Thanks, Dion. We finished FY '18 with a strong Q4. Our results demonstrate the consistency of our strategy and focus on creating shareholder value for the long term. We delivered against our objectives with a focus on day-to-day execution while also investing in our strategic growth initiatives across Personal Systems, Printing and 3D to position the company for the future.
For the full year, we grew revenue and operating profit dollars across both Printing and Personal Systems. We also delivered strong earnings per share growth, generated $4.2 billion in free cash flow and returned 83% of that free cash flow to shareholders, above the high end of our long-term range of 50% to 75%.
Now let's look further into the results for the fourth quarter. Starting with the top line, net revenue was $15.4 billion, up 10% or up 9% in constant currency. Just as we've seen throughout the year, our performance remained strong across businesses and geographies. Regionally, in constant currency, Americas grew 6%, EMEA was up 9% and APJ grew 17%. Gross margin was 17.6%, down 0.5 points, primarily resulting from the addition of S-Print. Sequentially, gross margin was down 0.8 points, driven by seasonal business mix and currency.
Non-GAAP operating expenses of $1.6 billion were up 7%. This increase was driven by the addition of S-Print along with the incremental R&D and go-to-market investments to support growth. Non-GAAP net OI&E expense was $54 million for the quarter. We delivered non-GAAP diluted net earnings per share of $0.54, up $0.10 or 23% year-over-year with a diluted share count of approximately 1.6 billion shares.
Non-GAAP diluted net earnings per share excludes amortization of intangible assets of $20 million, acquisition-related charges of $26 million and restructuring and other GAAP-only charges totaling $45 million, offset by nonoperating retirement-related credits of $54 million and related tax impact on all of these items. It also excludes a net gain of $597 million related to tax adjustments. The noncash gain was primarily related to a change in our ability to utilize certain deferred tax assets. As a result, Q4 GAAP diluted net earnings per share was $0.91.
At the segment level, Personal Systems net revenue remained strong, delivering $10.1 billion, up 11%. Results were again broad-based across customer segments, geographies and products, reflecting the strength of our product portfolio, go-to-market and supply chain. By customer segment, Consumer and Commercial revenue were both up 11%. By product category, revenue was up 14% for Notebooks, up 6% for Desktops and up 10% for Workstations.
In calendar quarter 3, our market share was 22.5% as we continued to execute our strategy and focus on profitable growth. Our performance was driven by strong execution as we managed a dynamic market environment and the initial signs of CPU shortages, which we expect will constrain our growth in the first half of 2019.
Personal Systems continued to grow operating profit, up $37 million versus last year. This increase was primarily driven by higher volume and better ASPs, partially offset by higher commodities and logistics costs and the initial impact of tariffs in the U.S. Operating margin was 3.8%, flat year-over-year.
In Printing, revenue was $5.3 billion in the quarter, up 9%. We have made steady progress in the performance of the business and remain focused on managing our core businesses of building for the future across our strategic growth initiatives.
Total hardware units were up 11% with Consumer units up 3% and Commercial units up 85%, including S-Print. We continue to take advantage of opportunities to place NPV positive units when we see them. In calendar quarter 3, overall Print unit share was 42%.
Q4 Supplies revenue of $3.4 billion was up 7%. The Supplies mix of total Print revenue was 64%, down year-over-year and sequentially. We continue to operate below our ceilings for Supplies channel inventory. For the full year, Supplies revenue grew in line with our outlook, inclusive of the acquired S-Print supply stream and installed base which, as we described at SAM, we expect to continue to decline.
Printing operating profit grew $46 million versus last year and operating margin was 16.1%, down 0.5 points year-over-year, up 0.1 points sequentially. The primary drivers of the year-over-year margin decline were the addition of S-Print and the strong unit placements as well as investments in growth and future initiatives, including A3 and 3D Printing, partially offset by favorable currency.
Turning to cash flow and capital allocation. Q4 cash flow from operations was $968 million, and free cash flow was $843 million. For the full year, we delivered free cash flow of $4.2 billion, above our previously provided guidance of at least $3.7 billion.
Q4 free cash flow includes both the timing benefit of higher Personal Systems volume and a better year-end cash conversion cycle of minus 32 days. This was an improvement versus our prior outlook of minus 29 to minus 30 days, driven by lower days of inventory. Sequentially, cash conversion cycle weakened 2 days, in line with typical seasonality with a 3-day decrease in days payable outstanding; a 2-day increase in days sales outstanding, driven by revenue linearity; and a 3-day decrease in days of inventory, largely a result of a decrease in strategic purchases.
We returned $598 million to shareholders through share repurchases and $219 million via cash dividends in Q4. For the full year, we returned $3.5 billion to shareholders through share repurchases and dividends or 83% of free cash flow.
Looking forward to FY '19, keep the following in mind related to our overall financial outlook: Based on recent moves in the U.S. dollar, we are expecting increased headwind from currency compared to the end of September rates we used in the outlook we provided at SAM. Our plans to mitigate previously announced and implemented China-U.S. tariffs are on track. As described at SAM, we expect the headwind to be larger in the short term and reduced throughout the year. We have not considered any impact from unannounced tariffs or any significant demand changes that may result from an increase in geopolitical uncertainties.
Specific to Personal Systems, we expect CPU supply constraints through the first half of 2019. Regarding the overall basket of components and logistics, we expect the cost to improve compared to Q4 levels. This should offset some of the increased currency headwind, assuming the market is not incrementally more competitive.
In Printing, we continue to expect overall Supplies revenue to be flat to slightly up for the full year. And we are including the full year expected impact from the Apogee acquisition. In addition, for the full year, we expect our non-GAAP tax rate, which is based on our long-term non-GAAP financial projection, to be 16% in FY '19.
Taking these considerations into account, we are providing the following outlook: Q1 '19 non-GAAP diluted net earnings per share to be in the range of $0.50 to $0.53, Q1 '19 GAAP diluted net earnings per share to be in the range of $0.46 to $0.49. We are maintaining our full year fiscal 2019 non-GAAP diluted net earnings per share to be in the range of $2.12 to $2.22 and full year fiscal '19 GAAP diluted net earnings per share to be in the range of $2.04 to $2.14, and we expect to return approximately 75% of free cash flow to shareholders through a combination of dividends and share repurchases over the course of the full year.
And now let's open up the call for questions.