant power. A GMR moreover serves PTP and NTP at once, so critical and ordinary equipment run from one source. For the choice within the GMR family: see the GMR comparison.
Frequently asked questions
What is the difference between an NTP time server and a grandmaster?
An NTP time server (NTP100 series) delivers the time via NTP over the network to clients, to within a few milliseconds. A grandmaster (GMR series) does that too, but can additionally deliver PTP (IEEE 1588) for sub-microsecond synchronisation and generate and distribute time code (IRIG-B, SMPTE). The grandmaster is the broader, more powerful source; the NTP100 is the compact, focused solution.
From how many clients do I need a GMR?
For a simple network of up to a few dozen NTP clients, an NTP100-GNSS or NTP100-OSC is enough. For larger numbers, mixed NTP traffic, or when you want several independent NTP ports or redundant power, you move to a GMR grandmaster. For PTP a GMR is required anyway.
Can the NTP100 generate PTP or time code?
No. The NTP100 series is an NTP client/server; it does not deliver PTP and does not generate IRIG-B or SMPTE time code. The NTP100-TC can use time code as an input to synchronise to. If you want PTP or time code generation, you need a GMR grandmaster.
What is the difference between NTP100-GNSS, NTP100-OSC and NTP100-TC?
The NTP100-GNSS synchronises to satellites (Stratum 1) via a supplied antenna. The NTP100-OSC has no GNSS and relies on an internal precision oscillator (TCXO standard, OCXO optional). The NTP100-TC synchronises to a supplied time code (IRIG/SMPTE). All three deliver NTP with an output accuracy of ± 2 ms.
Can one device deliver both NTP and PTP?
Yes, a GMR grandmaster can serve as a PTP grandmaster and NTP server at the same time. This lets you serve critical PTP equipment and ordinary NTP clients from one source. The NTP100 series does NTP only.
Not sure? Daylight bv has been the official Masterclock distributor since 2014. We advise you independently based on clients, protocol and holdover requirements.
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