Operating System, Processor and Memory

• Each Dell Precision T7500 and Dell OptiPlex 980 ArcGIS runs on Microsoft's Windows 7 or Windows Vista operating system; a Windows XP downgrade for the OptiPlex desktop is available. While the T7500 has the server- and workstation-oriented Intel Xeon processor with up to six cores, the 980 has less powerful but more processor choices with dual- and quad-core entries of the mid-level consumer-oriented Pentium and flagship Core brands. The T7500 can contain up to 192 GB of system memory, outstripping the OptiPlex computer's maximum expandability of 16 GB.
  
  

Disk Drives and Multimedia

• The Dell Precision T7500 workstation can come with up to 10,000 GB, or 10 TB, of hard drive storage. The OptiPlex 980 ArcGIS's maximum data storage is only 5/100ths of the T7500's, with 500 GB. Also, Dell includes a USB floppy drive on the workstation. Both desktops, however, have an optical drive that can accommodate CDs, DVDs and/or Blu-ray discs, as well as a flash memory card slot. Regarding video and graphics capabilities, the T7500 has 16 choices of discrete graphics processing units from GPU manufacturer Nvidia and semiconductor company Advanced Micro Devices. The OptiPlex 980 usually has the less powerful, motherboard-integrated Intel Graphics Media Accelerator, although there are four other GPU choices -- discrete cards or integrated -- from AMD and Nvidia.
  
  

Networking and Connectors

• Each Dell Precision T7500 and Dell OptiPlex 980 ArcGIS has an Ethernet controller for wired networking that provides up to 1,000 megabits, or one gigabit, per second in data transfer speed. Added on the OptiPlex desktop is a Peripheral Component Interconnect Express-connected card for wireless networking; it adheres to the Institute of Electronics and Electrical Engineers' 802.11n standard. Apart from the RJ-45 jack for the Ethernet, the connectors on the desktops include a Video Graphics Array port for the computer display, headphone and microphone jacks, and an external Serial Advanced Technology Attachment interface for connecting an external hard drive. Dell adds two FireWire ports, serial and parallel ports, and two PS/2 connectors for the keyboard and mouse on the Precision; and a DisplayPort for digital audio/video content on the OptiPlex. The T7500 offers 11 USB ports, while the OptiPlex can offer up to 10.
  
  

Models and Sizes

• The Dell Precision T7500 is only available as a traditional desktop tower, with physical dimensions consisting of a 8.5-inch width, 22.26-inch height and 22.3-inch depth. The OptiPlex 980 ArcGIS offers three form factors, in descending order of size -- the mini-tower; the desktop tower, which is what the T7500 uses; and the small form factor. The MT measures 7.33-by-16.06-by-19.96 inches; the DT measures 4.2-by-15.61-by-13.7 inches, making it smaller than the T7500; and the SFF measures 3.35-by-11.4-by-12.74 inches.