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Planning large installations of PRTG Network Monitor



What do I have to take into account when planning a large installation of PRTG?

install installation large planning prtg siteplanner

Created on Oct 13, 2011 10:21:36 AM by  Daniel Zobel [Product Manager]

Last change on Jan 17, 2023 7:40:56 AM by  Brandy Greger [Paessler Support]

13 Replies

Accepted Answer



This article applies as of PRTG 22

Planning large installations of PRTG

The maximum number of sensors that you can monitor with one installation of PRTG mainly depends on the monitoring technology and the scanning intervals that you use. See also the system requirements that show recommended sensor counts for an ideal setup.

  • SNMP v1/v2c, Ping, Port, and HTTP are the recommended types of sensors for scenarios with thousands of sensors.
  • SNMP v3 has performance limitations because of the use of encryption. Furthermore, keep in mind that SNMP v3, unlike SNMP v1 and v2c, does not scale with more CPU power. Because of this limitation, you can monitor only a limited number of sensors per second.
  • For WMI monitoring, try to keep the number of WMI sensors per probe below 120 (with a 60-second scanning interval) or 600 (with a 300-second scanning interval).
  • For flow (NetFlow, sFlow, jFlow) monitoring, the maximum number of sensors depends on the traffic pattern, the number of flow packets received by the probe per second, as well as the performance of the probe system.
  • Packet sniffing creates the highest CPU load on the probe system. This technology is only recommended for monitoring low traffic connections (<50 Mbit/s steady stream). If traffic often goes beyond 10 Mbit/s, use a dedicated remote probe.
  • For best performance of VMware sensors, we strongly recommend Windows Server 2012 R2 on the probe system with the VMware sensors. On this operating system, you can use up to 300 VMware sensors with a 60-second scanning interval. See the article How can I increase the connection limit on VMware systems? for details.

To overcome any limitations mentioned above, distribute the sensors over multiple remote probes.

As a rule of thumb, you should not experience any performance issues if you stay below 5,000 sensors, below 30 remote probes, and below 30 user accounts. If the installation is planned well, PRTG can scale much higher.

For the high-speed operation of the PRTG web interface (page loading times below 500ms), we recommend that you stay below 5,000 sensors per installation. For clusters we recommend that you stay below 2,500 sensors per cluster.

If you plan an installation with more than 5,000 sensors on a physical system, or if you want to set up more than 5,000 sensors on a virtual machine, please contact our Presales team for consultation. They will advise you on sensor limits and scanning intervals. See also our Best Practice Guide: Running large installations of PRTG in a virtual environment.

Performance can also vary depending on the number of channels per sensor.

Note: Sensors with more than 50 channels are not officially supported and can have a high impact on system performance.

For more information, see also the PRTG Manual: System Requirements.


Created on Oct 13, 2011 10:35:23 AM by  Daniel Zobel [Product Manager]

Last change on Jan 18, 2023 9:56:56 AM by  Brandy Greger [Paessler Support]



I'd like to add to this comment that it is possible to use more than 120 sensors for WMI. I think our current setup is approximately running a total of 1200 sensors (60 sec interval) with about 250 wmi sensors and we will be adding more of them.

We are however running this single server install on a dual xeon x5660 @ 2.6ghz 12 GB ram machine with a 1gb FBWC raid controler.

In this setup I have 24 cpu's according to task manager. CPU usage is light as well as memory usage.

I don't have jFlow working yet (due to a limitation on the SRX 240 not being able to send out jFlow on reth interfaces) so my main sensors are ping, snmp (v2) and WMI.

This is all local Lan so al latencies are <10ms and I have not had any performance issues. the troubles I've had with WMI are usually due to the fact that we have a lot of win2k8 (non r2) servers which pretty much hate WMI altogether.

Created on Oct 13, 2011 2:52:30 PM

Last change on Oct 13, 2011 3:05:02 PM by  Daniel Zobel [Product Manager]



Well... it is actually possible to run 60K sensors on single core server install. In our install: 54K of them are snmp traffic sensors, 2k pings and the rest are mostly WMI, distributed across multiple probes. Server config: Cisco UCSC-C220-M3S, 2x E5-2690 v2@3GHz, 64GB RAM, 10K disks in RAID10, windows server 2012 R2 dtc. This includes hyper-v role, and 2 2k12r2 VM's, where most loaded probes are hosted. Problems: very large config file, around 4gb. Slow to apply config changes. I hope Paessler will do something about the way prtg stores config, so we can add even more sensors :)

Created on May 14, 2014 8:33:18 AM



Well, qurvax, that's an impressive installation!

Created on May 20, 2014 4:30:52 PM by  Dirk Paessler [Founder Paessler AG] (11,025) 3 6



Hi qurvax,

Thank you for sharing the information. Well , I am currently trying to convince my team to move away from cron based mrtg to PRTG , if we do I will be putting in approximately 2,74,280 snmp sensors. I am planning to spread them over probes ( May be 15+ ) , Would you recommend such large installation ?


Created on Nov 26, 2014 9:01:01 AM



If you are planning to use more than 10,000 sensors, I'd recommend to split the load to several core servers and use the Enterprise Console to administer each server. This will keep your installation healthy.

Created on Nov 27, 2014 2:39:01 PM by  Felix Saure [Paessler Support]

Last change on Dec 5, 2018 12:41:04 PM by  Felix Saure [Paessler Support]



For some type of PRTG Sensors is recommended that we use not more than 50 (for WBEM or SOAP) or 200 (for WMI) sensors on each probe. Does it mean that we should use for example only 50 WBEM sensors on a probe with no other type of sensor or you Considered having other types beside this 50 sensors? Is it possible to have 50 SOAP Sensors+120 WMI Sensors+40 WBEM Sensors all together on a probe?What does it mean?

Created on May 9, 2015 4:19:27 AM



I have to agree with Qurvax, please get rid of the flat xml config file. It seems to be the only thing that's slows us down is any config changes because of the file size. We have 20k sensors and a 1gb config file. Configuration changes are slow. If your not modifying any configurations the server seems to be fairly fast.

Created on Jul 2, 2015 10:24:56 PM



@AJamshidi: on Recommended number of Sensors per Probe

Generally spoken the recommendations that you find for each Sensor Type only apply to this Type, that means you can combine several Sensors and use those recommendations. Of course, you will also run into performance issues when you start exhausting those limits for alot of Sensors on a Probe, hence always try to balance the whole setup on a Probe, in order to keep a good performance.

Created on Jul 3, 2015 9:02:10 AM by  Andreas Heidrich [Paessler Support] (51) 2 1



Is there a good rule of thumb for number of sensors that should be distributed to each remote probe?

Created on Dec 11, 2019 4:43:56 PM



Hey ryankane1,

In general, we recommend to keep the amount of sensors per probe device (local/remote/cluster) below 2,500 (with a mixed setup of sensor types).

Best regards,
Sven Roggenhofer [Paessler Technical Support]

Created on Dec 12, 2019 5:58:16 AM by  Sven Roggenhofer [Paessler Technical Support]



Is there a updated Version of this Post ?

Created on Feb 9, 2023 11:56:34 AM




We do not have a newer version of this article, however the points mentioned here do apply to the newer versions of PRTG as well.

Kind regards,
Sasa Ignjatovic, Tech Support Team

Created on Feb 13, 2023 8:12:09 AM by  Sasa Ignjatovic [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.