Cixert Posted April 9 Posted April 9 (edited) I have checked and verified the maximum size limits for FAT32, exFAT, and NTFS partitions based on the cluster size. Physical tests were performed using MiniTool Partition Wizard 10.3 on both Windows XP and Windows 10. Some tests have also been performed using Eassos Disk Genius. The hard drives used were Seagate 5 Tb / 6 Tb / 8 Tb and WD 10 Tb. In FAT 32, the calculation is real. In exFAT, I was able to simulate limits of 256 TiB. In NTFS, the calculation is real up to 10 Tb. MAXIMUM LIMITS BY FILE SYSTEM FAT32 File System Maximum FAT32 partition size in MBR --> 8 TiB Maximum FAT32 cluster size in MBR --> 512 KiB Maximum FAT32 partition size in GPT --> 2 TiB Maximum FAT32 cluster size in GPT --> 64 KiB exFAT File System Maximum exFAT partition size --> 256 TiB Maximum exFAT cluster size --> 32768 KiB NTFS File System Maximum NTFS partition size --> 255.99 TiB Maximum NTFS cluster size --> 512 KiB MAXIMUM LIMITS BY PARTITIONING SCHEME MBR Partitioning Scheme* Maximum MBR size on hard disk with 512 byte logical sectors --> 1.99 TiB Maximum MBR size on hard disk with 4096 byte logical sectors --> 15.99 TiB *The limits for the maximum MBR size with logical sector 512 bytes and logical sector 4096 bytes is this real calculation: 1.9999999995343387126922607421875 TiB 15.9999999962747097015380859375 TiB GPT Partitioning Scheme Maximum GPT size on hard disk with 512 byte logical sectors --> 8 ZiB Maximum GPT size on hard disk with 4096 byte logical sectors --> 65536 ZiB 2^64 sectors × 512 bytes = 8 ZiB 2^64 sectors × 4096 bytes = 65536 ZiB *The actual GPT limit is determined by the real limit of file systems which is much lower. MAXIMUM LIMITS BY CLUSTER SIZE FAT32 Partition Limit Cluster 4 KiB = 0.29 TiB / 300.99 GiB / 308223.99 MiB Cluster 8 KiB = 0.59 TiB / 601.99 GiB / 616447.99 MiB Cluster 16 KiB = 1.17 TiB / 1203.99 GiB / 1232895.99 MiB* Cluster 32 KiB = 2.35 TiB / 2407.99 GiB / 2465791.99 MiB Cluster 64 KiB = 4.70 TiB / 4815.99 GiB / 4931583.99 MiB Cluster 128 KiB = 8.00 TiB / 8192.00 GiB / 8388607,50 MiB Cluster 128 KiB = 9.40 TiB / 9631.99 GiB / 9863157.76 MiB Cluster 256 KiB = 18.81 TiB / 19263.99 GiB / 19726325.76 MiB (FAT32 real limit 8 TiB in MBR and 2 TiB in GPT) *Just I exceeds only 3.4 GiB the limit for cluster 16 KiB and problems arose. exFAT Partition Limits Cluster 0.5 KiB = 0.12 TiB / 129.00 GiB / 132104.05 MiB Cluster 1 KiB = 0.25 TiB / 257.00 GiB / 263172.00 MiB Cluster 2 KiB = 0.50 TiB / 513.00 GiB / 525313.97 MiB Cluster 4 KiB = 1.00 TiB / 1025.00 GiB / 1049600.95 MiB Cluster 8 KiB = 2.00 TiB / 2049.00 GiB / 2098176.40 MiB Cluster 16 KiB = 4.00 TiB / 4097.00 GiB / 4195328.06 MiB Cluster 32 KiB = 8.00 TiB / 8192.99 GiB / 8389631.74 MiB Cluster 64 KiB = 16.00 TiB / 16384.99 GiB / 16778239.30 MiB Cluster 128 KiB = 32.00 TiB / 32768.99 GiB / 33555454.52 MiB Cluster 256 KiB = 64.00 TiB / 65536.99 GiB / 67109885.01 MiB Cluster 512 KiB = 128.00 TiB / 131072.00 GiB / 134218746.00 MiB Cluster 1024 KiB = 256.00 TiB / 262144.00 GiB / 268435456.00 MiB ...and so on to cluster 32768 KiB (32 MiB) = 8192 TiB (exFAT real limit 256 TiB) NTFS Partition Limits* Cluster 0.5 KiB = 1.99 TiB / 2047.99 GiB / 2097151.99 MiB Cluster 1 KiB = 3.99 TiB / 4095.99 GiB / 4194303.99 MiB Cluster 2 KiB = 7.99 TiB / 8191.99 GiB / 8388607.99 MiB Cluster 4 KiB = 15.99 TiB / 16384.99 GiB / 16777215.99 MiB Cluster 8 KiB = 31.99 TiB / 32767.99 GiB / 33554431.99 MiB Cluster 16 KiB = 63.99 TiB / 65535.99 GiB / 67108863.98 MiB Cluster 32 KiB = 127.99 TiB / 131071.99 GiB / 134217727.96 MiB Cluster 64 KiB = 255.99 TiB / 262143.99 GiB / 268435455.93 MiB Cluster 128 KiB = 511.99 TiB / 524287.99 GiB / 536870911.87 MiB Cluster 256 KiB = 1023.99 TiB / 1048575.99 GiB / 1073741823.75 MiB ...and so on to cluster 32768 KiB (32 MiB) = 131040.00 TiB (NTFS real limit 255,99 TiB) *Values from cluster 4/8/16/32/64 have been calculated by the previous amounts and I have not verified their correct operation. I think the calculation is 2^32 -1 cluster. The NTFS file system is limited to 32 bits, so the above limits cannot be exceeded under any circumstances. https://learn.microsoft.com/es-es/windows-server/storage/file-server/ntfs-overview In theory, the difference between MBR and GPT is that GPT is capable of redirecting 64 bytes physical sectors. Therefore, with GPT, is it possible to exceed 2 TiB on a hard disk with 512 bytes physical sectors by formatting with a 4 KiB cluster size, and exceed 16 TiB on a disk with 4096 bytes physical sectors by formatting with a 8 KiB cluster size?* *I haven't verified this last point. Let's see if a user with disks larger than 16 TB can confirm if partitions larger than 15.99 TiB are possible. Edited 3 hours ago by Cixert Maximum NTFS cluster size --> 512 KiB (not 64 KiB) Maximum exFAT cluster size --> 32768 KiB (not 1024 KiB)
j7n Posted April 12 Posted April 12 On 4/9/2025 at 10:07 AM, Cixert said: Maximum hard disk size w2000-XP-2003 with 512-byte logical sectors --> 1.99 TiB No such limit on Windows 2003 itself. May be limited by the controller driver. Windows 2003 officially supports GPT and works with at least 4 TB disks. You can browse an upartitioned disk past the 2 TB mark, for example, in WinHex.
Cixert Posted April 15 Author Posted April 15 (edited) On 4/12/2025 at 4:28 PM, j7n said: No such limit on Windows 2003 itself. May be limited by the controller driver. Windows 2003 officially supports GPT and works with at least 4 TB disks. You can browse an upartitioned disk past the 2 TB mark, for example, in WinHex. Yes, you're right. I should have said that those were the MBR limits and not w2000-XP-w2003. It is already corrected. Thank you Edited April 15 by Cixert 1
Cixert Posted 5 hours ago Author Posted 5 hours ago (edited) On 4/9/2025 at 9:07 AM, Cixert said: The NTFS file system is limited to 32 bits, so the above limits cannot be exceeded under any circumstances. https://learn.microsoft.com/es-es/windows-server/storage/file-server/ntfs-overview In theory, the difference between MBR and GPT is that GPT is capable of redirecting 64 bytes physical sectors. Therefore, with GPT, is it possible to exceed 2 TiB on a hard disk with 512 bytes physical sectors by formatting with a 4 KiB cluster size, and exceed 16 TiB on a disk with 4096 bytes physical sectors by formatting with a 8 KiB cluster size?* *I haven't verified this last point. Let's see if a user with disks larger than 16 TB can confirm if partitions larger than 15.99 TiB are possible. According to what a user with hard disks larger than 16 Tb told me in the following Spanish forum... https://foro.elhacker.net/hardware/tamano_limite_de_particiones_fat32_exfat_y_ntfs-t523346.0.html;msg2283776#msg2283776 In GPT, the partition size limit depends on the cluster size, regardless of whether the logical/physical sector size is 512 bytes or 4096 bytes. At least up to 8 ZiB (2^64 sectors×512 bytes=8 ZiB). Therefore, the 2 TiB limit would not be conditioned by a physical sector size of 512 bytes, although manufacturers may find it more convenient to create 4096 byte sectors to reduce the physical volume of the disk. I'm updating the first post with this information. Edited 4 hours ago by Cixert
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