How long will the initial backup take?


Written By Tami Sutcliffe (Super Administrator)

Updated at April 12th, 2022


How long the initial backup/upload will take depends on several factors, including:

  • Amount of data to backup
  • Number of files to backup
  • Upload bandwidth (speed) of the client Internet connection
  • Latency (delay) of the client Internet connection

This article will help you estimate how long the initial backup will take based on these factors.

NOTE: In the case of volume-based or image-based backup solutions like x360Recover, the amount of time the initial backup takes depends on the size of the compressed, deduplicated data and not on the number of files (since it is volume-based). 

Upload speed test

To accurately estimate how long it will take you to upload your data, you should first test to see how fast you can upload data to the Internet. (For some connections, such as broadband connections, your upload speed is usually less than the download speed advertised by your ISP.)

NOTE: Make sure to run the upload test from the site where replication of the backup data will be taking place!

To test your upload connection speed while a backup is NOT running, please click here.

For information about how to interpret the speed test, please review this article:

Estimate by total amount of data

The following table can help you estimate how long it will take to backup your data, based on the total amount of data to backup and your Internet upload speed.

Amount of data 1 GB 5 GB 10 GB 25 GB 75 GB 200 GB 500 GB
128 Kbits/sec
(Slow Broadband Connection)
19 hrs 3.9 days 7.7 days 19 days 57 days 152 days 380 days
300 Kbits/sec
(Avg. Broadband Connection)
8 hrs 1.6 days 3.3 days 8.1 days 25 days 65 days 162 days
800 Kbits/sec
(Fast Broadband Connection)
3 hrs 15 hrs 1.3 days 3.0 days 9.1 days 25 days 61 days
1,500 Kbits/sec
(T1 Connection)
1.6 hrs 8 hrs 16 hrs 1.6 days 4.9 days 13.0 days 33 days
3,000 Kbits/sec
(Bonded-T1 Connection)
0.8 hrs 4 hrs 8 hrs 20 hrs 2.5 days 6.5 days 16.5 days
10,000 Kbits/sec
(Direct Ethernet Connection)
20 min 1.2 hrs 2.4 hrs 5.9 hrs 17.5 hrs 2.0 days 4.9 days
44,000 Kbits/sec
(T3/DS3 Connection)
4 min 20 min 0.6 hrs 1.4 hrs 4.0 hrs 10.6 hrs

1.1 days

Note: This table assumes that your bandwidth throttling settings for replication (in the respective backup solution you are using) are set to maximum, for both business hours and off hours. Many businesses will need to use a lower bandwidth speed during business hours. We recommend that you set the business hours bandwidth setting to half of your measured upload rate. If you choose to do this, then it will take 33% longer than the times in the table above.

Tip for Axcient Backup For Files users: If you are using the Online Backup Manager, you can use the Visualize feature on the Folders page to determine how much data needs to be backed up to the server with your backup configuration. (After you open Visualize, watch the textbox below the folder list at the bottom of the dialog. Look for a line of text that says "Amount to backup in all folders:")

Estimate by number of files

Another consideration is how many files need to be backed up. If you are backing up mostly small files (for typical connection speeds, files that are 8 KB or less in size) then the total amount of time to perform the initial backup will mostly be determined by the number of files you are backing up and the network latency to the remote server.

The following table can be used to estimate the initial backup duration:

Number of files 50,000 100,000 1 million 3 million 5 million 10 million 50 million
Slow (100 ms) 2.0 hrs 3.9 hrs 1.6 days 4.9 days 8.1 days 16.2 days 81 days
Medium (50 ms) 1.3 hrs 2.5 hrs 25.0 hrs 3.1 days 5.2 days 10.4 days 52 days
Quick (25 ms) 0.9 hrs 1.8 hrs 18.1 hrs 2.3 days 3.8 days 7.5 days 38 days
Fast (10 ms) 0.7 hrs 1.4 hrs 13.9 hrs 1.8 days 2.9 days 5.8 days 29 days

Note that the above table factors in a pessimistic estimate on the amount of time it takes the server to safely commit one file to the data repository. Depending on the server load, the server may process the request more quickly, and the backup would take less time than estimated above. 


Your initial backup duration depends both (a) on the total amount of data to upload and (b) the number of files that must be uploaded. This article has described how to estimate the initial backup duration based on each factor. You should take the longer duration of the two estimates as the most accurate estimate for the initial upload duration.

If the estimated initial backup duration is unacceptable, then you should consider preloading the data. Please refer to the Preloading Knowledgebase for more information. 

Note: When considering a preload, you must account for shipment time + time it takes to create the preload on a disk + time it takes Axcient to process your data. Under the best circumstances, this usually takes at least 4-5 total business days (plus one business day for each additional 2TB of data). Use this as a rule when comparing preloading vs uploading your backup data.



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