Gianluca Romano
Analyst · Bank of America
Thank you, Dave. Seagate continued to execute well and navigate a complex business environment to deliver a solid financial performance aligned with our expectations. In the December quarter, we grew revenue to $3.12 billion, up 19% year-over-year. Delivered non-GAAP operating margin of nearly 20%, up 520 basis points year-over-year and increased non-GAAP EPS to $2.41, up 87% year-over-year.
In our HDD drive business, we achieved the fifth consecutive quarter of record capacity shipments, totaling 163 exabytes, up 3% sequentially and up 26% year-on-year. Ongoing cloud demand for our nearline products supported mass capacity revenue of $2 billion, up 1% sequentially and up 25% compared with the prior year period. Shipments into the mass capacity market totaled 137 exabytes, up 4% sequentially and 41% year-over-year.
Nearline remains our fastest growing product segment with revenue outpacing the broader mass capacity business. In the December quarter, we increased shipment to 111 exabytes, up 4% sequentially and 56% year-on-year, supported by the ongoing cloud adoption of 18-terabyte drives as well as healthy demand for mid-capacity products from enterprise and OEM customers.
Our 20-terabyte product family is growing strong customer interest, and we are continuing to scale 18 terabyte shipments while also preparing for an anticipated steep 20-terabyte ramp in the coming quarters to support demand.
Sales into the VIA markets remained healthy in the December quarter, following 2 quarters of rapid growth and near record revenue in September. We project a seasonal slowdown in the VIA market during the March quarter, but expect revenue to remain up on a year-over-year basis.
Within the legacy market, revenue came in at $775 million, down 7% sequentially and 15% year-over-year. Seasonal demand for consumer drives partially offset weaker-than-anticipated PC sales due in part to ongoing PC component shortages and lower mission-clinical sales. As we discussed last quarter, component shortages are also impacting sales in our system business as customers delay some ordered product deals due to constrained supply of nondrive components.
Despite these headwinds, non-HDD revenue increased 17% sequentially and 48% year-over-year to a record $294 million, boosted by strong SSD demand. While we continue to face near-term supply challenges for both the system and SSD businesses, we remain confident in growing the non-HDD business in fiscal 2022, particularly for our system solution, where we see ongoing demand and continue to capture new customer logos.
Looking at our operational performance. Non-GAAP gross profit in the December quarter was $958 million. Our corresponding non-GAAP gross margin was 30.7%, down 30 basis points sequentially, but up nearly 400 basis points year-over-year. The ongoing transition to both higher capacity drives and cost-optimized products mostly offset higher freight and logistic costs and the less favorable product mix with a record non-HDD sales. Notably, HDD gross margin remain in the upper half of our long-term target range of 30% to 33%, flat with the prior quarter.
We maintained relatively flat non-GAAP operating expenses at $337 million, lower than expected, reflecting our disciplined expense management and the timing of certain spending. We expect OpEx to be somewhat higher in the March quarter due to an increased R&D expenses and business travel. Our resulting non-GAAP operating income was $621 million, down 1% sequentially and up 61% year-on-year. Non-GAAP operating margin remained relatively flat with the prior quarter at 19.9% and at the top end of our long-term target range of 15% to 20% of revenue.
Based on diluted share count of approximately 225 million shares, non-GAAP EPS for the December quarter was $2.41, which is $0.06 above our guidance midpoint. We increased inventory by approximately $100 million with days inventory outstanding of 54 days to support the upcoming 20-terabyte product trend.
Capital expenditures were $95 million for the quarter, down 19% sequentially. For fiscal '22, we continue to forecast CapEx at the low end of our target range of 4% to 6% of revenue, which is sufficient to support our future product road map while maintaining alignment between near-term supply and demand. Free cash flow generation increased to $426 million, up 12% quarter-over-quarter and 36% year-over-year.
We delivered strong performance in the December quarter and expect to improve free cash flow generation through the fiscal year, enabling us to continue to fund our strong capital return program. In the December quarter, we used $151 million for the quarterly dividend and $471 million to repurchase 5.1 million ordinary shares, exiting the quarter with 219 million shares outstanding and approximately $3.3 billion remaining in our authorization. We ended the December quarter with cash and cash equivalents of $1.5 billion. And total liquidity was approximately $3.3 billion, including our revolving credit facility.
Adjusted EBITDA increased to $723 million in the quarter, our highest level in 7 years, and was $2.6 billion for the 12-month period ending in December. Total debt balance at the end of the quarter was $5.9 billion, and as we previously reported, we plan to repay $120 million in debt coming due in March.
In summary, we delivered solid financial performance, maintaining our focus on driving profitability and free cash flow generation while navigating a dynamic business environment.
Looking ahead to the March quarter, we expect a continuation of the healthy demand environment in the nearline market with anticipated seasonal decline in VIA and the legacy markets. As Dave noted, we are mindful of the ongoing impact related to corporate dynamics and will continue to manage through supply chain constraints and other inflationary pressures that we expect to persist through at least the fiscal year.
We expect March quarter revenue to be in the range of $2.9 billion, plus or minus $150 million. We expect our operating margin to be impacted by COVID-related pressure, what I just discussed over the near term. However, we believe the structural changes in the industry combined with Seagate disciplined execution will support a higher operating margin over time.
As a result, we are raising our long-term target non-GAAP operating margin range to 18% to 22% of revenue compared with our prior range of 15% to 20% of revenue. With that in mind, we expect our March quarter non-GAAP operating margin to be at the lower end of our revised long-term range of 18% to 22% of revenue. And finally, we expect non-GAAP EPS to be in the range of $2, plus or minus $0.20.
Looking further ahead, ongoing demand for mass capacity storage, combined with our strong product pipeline, give us confidence to further raise our fiscal year 2022 revenue growth to be between 12% and 14%, up from our prior outlook in the low double-digit range.
I will now turn the call back to Dave for final comments.