DELL OptiPlex 990 USFF desktop PC Intel Quad-Core i5 2.9-3.30GHz 4GB DDR3 1TB HDD

Compact desktop for office tasks

The Dell OptiPlex 990 USFF is a new ultra-small-form-factor PC built around a 2nd-generation Intel quad-core i5 processor that runs between 2.9 GHz and 3.30 GHz. It ships with 4 GB of DDR3 memory, a 1 TB 3.5" SATA hard drive and a 16X DVD±RW drive. Windows 10 Professional 64-bit is pre-installed with a Certificate of Authenticity, and a USB keyboard plus a USB Wi-Fi adapter are included so the system is ready for general business or home-office use right out of the box.

Sustained workload behaviour

Under continuous load the quad-core CPU can maintain clocks up to 3.30 GHz while the integrated Intel HD Graphics 2500 handles basic display output. The 1 TB mechanical drive delivers steady sequential throughput for document storage and application loading, and the Gigabit Ethernet port provides a stable wired network link for long file transfers or remote sessions. The compact chassis relies on a small internal fan, so extended heavy compute tasks will cause the system to throttle once thermal limits are reached.

Installation notes and common issues

The USFF case opens with a tool-less latch, giving direct access to the two 240-pin DDR3 slots and the single 3.5" drive bay. Adding more memory or swapping the hard drive is straightforward, but the low-profile design prevents full-height expansion cards and leaves no room for a second 3.5" drive. The supplied USB Wi-Fi adapter occupies one port and may need driver updates on fresh Windows installs, while the slim optical drive uses a proprietary slimline SATA connector that limits replacement options.