Today is the day after Thanksgiving – otherwise known as Black Friday. A friend found a good deal on a Seagate 3TB external hard drive with USB 3.0 speeds. Since he did not have a USB 3.0 port on his computer, he wanted to move his files via SATA, but when he removed it from the external enclosure and connected the hard drive straight into the computer, it only showed 349GB (or sometimes 746GB if it is a WD hard drive).
Here’s a quick explanation of what is going on and how to format the drive so that it is usable with 3TB or roughly 2.7TB due to allocation of drive space. We’ll go through the difference between MBR and GPT formats, discuss how it originally recognizes with USB and not SATA, and finally how to format the drive in Windows.
MBR vs. GPT
First, hard drives are typically formatted in MBR (Master Boot Record) or GPT (GUID Partition Table). When you install your operating system, like Windows XP or Windows 7, the drive needs to be formatted as MBR because that drive needs to be bootable in order to load an operating system. The MBR system will allow you to create a partition of 2TB in size, while the GPT system will allow you to go beyond the 2TB limit. So in theory, if you have an 8TB hard drive, you can only make four 2TB partitions with MBR, whereas with GPT, you can make one 8TB partition or a hundred 80GB partitions.
USB vs. SATA
When you used your external hard drive, the 3TB hard drive was recognized without any problems, but when you installed it into your computer, hard drive size detection became an issue. One possible explanation is that the device is originally intended to be operated as an USB device, so the controller board is designed to get past that 2TB limit, so without the additional hardware, you didn’t see the entire 3TB as one volume.
Formatting the 3TB Hard Drive in Windows
*** NOTE: Please back up information you want to keep before formatting drive. ***
1. Go to “My Computer,” right-click on it, and select “Manage” from the menu.
2. Look for your drive at the bottom of the screen (Disk 1.. Disk 2… Disk 3.. etc..)
3. Right-click on the partition of selected drive and Delete Volume… to delete the partition.
4. The drive should show up as “unallocated partition” and may show up as two separate partitions. (One partition will be 2048GB and the other as 746GB or something like that)
5. On the left, click on the Disk # part, and click on “Convert to GPT Disk”.
6. Then proceed to format the drive as NTFS by right clicking on the partition and “Create New Simple Volume…” and go through the wizard to create a new simple volume, which will ultimately end with the options to format your drive as NTFS.
7. Open My Computer to see if you drive shows up in Explorer.
8. If it doesn’t show up, go back to Disk Management and see if the drive has been made into an active partition and also check to see if it has been assigned a drive letter. All of this can be done by right-click on the partition of the drive.
This technique should help you utilize the maximum capacity of your 3TB hard drive. If you have any comments or suggestions, please feel free to let me know!
Added October 11, 2013
There are many of people who are encountering a problem where their 3TB hard drive can only format 2TB, and no other partitions are seen to be deleted or altered. This could be due to several factors, but the following steps should help you recover the missing partition(s) beyond the 2TB, and hopefully allow your hard drive to return to its original unallocated state.
We need to wipe the drive clean and restore it. After plugging in the hard drive, please do the following:
1. Start > right-click on Computer > go to Manage…
2. Choose Disk Management on the left hand side of the menu and check what number the drive is detected as in your list of disks.
3. The hard drive should appear in a list in the lower part of the window.
4. Remember the disk number of your hard drive. (Disk 0, 1, 2, etc…) It’s bolded next to the partitions of the drive.
5. You can now now close this window and we will begin clearing the drive.
**All data on the hard drive will be wiped from here on. Please back up important data.**
1. Start > type in “cmd” in the search box below All Programs and press Enter.
2. A black window opens up, this is your DOS command line.
3. Type “diskpart” and press Enter to launch the Disk Partition window.
4. Type “list disk” and press Enter to show the all the hard drives in the computer.
5. Type “select disk #” where # is the drive disk number determined in Disk Management, and press Enter. (i.e. “select disk 2” and pressing enter will tell the program to select the hard drive you would like to wipe clean.
6. Type “clean” to restore the hard drive by writing zeroes for all sectors.
7. Once finished, go back to Disk Management and check to make sure that hard drive partition is now “unallocated”.
8. Initialize Disk if the drive isn’t initialized already, and follow the above procedures to convert the disk to a GPT disk and proceed with formatting the drive for use.