VIDEO
Bus architecture
A Communication Path
Internal PC Growth
System expansion
The expansion bus
"Width" in bits
Big roads, little roads
Width is changing to bandwidth
Clock speed of bus
The expansion bus gets its own clock
1 MHz (megahertz) = 1 million cycles per second
1 GHz = 1000 MHz
Clock speed does not necessarily equal transfer rate
DDR3 SDRAM can transfer 64 times the memory clock speed
Conventional PCI (Peripheral Component Interconnect)
Created in 1994
A common expansion interface
32-bit and 64-bit bus width
Throughput varies by bus version
133 MB/s (32-bit at 33 MHz)
266 MB/s (32-bit at 66 MHz or 64-bit at 33 MHz
533 MB/s (64-bit at 66 Mhz)
PCI 32-bit expansion card
PCI 64-bit expansion card
Mini PCI
PCI for laptops
Shrink it down for mobile use.
Expand features of laptops
Wifi, mobile broadband, etc
No access to the card
It's inside the laptop
Can't touch it
PCI-X (PCI eXtended)
Designed for servers
Higher Bandwidth
Four times the clock speed
Built to handle higher speed, network, and storage
1,064 MB/s capacity
THIS IS NOT PCI EXPRES (completely different)
PCI Express
Also known as PCIe
Not really a bus in the traditional sense
Unidirectional serial "lanes"
Slower devices don't slow down everyone
One,two,four,eight,sixteen, or thirty-two full duplex lanes
x1, x2, x4, x8, x16, x32
"x" is pronounced "by"
i.e., "by 4," "by 16"
PCI Express throughout
Different versions of PCIe
Improvement in speed with each iteration
Per-lane throughput in each direction
-v1.x: 250 MB/s
-v2.x: 500 MB/s
v3.0 : 985 MB/s (8 GT/s)
v4.0 : 1969 MB/s (16 GT/s)
CNR ( Communications and Networking Riser)
Modular riser for networking, modem, audio, etc.
AGP ( Accelerated Graphics Port)
Almost always called AGP
Designed to cover the gap between PCI and PCI Express
Difficult to find AGP today
AGP Versions
AGP 1x (266MB/s),
AGP 2x (522MB/s)
AGP 1.0, 3.3V
AGP 4x (1.07 GB/s)
AGP 8x (2.1 GB/s)