The short answer
- Choose LTO-10 for a new installation, for petabyte-scale data, or when you want the lowest number of cartridges and slots.
- Choose LTO-9 if you need to keep reading and writing LTO-8 tapes, or you are expanding an existing LTO-8/LTO-9 library.
- Security features are the same: both offer AES-256 encryption, WORM and an offline air gap.
LTO-9 vs LTO-10 specifications
| LTO-10 (40TB) | LTO-10 | LTO-9 | LTO-8 | |
|---|---|---|---|---|
| Native capacity | 40 TB | 30 TB | 18 TB | 12 TB |
| Compressed capacity | 100 TB | 75 TB | 45 TB | 30 TB |
| Compression ratio | 2.5:1 | 2.5:1 | 2.5:1 | 2.5:1 |
| Native transfer rate | 400 MB/s | 400 MB/s | 400 MB/s | 360 MB/s |
| Compressed transfer rate | Up to 1,200 MB/s* | Up to 1,200 MB/s* | 1,000 MB/s | 900 MB/s |
| Native data per hour | 1.44 TB | 1.44 TB | 1.44 TB | 1.30 TB |
| Reads older tapes | None | None | LTO-8 | LTO-7 |
| Writes older tapes | None | None | LTO-8 | LTO-7 |
| New-cartridge optimisation | Not required | Not required | Yes (one-off) | No |
| Media | Strontium-doped BaFe, Aramid base | Strontium-doped BaFe | BaFe | BaFe |
| Encryption | AES-256-GCM | AES-256-GCM | AES-256-GCM | AES-256-GCM |
| WORM / LTFS | Yes / Yes | Yes / Yes | Yes / Yes | Yes / Yes |
| Archive life | Up to 30 years | Up to 30 years | Up to 30 years | Up to 30 years |
*LTO-10 compressed throughput depends on drive interface and data compressibility. The LTO Program quotes up to 1,200MB/s on 32Gb Fibre Channel drives.
Capacity: LTO-10 stores up to 2.2× more
LTO-10’s 30TB cartridge holds 67% more than LTO-9, and the 40TB cartridge holds 122% more, in the same slot. For a 1PB archive, that means:
Fewer cartridges mean fewer library slots and licences, less shelf space offsite, less handling and lower transport costs.
Speed: much the same per drive
Native throughput is 400MB/s for both LTO-9 and LTO-10, so a backup of a given size takes about the same time on a single drive. LTO-10 does remove LTO-9’s first-load media optimisation step, so brand-new cartridges are ready to write straight away. If you need shorter backup windows, add drives. That works for either generation.
Compatibility: the deciding factor
This is where the two generations really differ:
LTO-9
Reads and writes LTO-8 cartridges. You can add LTO-9 drives to an LTO-8 library, keep using the LTO-8 media you have, and restore your LTO-8 archive without migrating it.
LTO-10
Reads and writes only LTO-10. To restore older tapes you need to keep an LTO-9 (or older) drive in service, or migrate the archive onto LTO-10 media.
Which should you choose?
Choose LTO-9 if…
- You use LTO-8 today and want to keep reading and writing those tapes
- You are adding drives or media to an existing LTO-8/LTO-9 library
- Your data grows by less than about 50TB a year
- You want to migrate gradually, without replacing all your media at once
- You want the lowest drive cost today
Choose LTO-10 if…
- You are building new backup or archive infrastructure
- You hold petabyte-scale data: video, research, CCTV, AI or cloud logs
- You want the longest runway from your investment
- Cutting cartridge count, slots and handling is a priority
- You can cover the higher drive cost in exchange for lower cost per TB over time
Security: no difference
Both generations give you the same enterprise-grade protection:
- AES-256 hardware encryption at full speed. LTO-10 adds post-quantum-ready key exchange support.
- WORM cartridges for tamper-proof archives
- Air-gapped ransomware protection once cartridges are offline
- Support for compliance with GDPR, financial services and healthcare retention rules
Choose on capacity, compatibility and budget, not security. For more detail, see the LTO-10 specifications and LTO-9 specifications.
A common approach: run both
Many of our customers put LTO-10 drives into a partition for all new backups and archives, and keep one or two LTO-9 drives in another partition to restore older LTO-8 and LTO-9 media. Over time, the archive is migrated onto LTO-10 and the older drives are retired. Most modern libraries support this.
Send us your data volumes, growth rate and current hardware, and we will recommend LTO-9, LTO-10 or a mix.