① Licensing concept · Hardware and cost
A new machine can lift software cost while the workload sits still, because capacity based licensing tracks the box. The z16 to z17 move is a software negotiation that happens to involve hardware.
The box changes the bill. Even when the workload does not.
A mainframe hardware refresh is never only a hardware decision, because most mainframe software is licensed on capacity measured in MSU. When the machine changes, the MSU ratings and full capacity figures change with it, and capacity based entitlements can float up even if the workload is flat. IBM announced the z17, built on the Telum II processor, on April 8, 2025, with general availability from June 18, 2025. Every generation brings a per core performance increase, which is good for throughput and a question mark for licensing, because the same work can map to a different MSU figure on the new box.
There is a counterweight. IBM has historically applied a technology dividend, sometimes called a technology transition adjustment, that lowers the MSU rating for the same workload on a newer machine so a like for like move does not raise MLC charges as much as raw capacity would imply. The size and applicability vary by generation and pricing metric, so it offsets some of the refresh but cannot be assumed to cover it. The buyer's job is to pin down the actual MSU mapping and the renewal terms before the order is committed, while leverage still sits on their side of the table.
The levers a machine change pulls, the direction each tends to move cost, and the protection to negotiate. Direction is the common pattern; verify the specific generation move against current data.
| Lever | Typical effect | Protection to negotiate |
|---|---|---|
| MSU rating per workload | Changes with generation | Confirm the technology transition treatment |
| Full capacity of the box | Usually rises with a larger machine | Stay sub-capacity, cap entitlements |
| Capacity based entitlements | Float up without a cap | Cap so they do not track the box |
| Third party product bundles | Ride the new capacity number | Renegotiate caps with each publisher |
| Renewal timing | Often coincides with the refresh | Decouple renewal from the hardware order |
One estate moving from an older box to a larger new one, with identical workload. The rate per MSU is an illustrative placeholder R; actual rates and MSU ratings are product and generation specific and not stated here. The difference is the contract, not the machine.
| Measure | Uncapped contract | Capped contract |
|---|---|---|
| Workload before and after | flat | flat |
| Full capacity of new box (MSU) | 1,400 | 1,400 |
| Entitlement basis after refresh | tracks box | capped at need |
| Capacity billed (MSU) | 1,400 | 900 |
| Software charge basis | 1,400 × R | 900 × R |
| Outcome of the refresh | + cost | flat cost |
Both estates run the same work on the same new machine. The uncapped contract lets entitlements track the box, so a larger machine raises the software charge basis for no extra throughput in production. The capped contract holds entitlements to genuine need, so the refresh delivers the hardware benefit without a software penalty. The machine did not decide the outcome. The contract, negotiated before the order, did.
Without a cap, capacity based entitlements track the new machine's capacity, so a larger box raises the licensing baseline even with flat workload. This is one of the most common sources of an uplift that buyers never planned for.
Broadcom (CA), BMC, and other publishers price on the same capacity figure. A refresh that lifts the capacity number can lift every third party bundle at once, so the negotiation spans every publisher, not just IBM.
Once the hardware order is committed, leverage shifts. The credible option to wait, or to size differently, evaporates, and the renewal lands on the vendor's terms. The window to negotiate is before the box is locked.
Buyers often assume the technology transition adjustment covers the refresh. Its size varies by generation and metric, and on some moves it offsets only part of the change, so it has to be verified for the specific z16 to z17 mapping, not taken on faith.
Negotiate before the order, cap the entitlements, verify the dividend.
Treat a z16 to z17 refresh as a software negotiation with a hardware deadline. Model the post refresh MSU against current SCRT data so you know what the new box actually maps to, and confirm the technology transition treatment for this specific generation move rather than assuming it. Cap capacity based entitlements so they hold at genuine need instead of floating with the machine, and run the same conversation with every third party publisher whose products ride the capacity number. Above all, settle the software terms before the hardware order is committed, while the option to wait or resize still gives you leverage.
The number under all of this is capacity, so read MIPS and MSU explained for how MSU is built and group capacity limits for the capping that holds the peak. If a refresh is prompting a pricing model change, see Tailored Fit Pricing, where the baseline conversation interacts with the new box. When the order is approaching, our mainframe license negotiation and cost optimization teams settle the software terms before the hardware locks them in.
It can, even with flat workload. Capacity based software is licensed in MSU, and a new generation changes ratings and full capacity. Without caps, entitlements and renewals can float up with the box.
IBM announced the Telum II based z17 on April 8, 2025, with general availability from June 18, 2025, and the Spyre Accelerator to follow later that year. Each generation brings a per core performance increase worth checking against the baseline.
The historical pattern of IBM lowering the MSU rating for the same workload on a newer machine, so a like for like move costs less than raw capacity implies. Its size varies by generation and metric, so verify it for the specific move.
Negotiate before the hardware order is committed. Cap capacity entitlements, confirm the technology transition treatment, and model post refresh MSU against current SCRT data. Fix it before the box ships, not at the renewal after.