Glossary

CPU (Central Processing Unit)

CPU (Central Processing Unit) - otherwise known as a processor - is an electronic circuit that can execute computer programs. Both the miniaturization and standardization of CPUs have increased their presence far beyond the limited application of dedicated computing machines. Modern microprocessors appear in everything from automobiles to mobile phones.

The clock rate is one of the main characteristics of the CPU when performance is concerned. Clock rate is the fundamental rate in cycles per second (measured in hertz, kilohertz, megahertz or gigahertz) for the frequency of the clock in any synchronous circuit. A single clock cycle (typically shorter than a nanosecond in modern non-embedded microprocessors) toggles between a logical zero and a logical one state.

With any particular CPU, replacing the crystal with another crystal that oscillates with twice the frequency will generally make the CPU run with twice the performance. It will also make the CPU produce roughly twice the amount of waste heat.

Engineers are working hard to push the boundaries of the current architectures and are constantly searching for new ways to design CPUs that tick a little quicker or use slightly less energy per clock. This produces new cooler CPUs that can run at higher clock rates.

Scientists also continue to search for new designs that allow CPUs to run at the same or at a lower clock rate as older CPUs, but which get more instructions completed per clock cycle.

The clock rate of a processor is only useful for providing comparisons between computer chips in the same processor family and generation.

Clock rates can be very misleading since the amount of work different computer chips can do in one cycle varies. Clock rates should not be used when comparing different computers or different processor families. Rather, some kind of software benchmarks should be used.

Smartphones are equipped with more advanced embedded chipsets that can do many different tasks depending on their programming.

The performance of the CPU that's at the core of the chipset is vital for the daily user experience and the general computing performance of the smartphone. People tend to use the clock rate of the main CPU to compare the performance of competing end products. But as we already pointed out, the clock rate of a processor is only useful for providing performance comparisons between computer chips in the same processor family and generation. For all other purposes, it's best to use software benchmarks for determining comparative performance.

Related terms:

0 - 9

2G | 3G | 3GP video | 802.11

A

A-GPS (Assisted GPS) | A2DP (Advanced Audio Distribution Profile) | AAC (Advanced Audio Coding) | Accelerometer | Airplane mode | Alarm Clock | Alphanumeric | AMOLED display (Active-matrix organic light-emitting diode) | Analog | Android | Antenna | APN (Access Point Name) | Apple iOS | Audio jack | Auto-focus | AVRCP (Audio/Video Remote Control Profile)

B

Bada OS | Band | Bandwidth | Bar | Base Station | Bit | BlackBerry OS | BlackBerry Playbook OS | Bluetooth | bps (Bits per Second) | Brand | Broadband | Browser | Byte

C

Calculator | Calendar | Call alerts | Calling Plan | Camera | Capacitive Touchscreen | Car Kit | Carrier | CDMA (Code-Division Multiple Access) | CDMA2000 | Cell | Chipset | cHTML (Compact HyperText Markup Language) | CIF (Common Intermediate Format) | Clamshell | CMOS (Complementary metal-oxidesemiconductor) | Color depth | Concatenated SMS | Corning Gorillla Glass | CPU (Central Processing Unit) | Crosstalk | CSTN (Color Super Twisted Nematic) | CTIA | Custom ringtones

D

D-Pad (Direction Pad) | DC-HSDPA (Dual Carrier or Dual Cell High-Speed Downlink Packet Access) | Digital Zoom | Display type | DLNA (Digital Living Network Alliance) | DNSe (Digital Natural Sound engine) | Downlink | DRM (Digital Rights Management) | Dual-band | Dual-Mode | Dual-SIM | DVB-H (Digital Video Broadcasting - Handheld) | Dynamic Memory

E

EDGE (Enhanced Data for Global Evolution) | EDR (Enhanced Data Rate) | EGPRS | EGSM (Extended GSM) | Email client | EMS (Enhanced Message Service) | EV-DO | EV-DV | Exchangeable covers | External Antenna Jack | External Display

F

FCC (Federal Communications Commission) | Feature Phone | Femtocell | Firefox OS | Firmware | Fixed-focus | Flash Memory | Flight mode | Flip-down phone | FM Radio | FM Transmitter | Form factor | FOTA (Firmware Over-The-Air) | FPS (Frames Per Second) | Frame Error Rate | Frequency | FTP (File Transfer Protocol)

G

GB (Gigabyte) | Gbps (Gigabits per second) | Geo-tag | GPRS | GPS (Global Positioning System) | gpsONE | gpsOneXTRA Assistance technology | GPU (Graphics Processing Unit)

H

H.263 | Half-QWERTY keyboard layout | Handwriting recognition | Haptics | Hot Spot | Hot Swap | HSCSD (High-Speed Circuit Switched Data) | HSDPA (High-Speed Downlink Packet Access) | HSDPA+ (High-Speed Downlink Packet Access Plus) | HSP (Headset Profile) | HSUPA (High-Speed Uplink Packet Access) | HTML (Hypertext Markup Language) | Hz (Hertz)

I

iDEN (Integrated Digital Enhanced Network) | IMAP (Internet Message Access Protocol) | IMEI (International Mobile Equipment Identity) | IP (Internet Protocol) | IrDA (Infrared Data Association)

J

Java

K

KB (Kilobyte) | Kbps (Kilobits per second) | Key Guard | Key Lock Switch

L

Land line | LCD (Liquid Crystal Display) | LED (Light-Emitting Diode) | Li-Ion (Lithium Ion) | Li-Polymer (Lithium Polymer) | LiMo OS | Linux | Location-Based Services (LBS) | Lock code | Long SMS | Long term evolution (LTE) | Loudspeaker

M

Macro | Maemo OS | mAh | Mass Storage mode | MB (Megabyte) | Mbps (Megabit per second) | MeeGo OS | Megapixel | Memory card slot | Memory effect | Messaging | MHz (Megahertz) | Micro USB | microSD | microSDHC | Microsoft Exchange (Server) | MIDI (Musical Instrument Digital Interface) | MIDP (Mobile Information Device Profile) | Mil-Spec (MIL-STD) | Mini-USB | miniSD | MMC | MMCmobile | MMS (Multimedia Messaging Service) | Mobile games | Mobile IM (Instant Messaging) | Mobile WiMAX | Modem | Monochrome | MP3 (MPEG Layer 3) | MPEG (Motion Picture Experts Group) | MPEG-4 video | Multitouch input method | Music playback time (battery life) | Music Player

N

NAND Memory | Network capacity | Network coverage | NFC (Near Field Communication) | NiCd (Nickel Cadmium) | NiMH (Nickel Metal Hydride) | NOR Memory | Numeric keypad

O

OEM (Original Equipment Manufacturer) | OLED (Organic Light-Emitting Diode) | Optical Zoom | OS (Operating System) | OTA (Over-The-Air)

P

Packet Data | Pager | PC Sync | PCS (Personal Communications Service) | PDA (Personal Digital Assistant) | Phone Book Access (PBA) | Phonebook | PIM (Personal Information Manager/Management) | PIN code (Personal Identification Number) | Pixel | Pixel density (PPI) | Polyphonic ringtones | POP3 (Post Office Protocol) | Port | Predictive text input | PTT (Push-To-Talk) | PUK Code (PIN UnlocK Code) | Push

Q

QCIF (Quarter Common Intermediate Format) | Quad-band | QVGA (Quarter Video Graphics Array) | QWERTY keyboard layout

R

RAM (Random-Access Memory) | RBDS (Radio Broadcast Data System) | RDS (Radio Data System) | Resistive touchscreen | Resolution | Ringer ID | Ringing profiles | Ringtone | Roaming | ROM (Read-Only Memory) | RS-MMC (Reduced-Size Multi Media Card) | RSA (Rural Service Area) | RSS (Rich Site Summary) | Ruggedized (Rugged)

S

S60 user interface | SAP (SIM Access Profile) | SAR (Specific absorption rate) | Screen protection | SD (Secure Digital) | Secondary camera | Sensors | Side Keys | SIM | SIM lock | Single-Band | Skin | Smartphone | SMIL | SMS (Short Messaging Service) | SNS (Social network service) | Soft keys | Soft Reset | Speed Dial | Stand-by time (battery life) | Stereo Speakers | Streaming Video | Stylus | Sub-QCIF | SVGA | Symbian | SyncML

T

Talk time (battery life) | TCP/IP | TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) | TEST | Tethering | Text messaging (texting) | TFD (Thin Film Diode) | TFT (Thin Film Transistor) | Theme | To-Do list | Touchscreen | Trackball | Transflash | Transflective | Tri-band

U

UI (User Interface) | UIQ | UMA | UMTS | Unlocked phone | Upload | UPnP (Universal Plug and Play) | USB (Universal Serial Bus) | USIM

V

VGA (Video Graphics Array) | Video call | Video Codec | Voice dialing | Voice mail | Voice memo | VoIP (Voice over Internet Protocol) | VPN (Virtual Private Network)

W

WAP (Wireless Application protocol) | WCDMA(Wideband Code Division Multiple Access) | webOS | Wi-Fi | Windows Mobile | Windows Phone OS | Wireless email | WLAN | WMV (Windows Media Video)

X

Xenon flash