Manufacturer

IBM TS4500 Tape Library (TS3500 Successor)

IBM's frame-scale enterprise tape library, the next-generation replacement for the TS3500/3584 family, holding up to 13 PB native (39 PB compressed) per frame with LTO 9.

IBM's frame-scale enterprise tape library, the next-generation replacement for the TS3500/3584 family, holding up to 13 PB native (39 PB compressed) per frame with LTO 9.

Status
Current IBM product; successor to the TS3500 (machine type 3584), not a rename
Form Factor
Frame-based, single L-frame expandable to 17 additional frames
Capacity
Up to 5.5 PB in a single 10-square-foot frame at earlier LTO generations; up to 13 PB native (39 PB compressed at 2.5:1) with LTO 9
Scalability
Over 23,000 cartridge slots across a full multi-frame configuration
Drive Support
LTO Ultrium drives plus IBM's own enterprise drives: TS1160, TS1155, TS1150, TS1140
Compatibility Note
High-density (HD) generation 1 frames from an existing TS3500 can be redeployed into a TS4500

The TS4500 is IBM's current frame-scale enterprise tape library, and the direct successor to the TS3500 (IBM machine type 3584) that many older AS400/IBM i and mainframe-adjacent shops still have in the data center. It is not simply a rebadge: the TS4500 is a newer platform with a smaller physical footprint per petabyte, and IBM explicitly supports redeploying existing TS3500 high-density (HD) generation 1 frames into a TS4500 upgrade rather than requiring a full rip-and-replace.

A single 10-square-foot frame holds up to 5.5 PB using earlier LTO generations, or up to 13 PB native (39 PB at 2.5:1 compression) with LTO 9 media. The library scales from one L-frame up to 17 additional expansion frames, with a combined capacity over 23,000 cartridge slots, which is the range where TS4500 stops being a mid-range decision and starts being a data-center architecture decision. Beyond Ultrium LTO drives, the TS4500 also supports IBM's own enterprise tape drives (TS1160/1155/1150/1140), used in mainframe and high-throughput enterprise environments more than typical AS400/IBM i shops.

Most AS400/IBM i environments searching for a TS3500 replacement are not at TS4500 scale and land on the mid-range TS4300 instead; the TS4500 is the right comparison point specifically when the existing TS3500 install already spans multiple frames or thousands of cartridges.