By Lily / Last update August 4, 2021

Copying drives with different block sizes is not supported

"I've been running into clone problems lately with 1TB hard drives. HDClone gives me an error saying, "copying between drives with different block sizes is not supported". Clonezilla won't work either and it's really a bother to do a clean install and migration manually. Karen's Replicator is another possibility that I've considered but it's a bit time-consuming, especially with hard drives that have multiple partitions."

Cloning hard drive with different block size is a little tricky for many disk cloning software, but there are software that can do it, AOMEI Backupper Standard, for example. Continue to learn more.

Overview about copying drives with different block sizes

In the first place, you need to know what the disk block size is. In computing, a sector is a subdivision of a track on a disk. A block is actually a group of sectors. As for the disk block size, it is the size of a block in file systems and data storage.

After that, let's talk about why clone hard drive with different block sizes. There are two main reasons as below.

  • Hard drive upgrade. Users usually clone hard drive to larger drive or SSD for big capacity because of insufficient disk space. 

  • Improve computer performance. Replacing HDD with smaller SSD can be the best way to improve the performamce of a lower computer. It's simple and efficient. 

  • Backup for disaster recovery.  To prevent data from being lost, some users choose to clone the hard drive to another hard drive just in case.

Easiest way to clone hard drive with different sizes 

Copying between drives with different block sizes is not supported? Don’t worry! Your problem will be solved soon with the help of best free disk cloning software - AOMEI Backupper Standard. It allows you clone disk to larger disk and clone larger HDD to smaller SSD in simple steps. The latter one requires that target SSD has enough space to hold everything on HDD. And you can use it in Windows 7/8/8.1/10/XP/Vista.

Also, it still allows you to clone all sectors of a hard drive with "Sector by sector clone". It can greatly improve the performance of a SSD disk and extend its lifespan with "SSD Alignment". It helps you make full of disk space with "Edit Partitions" in its advanced version - AOMEI Backupper Professional, so you will cloned hard drive or SSD will show full capacity.

Well then, how to clone hard drive with different size? Read the step by step guide below and follow it.

Step by step guide: copying between drives with different block sizes

Before you start to clone disk with different size, some preparations are required.

  • Check the interface and thinkness of old hard drive before you go out to purchase a HDD or SSD.

  • Put a diet on the old HDD. Uninstall the programs you are no longer use or transfer large files like videos to another drive. 

  • Initialize the new HDD or SSD in disk management if it's not. 

  • Create a system image and save it to external hard drive, so you can prevent system failure during the cloning process. 

Then. let's get started to clone hard drive with different block size with AOMEI Backupper Standard. 

Step 1. Download, install and launch this software. Then, in its main page, click Clone from the left side. And click Disk Clone on the right.

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Disk Clone

Please note that the free version SSD cloning software only supports cloning hard drive (contaning operating system) to SSD with the same partition style, clone MBR disk to MBR disk, for example.
 To check partition style between hard drive and target SSD. You could go to disk management, right click the hard disk or the SSD, choose Properties -> Volume tab -> Partition Style, then you will see its partition style, either MBR or GPT.

Step 2. Select the current disk (Disk 0). Then click Next.

Select Source Disk

Step 3. Select the new HDD or SSD (Disk 1) with different block size from the source disk. Then choose Next

Note: The destination disk will be overwritten finally. If you have any important data on it, you must backup them in advance.


Select Destination Disk


Step 4. Confirm everything is right and click Start Clone to clone disk with different size. It's suggested to tick SSD Alignment to accelerate the reading and writting speed if you are cloning HDD to SSD.

Start Clone

If you are cloning a smaller hard drive to a larger one, you need to adjust the partition size of destination disk during the process. If not, the cloned hard drive will not show full capacity.

It has three options, including "Copy without resizing partitions", "Add unused space to all partitions", "Manually adjust partition size". The last two options are supported by AOMEI Backupper Professional, you need to upgrade the freeware before using this feature. 

Add Unused Space

Now, the cloning process may already complete, and you still need to check if it can boot successully. Shutdown your computer completly, swap hard drive and set the cloned drive as the first boot option, then restart to check if all the programs and data are there.

Boot from the cloned SSD

Note: This software also allows you to clone GPT disk to smaller SSD, clone dell hard drive to SSD, clone SSD to larger SSD Samsung, clone Windows 10 to new hard drive, replace laptop HDD with SSD with the same steps above.


Copying drives with different block sizes can be easily done with the help of AOMEI Backupper Standard. Its intuitive interface and simple steps make the disk clone effortless. It is worth mentioning that this software can help you retain the best performance of SSD. And it won’t interrupt your work.

Also, you can only migrate operating system to SSD with its "System Clone" feature in AOMEI Backupper Professional if there is not enough disk space to hold everything on the old drive. You can clone specific partitions with "Partition Clone".