QNAP TS-639/3TB Tower vs QNAP TS-639/6TB Tower

Comparison of TS-639/3TB, TS-639/6TB

21 specifications	A QNAP TS-639/3TB Tower Model TS-639/3TB View product	B QNAP TS-639/6TB Tower Model TS-639/6TB View product
Storage1 differ
Total installed storage capacityDiffers	3 TB	6 TB
Number of storage drives supported	6	6
Processoridentical
Processor frequency	1.6 GHz	1.6 GHz
Memoryidentical
Internal memory	1 GB	1 GB
Internal memory type	DDR2	DDR2
Flash memory	128 MB	128 MB
Ports & interfacesidentical
Ethernet LAN (RJ-45) ports	2	2
USB 2.0 ports quantity	5	5
eSATA	Yes	Yes
Designidentical
Chassis type	Tower	Tower
Number of fans	2 fan(s)	2 fan(s)
Poweridentical
Output power	250 W	250 W
Weight & dimensionsidentical
Weight	5.2 kg	5.2 kg
Operational conditionsidentical
Operating temperature (T-T)	0 - 40 °C	0 - 40 °C
Operating relative humidity (H-H)	0 - 95%	0 - 95%
Other featuresidentical
Compatible operating systems	Windows 2000/XP/Vista/7/Server 2003/2008, Mac OS X, Linux, Unix	Windows 2000/XP/Vista/7/Server 2003/2008, Mac OS X, Linux, Unix
Dimensions (WxDxH)	257 x 235 x 175 mm	257 x 235 x 175 mm
Fan	2x90mm	2x90mm
Link/Act LED	Yes	Yes
Power requirements	100 - 240V	100 - 240V
Connectivity LEDsKnown for one	—Unknown — not stated by the source	Yes

A dash means the value is not stated by the source. Unknown values are never counted for or against a product, and there is no overall score.