Dell OptiPlex 990 (Early 2011) - Manual (Page 101)

Power Wattage Maximum
Heat
Dissipation
Voltage
Mini-Tower 265 W 1390 BTU/hr 100 VAC to 240 VAC, 50 Hz to 60 Hz, 5.0 A
Desktop 250 W 1312 BTU/hr 100 VAC to 240 VAC, 50 Hz to 60 Hz, 4.4 A
Small Form
Factor 240 W 1259 BTU/hr 100 VAC to 240 VAC, 50 Hz to 60 Hz, 3.6 A;
100 VAC to 240 VAC, 50 Hz to 60 Hz, 4.0 A
Ultra Small
Form Factor 200 W 758 BTU/hr 100 VAC to 240 VAC, 50 Hz to 60 Hz, 2.9 A
Coin-cell
battery 3 V CR2032 lithium coin cell
NOTE: Heat dissipation is calculated by using the power supply wattage rating.
Physical Height Width Depth Weight
Mini-Tower 36.00 cm (14.17
inches) 17.50 cm (6.89
inches) 41.70 cm (16.42
inches) 8.87 kg (19.55 lb)
Desktop 36.00 cm (14.17
inches) 10.20 cm (4.01
inches) 41.00 cm (16.14
inches) 7.56 kg (16.67 lb)
Small Form
Factor 29.00 cm (11.42
inches) 9.26 cm (3.65
inches) 31.20 cm (12.28
inches) 5.70 kg (12.57 lb)
Ultra Small
Form Factor 23.70 cm (9.33
inches) 6.50 cm (2.56
inches) 24.00 cm (9.45
inches) 3.27 kg (7.20 lb)
Environmental
Temperature range:
Operating 10 °C to 35 °C (50 °F to 95 °F)
Storage –40 °C to 65 °C (–40 °F to 149 °F)
Relative humidity (maximum):
Operating 20% to 80% (non-condensing)
Storage 5% to 95% (non-condensing)
Maximum vibration:
Operating 0.26 GRMS
101