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 up to 10 Tb. 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 --> 16 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 Theoretical limit: 2^28 -11 cluster Macrorit Partition Expert limit: 2^26 cluster True limit: 78.8~ millons clusters 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 Limit any cluster MiniTool Cluster 128 KiB = 8.00 TiB / 8192.00 GiB / 8388608.00 MiB Limit cluster 128 KiB Macrorit Cluster 128 KiB = 9.40 TiB / 9631.99 GiB / 9863157.76 MiB Limit cluster 128 KiB supposed true Cluster 256 KiB = 16.00 TiB / 16384.00 GiB / 16777216.00 MiB Limit Wikipedia, theoretical maximum Cluster 256 KiB = 18.81 TiB / 19263.99 GiB / 19726325.76 MiB Limit 78.8~ millons, not checked (FAT32 real limit 16 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 Theoretical limit: 2^32 -1 cluster True limit: 2^28~ clusters (little more) 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* Theoretical limit: 2^32 -1 cluster True limit: 2^32 -1 cluster 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 56 minutes ago by Cixert Maximum NTFS cluster size --> 512 KiB (not 64 KiB) Maximum exFAT cluster size --> 32768 KiB (not 1024 KiB) Maximum FAT32 size 16 TiB (not 8 TiB)
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 April 23 Author Posted April 23 (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 April 23 by Cixert
Cixert Posted 2 hours ago Author Posted 2 hours ago (edited) The limits I've outlined are the practical limits where no data corruption exists in my tests, although the theoretical cluster limits may be different, I don't know the exact cause: Theoretical NTFS: 2^32 -1 cluster True NTFS: 2^32 -1 cluster Theoretical exFAT: 2^32 -1 cluster True exFAT: 2^28 clusters (little more) Theoretical FAT32: 2^28 -11 clusters True FAT32: 78.8~ million clusters On FAT32, I couldn't get past the 8 TiB partition limit, but I finally managed to do so with Macrorit Partition Expert. With this you can at least up to 16 TiB in FAT32, the real limit of FAT32 partitions according to Wikipedia. However, I can't run tests above 8 TiB to verify the true limits, as Macrorit limits FAT32 partitions to 2^26 clusters. There's some extraordinary news! Microsoft has increased the official FAT32 partition limit from 32 GiB to 2 TiB in the latest version of Windows. I haven't tested this, so I don't know what cluster size it assigns. Edited 29 minutes ago by Cixert
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