IBM mainframe sales plunge 42% as customers delay purchases

IBM reported fourth-quarter results on Wednesday with revenue of $17.2 billion（約2.8兆円）, gross profit of $9.9 billion（約1.6兆円） (nearly 58% margins), and net earnings of $2.2 billion（約3500億円）—solid absolute numbers that missed Wall Street's expectations so badly that CEO Arvind Krishna took the unusual step of publishing a "letter to investors" last week with preliminary results. That advance warning triggered an immediate 25% stock decline, the company's biggest single-day drop ever, because it flagged severe weakness in IBM's "infrastructure" category and profit margin compression. The culprit became clear on the earnings call: the mainframe business, IBM's traditional cash cow, fell 42% in the quarter. This is a cascading problem because of the unusual leverage CFO Jim Kavanaugh explained: IBM earns $3 in software revenue for every $1 of mainframe hardware sold, meaning a sharp hardware decline directly threatens software revenue and overall profitability. Krishna and Kavanaugh spent the call defending the quarter by framing it as a temporary pause rather than a structural collapse. They explained that "tens" of customers who were scheduled to purchase new mainframes during the quarter postponed their orders—not abandoning mainframes, but reallocating budgets. The reason: component costs for data center equipment and PCs have spiked 15% to 30% due to the AI build-out boom, forcing enterprise buyers to direct cash toward urgent infrastructure upgrades. This echoes warnings from Dell, HP, and Apple about AI-driven component inflation. Krishna said some of those delayed customers have already resumed mainframe purchases in the current quarter and promised the rest will follow once they absorb the cost increases and refresh their systems. "We see no evidence of clients moving off the mainframe," Krishna stated, reassuring the market that the decline is temporary. However, IBM's decision to lower full-year growth forecasts suggests the company expects the headwind to persist through 2024.

IBM's 42% mainframe decline is the immediate symptom of a deeper tension created by the AI data center boom itself. The same component shortages and price pressures that have lifted cloud and data center vendors—driving Dell, HP, and Apple to raise prices—have forced enterprise customers to pause or postpone discretionary spending on legacy systems like mainframes. This represents a temporary budget collision rather than a fundamental shift in demand: mainframe hardware costs hundreds of thousands to millions of dollars per unit, and when customers face a choice between absorbing 15% to 30% cost increases on immediate data center and PC needs versus deferring a major mainframe refresh cycle, the math favors delay. Krishna's confidence that these customers will return rests on the assumption that the AI-driven cost spike is transient and that the unique economics of mainframes—where a single hardware purchase unlocks years of $3 software revenue per $1 hardware—will eventually outweigh short-term budget constraints. However, the company's decision to pre-warn investors and lower full-year guidance suggests IBM does not expect a quick recovery, acknowledging that the mainframe revenue loss will ripple through 2024.