Our earnings materials are available on our IR website and I encourage you to review these materials. We had a strong operational execution in the second quarter with record AI shipments. Earnings per share increased by 19% to $2.32, marking a Q2 record. Our modernization work continues to enable internal efficiencies driving decoupling of revenue growth and operational expenses which were down 4% while continuing to invest in R&D.
This strong performance resulted in another quarter of robust cash generation and significant capital returns to shareholders. Building on the exceptional demand observed in Q1, we booked $5.6 billion in orders in the second quarter and shipped a record $8.2 billion, resulting in an ending backlog of $11.7 billion. Our five quarter pipeline continued to grow sequentially with double digit growth across enterprise and sovereign opportunities. Our pipeline remains multiples of our backlog enterprise orders and our buyer base grew sequentially in Q2, distributed across various industries such as financial services, healthcare, and manufacturing.
In an environment where speed matters, customers are seeing in real time the value in our ability to deploy large scale clusters quickly and reliably. Our execution, value add through engineering, and ability to Dell design and even Dell manufacture components within our at scale data center solutions drive margin rate improvement within AI. We now have six consecutive quarters of year-over-year P&L growth from a demand perspective. International markets grew, but the April weakness we saw in North America continued.