Nowadays, terabyte hard drives are becoming more popular, but conventional 32-bit Windows systems cannot fully recognize 2.1TB or more. This article will decrypt the original. With the big price cuts in memory, many friends know that 32-bit Windows systems can only recognize 3.25GB of memory. However, you may not know that the 32-bit Windows system can only recognize the capacity of the hard disk below 2.1TB. Why is this restriction happening, and how can we lift this restriction? The origin of the restriction —— LBA addressing mode limits hard disk capacity Hard disk capacity and Windows entanglement is not only 2.1TB. In fact, since 1980, there have been at least ten hard disk capacity limitations in the storage industry in the past 30 years. The most familiar ones are the 528MB, 2.1GB, 8.4GB, and 137GB hard drive capacity limits. Of course, these limitations have been resolved, but due to the limitations of LBA addressing, 2.1TB has once again become a new threshold for Windows and hard drive capacity. LBA refers to Ligical Block Address, 48bit is now the mainstream addressing mode, the number of sectors that theoretically support addressing is 281474976710655 (2 to the 48th power), and the supported hard disk capacity reaches 281474976710655 ×. ; 512 = 144115188075855872 bytes (LBA defaults to 512 bytes per sector), roughly equivalent to 144PB = 144000GB capacity, the hard disk capacity structure shown in Figure 1. Therefore, only from the 48-bit addressing mode, the system can recognize more than 2.1TB of capacity, but now the mainstream Windows system is 32-bit, so the addressing of the hard disk is naturally only 32-bit, which supports the largest addressed fan. The number of zones is 2 to the 32nd power, which is 4294967296. Therefore, the maximum supported capacity is 4294967296× 512=2199023255552Byte, and the converted capacity is about 2.199TB. This is the origin of the 2.1TB capacity limit. On the other hand, the 32-bit addressing mode limitation still exists in the MBR partition mode currently used by the hard disk, which is also a key factor limiting the capacity of the hard disk. The MBR can support up to four primary partitions or a combination of three primary partitions and one extended partition. This scheme uses 4 bytes to store the total number of sectors in the partition. The maximum number of 32-th power sectors can be represented by 512 bytes per sector, so that the maximum capacity of each partition cannot exceed 2TB. When the disk capacity exceeds 2TB, the starting position of the partition cannot be represented, and of course, the partition cannot be performed. For example, if you connect a 3TB hard disk in a 32-bit Windows 7 system, if you use the traditional partitioning tool, you will have up to 746.52GB of hard disk capacity (see Figure 2). Restricted resolution —— Let the system recognize the capacity after 2.1TB From the above description, we know that the 2.1TB capacity limit is mainly caused by 32-bit addressing, one is the limitation of the 32-bit operating system itself, and the other is Traditional MBR partitions use 32-bit addressing limitations. Therefore, in order for the system to fully recognize the capacity after 2.1TB, it is necessary to solve the above two limitations. 1.32-bit operating system limitations —— Dressing 64-bit operating system Windows supports the number of sectors addressed = 2 to the number of addressing bits, so as long as the number of addressing is increased, the number of supported sectors can be increased. Since 64-bit systems support 64-bit addressing numbers (theoretical value is equal to 2 to the 64th power), multiplying the number of sectors makes it easy to break the 2.1TB limit. To fully use all the capacity of a large hard drive, you must first use a 64-bit operating system. 2. MBR partition restrictions —— Using GPT partitions Even with 64-bit systems, due to MBR partitioning restrictions, we still can't use more than 2.1TB hard drives, and we need to use GPT partition format to fully identify. Tip: What is GPT Partition GPT (GUID Partition Table) was introduced as part of the Extensible Firmware Interface (EFI) program. GPT provides a more flexible disk partitioning mechanism than the Master Boot Record (MBR) partitioning scheme commonly used in PCs. GPT disks can achieve huge capacity. The number of partitions on GPT disks is not limited by temporary schemes (such as the container partition defined by MBR Extended Boot Record). In theory, there can be countless GPT partitions (currently Windows supports up to 128 GPT partitions) . GPT has no restrictions on the number of partitions, and it uses a 64-bit integer to represent the sector number, so theoretically allows users to partition using up to 18 EB capacity (1 EB = 1 million TB). Using GPT partitions can avoid the limitations of MBR partitions. Now mainstream Windows 7 systems can perfectly support GPT partitions (see Table 1 for common operating system support for GPT partitions). The right medicine, 32/64-bit system is perfect for using large hard disk 1. Just for data storage. We know from the above table that 32-bit Windows 7 supports GPT partition, but the capacity after 2.1TB cannot be recognized due to the limitation of addressing mode. . It would be unrealistic to replace a 64-bit system just for a large hard drive. So in order to allow 32-bit systems to use 3TB hard drives, motherboard makers Asus, Seagate, and Gigabyte have launched cracking solutions. Hard drive maker Seagate has also introduced similar patches that allow 32-bit Win7 to use unrecognized capacity (make it virtual) For the disk), let's take the Gigabyte Unlock software as an example. After downloading the software from GIGABYTE's official website, after installing Unlock, he will automatically detect the 3TB hard disk connected to the current system. Click “Create” to automatically simulate the unrecognizable space of 74.52GB as a virtual disk. After successful creation, It can be recognized and formatted in disk management (see Figure 3). 2. For system partitioning From the above table, we know that 32-bit systems do not support booting from GPT partitions. Therefore, if you want to use 3TB hard disk as the system disk, we must use 64-bit system + GPT partition, and the motherboard must support EFI/UEFl boot. (Most of the motherboards released in the past two years are mostly supported). To determine whether your motherboard supports EFI/UEFl startup, just enter the BIOS boot sequence setting menu when you start the computer to see if there is a startup item under UEFl startup (see Figure 4). After confirming that the motherboard supports EFI/UEFl booting, if you want to install Win7 on a 3TB hard disk, we can use the boot USB flash drive (the traditional way to boot Win7 from CD-ROM does not support installation to GPT hard disk). Step 1: Prepare the 64-bit Win7 installation file and a USB flash drive of 4GB or more, format the USB flash drive into FAT32 format (must be, otherwise it will not start), and then copy the Win7 installation files to the USB flash drive. Step 2: Go to any of the 64-bit Win7 computers and copy the "C:\\Windows\\Boot\\EFI\\bootmgfw.efi” file to the U disk"\\efi\\boot” subdirectory and Renamed "bootx64.efi". Step 3: Restart and set UEFI to the first boot mode in the BIOS. After successful booting, plan the partition according to the installation wizard (the wizard will automatically create a GPT type volume) to complete the installation. This installation of Win7 uses the GPT partition, and can perfectly recognize the capacity after 2.1TB. This article comes from [System Home] www.xp85.com