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CrashPlan Support

Using CrashPlan With Limited Bandwidth

Applies to:
  • CrashPlan for Home
Need enterprise or small business documentation?
This article is intended for CrashPlan for Home users. For Code42 CrashPlan and CrashPlan for Small Business documentation, read this page on our enterprise support site.


CrashPlan is designed to make minimal demands on your computer's resources, and favors quiet background operation over outright speed. There may be times that you need to reduce the bandwidth you allow CrashPlan to use, such as:

  • If you have limited bandwidth or a bandwidth cap.
  • If you are using voice over IP (VoIP).
  • If CrashPlan backup activity is competing with other network applications, and you would prefer to allocate more bandwidth to those applications.

This article outlines some adjustments that allow CrashPlan to use less bandwidth, as well as some items to consider before changing any settings.


  • By adjusting the settings described below, CrashPlan will use less bandwidth, but it also slows down your backup.
  • Results of changing settings may not be immediately apparent. You may need to wait a short time before noticing improvements.
  • You can return to the default backup settings at any time.
Backing Up Locally And Online
We recommend configuring CrashPlan to back up to more than one destination. Usually, one destination is local, such as an external hard drive, and one destination is off-site, such as CrashPlan Central. Backing up to a local drive is generally faster and ensures that your files are safely backed up even as your offsite backup is in process.

Before you begin

Review your file selection to ensure that you have only selected files that you need to back up. Backing up system files or application data can dramatically increase your bandwidth usage.


By default, CrashPlan has limits in place to prevent it from using too many system resources. If you have limited bandwidth, a bandwidth cap, or utilize VoIP, there are several settings you can adjust in the CrashPlan app to reduce the impact of CrashPlan on your bandwidth. Changing these settings to reduce the system resources available to CrashPlan extends the amount of time required to backup your files.

Changing Settings
Explore the options below in the order presented. If you see adequate reduction in speed after one or two changes, avoid making additional changes.

Backup scheduling

If there are certain times of day during which you want to reduce CrashPlan's bandwidth usage, you can schedule specific days and times that you want CrashPlan to back up. For example, you may want to schedule backups to occur overnight, when you aren't using the Internet.

To schedule your backup:

  1. Open the CrashPlan app and select Settings > Backup.
  2. Change Backup will run to Always.
  3. Select the days and hours when CrashPlan is allowed to back up.
    CrashPlan cannot run if your computer is off or asleep. You may need to optimize your energy settings to ensure CrashPlan can operate during the selected time periods.

Backup Scheduling

  1. Click Save.

CPU settings

  1. Open the CrashPlan app and select Settings > General.
  2. Decrease the percentage of CPU that CrashPlan is allowed to use when the user is both away and present. Start by decreasing each to 20%. You can always scale back CPU usage even more if CrashPlan interferes with your work.
    Note: In Linux, CrashPlan always uses the "Away" setting.

CPU Settings

  1. Click Save.

How Does CrashPlan Know I'm Away?
The CrashPlan app uses keyboard and mouse activity to detect if you are present or away from your computer.

Frequency settings

(CrashPlan for Home subscribers only)

CrashPlan assumes that what you're working on now is most important, so it prioritizes your most recently changed files to back them up first.

For CrashPlan for Home subscribers, the default setting is to back up new information every 15 minutes. This offers great protection for backing up your files right away and allows you to easily revert to a previous version of a file. However, it also means that CrashPlan uses some resources to back up recent versions of your files as you work.

Changing the backup frequency settings is most helpful for large backups and for file selections with very large files. Extending the default backup frequency time allows CrashPlan to work through your files without the the additional workload of backing up multiple versions of your files. The trade-off to extending the backup frequency time is that your new files and changes won't be backed up as quickly.

To increase the time between backups:

  1. Open the CrashPlan app and select Settings > Backup > Frequency and versions > Configure.
  2. Click Configure from Frequency and versions.
  3. Click and drag New version to a longer period, such as every 8 hours.

Backup Frequency Settings

Network settings

  1. Select Settings > Network from the CrashPlan app.
  2. Change Limit sending rate when present or Limit sending rate when away as needed.
    • WAN settings apply to transferring data over the Internet; LAN settings apply to transferring data to other computers in your local network.
    • Start by setting the limits to 100 kbps. If CrashPlan is still using too much bandwidth, try decreasing it further by selecting Custom and setting the value lower than 100.
      Minimum Recommended Sending Limits
      When setting network sending limits, do not set a rate lower than 0.10 Mbps or 100 Kbps. Rates lower than 0.10 Mbps can prevent devices from communicating with the Code42 server, which can stop backups. To stop backup entirely, do not adjust sending limits. Instead, you can pause backup or only allow backups at specified times.
    • Do not adjust the settings for message buffer size settings, which have no impact on your bandwidth. These are advanced networking settings intended for advanced users only.

Network Settings

  1. Click Save.