18
System
TS-251C
TS-251/
TS-251-4G
TS-251A-2G /
TS-251A-4G
CPU
Dual-core Intel
®
Celeron™ 2.41GHz
(up to 2.58GHz)
Dual-core Intel
®
Celeron™ 2.41GHz
(up to 2.58GHz)
Dual-core Intel
®
Celeron™ 1.6GHz (up
to 2.48GHz)
Memory
1GB DDR3L
1GB / 4GB DDR3L
(Expandable RAM, up
to 8GB)
2GB / 4GB DDR3L
(Expandable RAM, up
to 8GB)
Flash
512MB
512MB
512MB
Memory
replaceable
-
✔
(Compatible with
DDR3L RAM)
✔
(Compatible with
DDR3L-1600 RAM)
Number of RAM
slots
-
2(SODIMM)
2(SODIMM)
Number of hard
drive slots
2 (3.5” HDDs only)
2
2
IR sensor
✔
(QNAP remote
control: RM-IR002)
✔
(QNAP remote
control: RM-IR002)
✔
(QNAP remote
control: RM-IR002)
System
TS-451 /
TS-451-4G
TS-451A-2G /
TS-451A-4G
TS-451S
CPU
Dual-core Intel
®
Celeron™ 2.41GHz
(up to 2.58GHz)
Dual-core Intel
®
Celeron™ 1.6GHz (up
to 2.48GHz)
Dual-core Intel
®
Celeron™ 2.41GHz
(up to 2.58GHz)
Memory
1GB / 4GB DDR3L
(Expandable RAM, up
to 8GB)
2GB / 4GB DDR3L
(Expandable RAM, up
to 8GB)
1GB DDR3L
(Expandable RAM, up
to 8GB)
Flash
512MB
512MB
512MB
Memory
replaceable
✔
(Compatible with
DDR3L RAM)
✔
(Compatible with
DDR3L-1600 RAM)
✔
(Compatible with
DDR3L RAM)
Number of RAM
slots
2 (SODIMM)
2(SODIMM)
2 (SODIMM)
Number of hard
drive slots
4
2
4 (2.5” only)
IR sensor
✔
(QNAP remote
control: RM-IR002)
✔
(QNAP remote
control: RM-IR002)
✔
(QNAP remote
control: RM-IR002)