Cheat Sheets

RAM DIMM Gens

DDR 184 pin, DDR2 240 pin, DDR3 240 pin, and DDR4 288 pin

RAM SODIMM Gens

DDR 200 pin, DDR2 200 pin, DDR3 204 pin, DDR4 260 pin

RAM Channel types

Dual-channel: 2x width of 128-bit bus

Triple-channel: 3x width of 192-bit bus

Quad-channel: 4x width of 256-bit bus

RAM latency

The delay between CPU requesting data and RAM delivering it. Categorized as CAS Latency (CL), with categories like CL16 or CL30, lower numbers mean faster response time

HDD RPM speeds

5400, 7200, 10000, 15000

HDD form factors

3.5”, 2.5”

SSD interfaces

NVMe SATA

PCIe

SDD form factors

M.2, mSATA

SSD PCIe data lanes

x1, x2, x8, x16

Bluetooth transmission range lengths

Class I: 100m

Class II: 10m (most popular)

Class III: 1m (unpopular)

Bluetooth maximum data transfer rate

Version 1: 721 Kb/s

Version 2: 2.1 Mb/s

Version 3: 24 Mb/s

Wifi Versions, data rate and frequency modulation

802.11a: 54 Mb/s, 5 GHz

802.11b: 11Mb/s, 2.4 GHz

802.11g: 54 Mb/s, 2.4 GHz

802.11n, 300/600 Mb/s, 2.4 and 5 GHz

802.11ac, 1.7 Gb/s, 5 GHz

802.11ax, 9.6 Gb/s, 2.4 and 5 and 6 GHz

3G v 4G v 5G, Bandwidth, Speed, Latency

3G: 25 MHz, 2 Mbps, 500 ms

4G: 100 MHz, 100 Mbps, 50 ms

5G: 300 GHz, 10 Gbps, 1 ms

Switch vs Router

Connects computers in LAN, v Connects 2+ LANs to the Internet

Port 20,21

FTP, File Transfer Protocol, Unencrypted

Port 22

SSH, Secure Shell, Encrypted

Port 23

Telnet, Unencrypted

Port 25

SMTP, Simple Mail Transfer Protocol, Unencrypted

Port 53

DNS, Domain Naming System

Port 67/68

DHCP, Dynamic Host Configuration Protocol

Port 80

HTTP, Hypertext Transfer Protocol, Unencrypted

Port 110

POP3, Post Office Protocol

Port 137,138,139

NetBIOS

Port 143

IMAP, Internet Message Access Protocol

Port 389

LDAP, Lightweight Directory Access Protocol, Unencrypted

Port 443

HTTPS, Hypertext Transfer Protocol Secure, Encrypted

Port 445

SMB/CIFS, Server Message Block/Common Internet File System

Port 3389

RDP, Remote Desktop Protocol