Pci & Pci-Express - Acer Altos T350 F2 Faq

Altos T350 F2 FAQ (Frequently Asked Questions)
16. PCI & PCI-Express
1. Does Altos T350 F2 support PCI-Express Gen 3?
ANSWER: Yes.
2. Does Altos T350 F2 support PCI Express Base Spec 3.0?
http://www.pcisig.com/specifications/pciexpress/
ANSWER: Yes.
3. Is PCI-Express 3.0 backward compatible with PCI-Express 2.x and 1.x?
ANSWER: Yes.
4. What is the bit rate for PCIe 3.0 and how does it compare to prior generations of PCIe?
ANSWER: The bit rate for PCIe 3.0 is 8GT/s. This bit rate represents the most optimum tradeoff
between manufacturability, cost, power and compatibility.
The PCI-SIG analysis covered multiple topologies and configurations, including servers.
All of these studies confirmed the feasibility of 8GT/s signaling with low-cost enablers
and with minimal increases in power, silicon die size and complexity.
5. How does the PCIe 3.0 8GT/s "double" the PCIe 2.0 5GT/s bit rate?
ANSWER: The PCIe 2.0 bit rate is specified at 5GT/s, but with the 20 percent performance
overhead of the 8b/10b encoding scheme, the delivered bandwidth is actually 4Gbps. PCIe
3.0 removes the requirement for 8b/10b encoding and uses a more efficient 128b/130b encoding
scheme instead. By removing this overhead, the interconnect bandwidth can be doubled to
8Gbps with the implementation of the PCIe 3.0 specification. This bandwidth is the same
as an interconnect running at 10GT/s with the 8b/10b encoding overhead. In this way, the
PCIe 3.0 specifications deliver the same effective bandwidth, but without the prohibitive
penalties associated with 10GT/s signaling, such as PHY design complexity and increased
silicon die size and power. The following table summarizes the bit rate and approximate
bandwidths for the various generations of the PCIe architecture:
PCIe
architecture
PCIe 1.x
PCIe 2.x
PCIe 3.0
6. Where could I find more information about PCI-Express 3.0?
ANSWER: Please go to PCISIG web site.
http://www.pcisig.com/specifications/pciexpress/
7. Is PCI-Express compatible with PCI or PCI-X?
ANSWER: No. PCI-Express is a different technology. PCI-Express adapters cannot be installed
on PCI or PCI-X slots. PCI or PCI-X adapters cannot be installed on PCI-Express slots.
Interconnect
Raw bit rate
bandwidth
2.5GT/s
5.0GT/s
8.0GT/s
Bandwidth per
lane per
direction
2Gbps ~250MB/s
4Gbps ~500MB/s
8Gbps ~1GB/s
50
Total
bandwidth for
x16 lnk
~8GB/s
~16GB/s
~32GB/s