Riser Configurations
Servers can have many different riser configurations. Riser slots can support different PCIe generations.
Individuals installing a riser must ensure that the server supports the riser configuration.
Riser configurations ensure that the riser form factor does not interfere with heat sinks and air flow.
Expansion Cards
Nearly all servers offer the flexibility to add expansion cards. Expansion enables the organization to customize servers for a solution. Expansion cards can use a riser or plug directly into the system board.
Host Channel Adapters (HCA)
Host Channel Adapters (HCA) is optional card.
Host Channel Adapters (HCA) are deployed on PCI cards.
InfiniBand is an industry-standard, channel-based, switched fabric interconnect architecture for server and storage connectivity.
Features of HCAs
HCA는 스위치드 패브릭 토폴로지를 사용하여 여러 장치가 동시에 통신 가능
HCA는 양방향 직렬 버스(bidirectional serial bus)를 사용
HCA는 InfiniBand용이고, HBA는 Fibre Channel SAN 연결용
헷갈리지 말기!
SNAP I/O
SNAP I/O or SNAPI (also know as socket direct cards) enable both CPUs to share one adapter.
This is also deployed on PCI cards.
Also, SNAP I/O bypasses the UPI.
UPI(Ultra Path Interconnect)는 인텔 CPU 두 개가 서로 통신하는 통로입니다.
예를 들어: CPU0 ↔ CPU1 서로 메모리, I/O 요청을 주고받을 때 이 통로를 이용함
기존 NIC는 CPU 한쪽만 직접 연결되어 CPU 간 UPI를 타야 했지만,
SNAP I/O는 두 CPU가 직접 NIC에 접근할 수 있어 UPI 사용을 피하고, 지연을 줄이며, I/O 균형을 개선한다.
