Here it is:
Your system supports maximum of 32GB DDR3 RAM with speed of 1600MHz.
Achieve high performance.
Harness Intel® Core™ i5 or Intel® Core™ i7 processor speed, ample storage, high-bandwidth memory and powerful discrete graphics options of the OptiPlex 9010.
• Tackle your toughest jobs with up to 3rd Generation Intel® Core™ i7 processors, featuring large, high-frequency cache for serious multitasking.
• Get the latest productivity tools with Windows 8 Pro.
• Find your balance of technology and performance with hard drive, SSD or hybrid drive options.
• Run multiple programs simultaneously with high-bandwidth DDR3 memory.
• Enjoy outstanding graphics performance with optional NVIDIA® GeForce® graphics (available in Mini-Tower only).
• Speed through your workload with up to 32GB of memory and support for up to 1600MHz.