Random Access Memory (RAM) DDR (184 pins), DDR2 (240 pins), DDR3 (240 pins), and DDR4 (240 pins) are the different
types of DIMMs (288 pins). DDR (200 pin), DDR2 (200 pin), DDR3 (204 pin), and DDR4 RAM SODIMMs are examples of
RAM SODIMMs (260 pin). The following is an example of a DDR3‐1600 data transmission calculation: 1600 MT/s 8
= 12,800 megabits per second Dual‐channel is a 128‐bit bus with double width. Triple‐channel is a 192‐bit bus with three
times the width. Quad‐channel is a 256‐bit bus with four times the width. CL or CAS is a measure of latency.
To reduce overheating, a “dual‐rail” PSU separates and controls the current in each wire.
Hard drives store data. The included types are as follows:
 SATA: A serial ATA utilizes a 15‐pin power connector and 7‐pin data connector. Rev 1 (1.5 Gb/s), Rev 2 (3 Gb/s), Rev
3 (6 Gb/s), Rev 3.2 (SATA Express) (16 Gb/s).
Redundant Array of Independent Disk (RAID): RAID 0 refers to striping, while RAID 1 refers to mirroring, and RAID 5 refers
to striping with parity. In a striped system, RAID 10 refers to mirrored sets. RAID 0 indicates that the system is not fault‐
tolerant. Disk duplexing is achieved by employing RAID 1 with two disk controllers.
Networking protocols:
 FTP (File Transfer Protocol). Port 21
 SSH (Secure Shell). Port 22
 Telnet Port 23
 SMTP (Simple Mail Transfer Protocol) Port 25 (can use port
587)
 DNS (Domain Naming System). Port 53
 HTTP (Hypertext Transfer Protocol).Port 80
 POP3 (Post Office Protocol). Port 110
 IMAP (Internet Message Access Protocol). Port 143
 HTTPS (HTTP Secure). Port 443
 SMB (Server Message Block). Port 445, 137–139
 AFP (Apple Filing Protocol). Port 548 (or 427)
 RDP (Remote Desktop Protocol). Port 3389
Cabling standards:
 Category 3: Rated for 10 Mb/s
 Category 5: Rated for 100 Mb/s
 Category 5e: Rated for 100 Mb/s and gigabit networks
 Category 6/6a: Rated for gigabit and 10 Gb/s networks
 Category 7: Rated for gigabit and 10 Gb/s networks
 Plenum‐rated cable: Fire‐resistant cable created for
the following: airways, conduits and areas sprinklers
cannot reach.
Wireless Ethernet versions, including name, data transfer rate,
frequency and modulation used:
 802.11a, 54 Mb/s, 5 GHz
 802.11b, 11 Mb/s, 2.4 GHz
 802.11g, 54 Mb/s, 2.4 GHz
802.11n, 300/600 Mb/s, 5 and 2.4 GHz802.11ac, 1.7 Gb/s and
beyond, 5 GHz
Networking connectors: twisted pair (RJ45, RJ11); fiber
optic (SC, ST, and LC); coaxial (F‐connector, BNC).
568B standard: 1. White/orange, 2. Orange, 3.
White/green, 4. Blue, 5. White/ blue, 6. Green, 7.
White/brown, 8. Brown.
IPv4 addresses are 32‐bit dotted‐decimal numbers,
such as 192.168.1.1.
They can be manually entered or allocated dynamically
(DHCP). The following IP classes are available:

Class A range: 1–126, subnet mask: 255.0.0.0.
Private: 10.x.x.x

Class B range: 128–191, subnet
mask: 255.255.0.0. Private: 172.16.0.0–
172.31.255.255

Class C range: 192–223, subnet mask:
255.255.255.0. Private: 192.168.x.x Loopback is
127.0.0.1
APIPA is 169.254.x.x (also known as link‐local)
Classless Inter‐Domain Routing(CIDR) addresses
(example: 10.150.23.58/24) need a prefix. The /24
denotes a 255.255.255.0 subnet mask.
IPv6 addresses are 128‐bit hexadecimal numbers, such
as 2001:7120:0000:8001: 0000:0000:0000:1F10.
::1 is the loopback address. Unicast
The most popular kind of IP address is IPv6, which is
allocated to a single interface.
1000 Mb/s (gigabit Ethernet) and 10 Gb/s are common
network speeds (10 Gb Ethernet).
Custom PCs includes Workstations for audio and video are included. CAD/CAM workstations will require powerful
multicore CPUs, high‐end video cards, and maximized RAM; home server PCs (gigabit NICs, RAID arrays, print sharing, file
sharing, media streaming); HTPCs (compact form factor, surround sound, HDMI output, TV tuner); gaming PCs (multicore
CPU, high‐end video, high‐def sound, high‐end cooling); thin clients (low resources, meets minimum OS requirements,
relies on server, diskless, embedded OS, network connectivity); virtualization workstations (low resources, meets
minimum OS needs, relies on server, diskless, embedded OS, network communication) (strong CPU and plenty of RAM).
Type 1 is the bare or native metal hypervisor. Type 2 is hosted and operates on top of the operating system.