ISA, EISA, PCI Statistics

ISA, EISA, PCI Statistics

Bus type	Data Bus Width	Clock Speed	Bus Mastery Support	Data Transfer Rate
8-bit ISA	8	4.77 MHz	No	Up
16-bit ISA	16	8 MHz	No	Up to 8 MB per second
EISA	32	8 MHz	Yes	Up to 33 MB per second
PCI	32 or 64	Depends on CPU Speed (33 and 66 MHz are typical)	Yes	Depends on clock speed (132 and 264 MB per second are typical)

You should also know the following facts about EISA, ISA, and PCI slots:

• PCI slots are normally white plastic.
• 64-bit PCI cards are often backwards compatible with 32-bit PCI slots.
• PCI was designed to be used with Plug-and-Play.

·         Riser Card Facts

·         An Audio Modem Riser (AMR) is an add-on board which supplements motherboard functionality. An AMR typically provides audio and modem functionality. Separating these functions from the motherboard is a valuable asset to motherboard design technique. By offloading analog functions from the system board, it is easier to extend the design specification of the motherboard itself without having to factor in these components. A Communication and Network Riser (CNR) is a riser card or daughter-board similar to an AMR. A CNR typically contains audio, modem and or network card functionality.

VESA and AGP Statistics

Bus type	Data Bus Width	Clock Speed	Bus Mastery Support	Data Transfer Rate
VESA	32	Depends on CPU speed (33 MHz is typical)	Yes	Depends on the clock speed (44-105 MB per second is typical)
AGP	32	Depends on CPU speed (66 MHz is typical)	N/A	Up to 533 MB per second

Additional AGP facts you should know:

• The AGP bus has a direct connection to the CPU.
• AGP uses direct memory execute (DIME), which allows AGP to share system memory with the CPU to do its calculations.
• AGP comes in the following specification:
• AGP 2x transfers to cycle of data during a single AGP clock beat
• AGP 4x transfers to cycle of data during a single AGP clock beat
• AGP 8x transfers to cycle of data during a single AGP clock beat
• AGP slots have a brown plastic casing and are generally smaller than PCI and ISA slots.
• AGP is best for high-speed, high-resolution, three-dimensional graphics.