Bandwidth: AGP vs. PCI vs. PCI Express

Bandwidth: AGP vs. PCI vs. PCI Express

PCI-Express should provide ample bandwidth for scalability well into the decade and perhaps even further. Currently, PCI-Express comes in five formats:

x1, x2, x4, x8, x12, x16. x4, x8, and x12 are likely to be reserved only for the server market while x1, x2, and x16 remain for the consumer for now.

Note: Each lane is comprised of 4 pins; x1 has one lane, x2 has two lanes, x4 has four lanes, and so forth. PCI-Express can transmit 100MB per second per pin.

Input/Output Bus Systems: [ISA = Industry Standard Architecture, EISA = Extended ISA, VLB = Video Electronics Standards Association (VESA) Local Bus, PCI = Peripheral Component Interconnect, AGP = Accelerated Graphics Port]

Graphics Standards	Possible Bandwidth
16-bit ISA	16MB/s
EISA	32MB/s
VLB	132MB/s
PCI	132MB/s
AGP 1x	264MB/s
AGP 2x	528MB/s
AGP 4x	1056MB/s
AGP 8x	2112MB/s
PCIe x1	500MB/s (Single Data Lane - Both Directions)
PCIe x2	1000MB/s (Dual Data Lane - Both Directions)
PCIe x4	2000MB/s (Quadruple Data Lane - Both Directions)
PCIe x8	4000MB/s (Eight Data Lane - Both Directions)
PCIe x12	6000MB/s (Twelve Data Lane - Both Directions)
PCIe x16	8000MB/s (4000MB/s Per Direction (Two Directions))

출처 : http://www.viperlair.com/articles/editorials/pcie/