Migration Speeds & Performance

Migration Time

The speed and duration of the migration not only vary across environments and migration types but even across individual batches. They are also modified by bandwidth, throttling, permissions, mailbox size, and contents. As such, we do not attempt to predict duration or give specific timelines.

However, there are ways to guarantee that migration is as efficient and streamlined as possible for the given scenario. The following information is generalized, and unless specifically noted for a type or environment, applicable across many migrations. More specific details may appear in individual migration guides as well.

As always, we encourage you to thoroughly read and follow the migration guide and supporting documents. Even if something doesn’t appear to be specific to the speed of a migration, the proper planning and implementation is the necessary foundation for any migration to run efficiently.

We always recommend running a trial migration before the full migration. This is a small migration that will help establish speeds and bottlenecks, and give you the chance to troubleshoot problem spots. 

Stopping and Starting a Migration

Stopping a migration and starting it again will not improve speeds, you’ll merely lose the progress you’ve made. If a migration seems to be slower than it should be, check the documentation again to ensure everything was set up properly. If it was, leave the migration running and contact support for assistance.

Factors in Migration Speeds

Network Speed

How fast are the source and destination servers connected to the internet? The entire process is only as fast as the slowest link. MigrationWiz can connect to networks that range from a T1 to networks that host multiple gigabit connections but depending on the data center the migration server is in, we will most likely be connected with a gigabit or 10-gigabit connection. This distinction will help you plan the appropriate duration for your migration.

Be aware as well of any large projects other teams in the company may be running. If bandwidth is being used by a company-wide video conference, for example, it may impact performance. 

Server Load

What type of equipment do the source and destination run on? This is especially important for migrations involving on-premises or older environments.


MigrationWiz never throttles data. We use some of the largest existing migration servers, allowing us to maintain consistent workloads. However, there are hosts and environments that do throttle data. Our Exchange migration documentation, for example, contains information on preventing or reducing throttling for large migrations.

Before beginning a migration, it is important to discover whether your source or destination environments will throttle the migration, as this may affect the preparation steps.

Number and Size of Items

A large migration with little item enumeration may be completed quickly, while an apparently smaller migration with deep folder enumeration or complex permissions may take significantly longer to perform.

We suggest identifying the largest 50 to 75 items and creating a smaller batch of these to migrate first. This should enable the rest to process more quickly. Migrating them first ensures you don’t get to the end of the migration period and run into throttling or issues.

If you have more than 1000 items, we similarly suggest breaking your migration into multiple batches of 500 to 1000 items. This will allow for faster identification of issues, as well as avoiding slowdowns.

Network Latency

The network latency depends on the connection quality between our data center and the source and destination. We utilize the fastest internet backbones available globally. Because of our global migration farm, our connections are made from networks with low latencies.

However, different providers will have different latencies. Be aware also of high-use periods or events going on nearby.

Sample migration speeds

Here is a very rough breakdown of what your speeds may look like. This is not an SLA; it is an example based on a very large sample of migration speeds experienced by our partners. Some migrations – especially those with complex folder structures or extensive permissions – may be slower than shown here.

  • Low end: 250 MB per h/per user
  • Mid end: 750 MB per h/per user
  • High end: 1.25 GB per h/per user


If you are running into issues with your migration, the following actions may help solve the problems. 

  • Identify large or complex folders and run them in a separate batch.
  • Separate items into batches of up to 1000 individual items. 
  • Run permissions separately. 
  • Verify that the destination folders are set up correctly.
  • For on-premises Exchange, disable throttling.


Migrations have many unpredictable elements. Set yourself up for success before launching the migration by following the steps below. 

  1. Verify bandwidth from both source and destination environments.
  2. Read the migration guide and supporting documentation carefully.
  3. Identify any unusually large items that will need to be moved.
  4. Leave yourself more time than you think you’ll need for the migration.
  5. Perform a proper POC or pilot migration. If your test mimics your production environment, it will help set expectations for the migration. This also offers a chance to troubleshoot connections, firewall issues, and throttling. 
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