Tech+ Full Review

Printing process

Toner attracted to areas of lesser charge on the drum



Cache

L3 - larger, slower, shared across cores

L2 - intermediate between L3 and L1

L1 - smallest and fastest cache level in a processor; sits closest to CPU cores (can deliver data with the least latency)



Hexadecimal

Base-16 system

0-9, A-F represents 10-15



Byte conversion

1,048,576 kb in one gb



Speed throughput units

From fastest to slowest…

Tbps

Gbps

Mbps

Kbps



Troubleshooting steps



Touchscreen types

Resistive touchscreens - rely on pressure; more accurate, less responsive

Capitative touchscreens - detect changes in electrical current; less accurate, more responsive



Server-based computer: think data centers?

  • AMD EPYC embedded processors

  • SATA 3.0 SSDs – reliable, compatible storage devices



Gyroscope detects device’s rotation



IoT:

Internet of things

Privacy concerns because personal data is stored in the cloud



Motherboard form factors:

Baby-AT: older, larger; unsuitable for new gaming systems

Pico-ITX: smaller; unsuitable for gaming hardware due to limited power capacity

Mini-ITX: common compact form factor in modern, small gaming builds



Volatile/non-volatile storage:

Volatile: holds data and loses it when the computer is turned off

Volatile examples: Dynamic RAM

Non-volatile examples: ROM (used for firmware), hard drives, flash drives, 



Hard drive: spinning metal platters and read/write system to write and store large amounts of data permanently

Flash drive: Solid state (SSD) memory chips and circuits to store data without moving parts; SSDs have a finite number of write operations, but their lack of moving parts is an advantage. SSDs are more expensive.



Storage solutions:

DAS Storage - connects directly to a single computer

NAS Storage - network-shared access, supports RAID configurations; centralized, long-term file storage for multiple users



Drive interfaces:

Drive interface = the physical and electrical connection used to link a storage device (hdd, ssd, optical drive) to a computer’s motherboard/controller

SATA: standard for hard drives and SSDs; 7-pin data cable; 15-pin power connector; support for hotswapping

SAS: high performance; used in data centers and high-enterprise servers



Airplay - streams audio and video

NFC - tap-to-pay transactions



Network bandwidth is always finite



Virtualization

Type 2 hypervisor: runs on top of the host operating system; used for client-side testing

Type 1 hypervisor: runs directly on physical machine as the OS: used in server-side virtualization; high security

KVM: linux, used for virtualization support, not used in place of OS



Categories of cloud computing services

Infrastructure as a service: provides virtualized hardware resources

Platform as a service: offers development environment for building apps

Software as a service: delivered through a browser as a complete, ready-to-use service 

Middleware as a service: provides integration and messaging components



End user computing

The framework of technology, processes, and policies that allow employees to securely access company applications, desktops, and data from any device and location



Cloud environments

On-premise clouds are hosted only within the company’s premises

Hybrid clouds combine on-premises/private resources with public cloud services, which introduces external infrastructure 

Private cloud can be hosted on-premises only or by a third party (does not guarantee no external infrastructure)



Switch provides additional wired ports and does not improve wireless coverage

  • LAN (local access network) is supported by a switch

Router broadcasts a wireless network and can be configured to extend coverage



Network-based firewalls usually require an embedded hardware device used to inspect and filter traffic

Software-only firewalls are usually employed by individual users



802.11 Standards

802.11n - lower maximum throughput (>1 gbps)

802.11g - older standard limited to 54 mbps

80.11ax (WiFi 6) - supports multi-gigabit speeds that can reach beyond 8 gbps; stronger range and efficiency compared to earlier standards

802.11ac - fast, but does not reach 8 gbps; shorter effective range than ax/WiFi 6



Video card performance expressed in teraflops

  • Calculated with math involving floats or real numbers, including decimals



Backups

Directly attached local storage backups are the fastest

Cloud storage depends on internet speed, which is slower than local transfer rates



Steps for updating the device driver

  1. Open device manager

  2. Locate specific device category

  3. Search for drivers

  4. Update 



macOS

Activity monitor to monitor system health and functionality



Ubuntu

System monitor to monitor system health and functionality

Linux-based server OS

Widely used for web server hosting and management 



Kinetic sensors

Accelerometer + gyroscope

Detects motion

Tilt and shake rely on these



Filesystems

Extended File System (XFS): high performance, designed for Linux, supports large partitions

Apple file system (APFS): replaced old HFS; default for iOS

File allocation table (FAT32): legacy file system limited to a max file size of 4GB