Computer Architecture: Interconnection Networks

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What is the main difference between static and dynamic networks in interconnection networks?

Static networks consist of point-to-point communication links between processors, whereas dynamic networks are built using switches and communication links that are connected dynamically.

What is network latency in the context of static networks?

Network latency is the time to transfer a message through the network.

What is bisection bandwidth in static networks?

Bisection bandwidth is the bisection width times the bandwidth of the links.

What is the primary form of data exchange between parallel tasks in message-passing platforms?

Exchanging messages. Signup and view all the answers

What is the characteristic of shared-address-space platforms?

All of the memory is accessible to all processors. Signup and view all the answers

What is the diameter of a static network?

The maximum shortest path between any two processors. Signup and view all the answers

What is the cost of a static network?

The number of links in the network. Signup and view all the answers

What is the significance of bisection width in static networks?

It is the minimum number of links that must be cut to partition the network into two equal or almost equal halves. Signup and view all the answers

What is the primary characteristic that defines a Uniform Memory Access (UMA) platform?

The time taken by a processor to access any memory in the network is the same. Signup and view all the answers

What is the main difference between UMA and NUMA architectures?

The number of memory controllers used. Signup and view all the answers

Which type of memory access is faster, UMA or NUMA?

NUMA Signup and view all the answers

What is the limitation of Uniform Memory Access?

Limited bandwidth. Signup and view all the answers

What type of applications is Non-uniform Memory Access suitable for?

Real-time applications. Signup and view all the answers

In a UMA architecture, what is the characteristic of memory access time?

It is balanced or equal. Signup and view all the answers

What is the main advantage of NUMA over UMA?

Faster memory access and higher bandwidth. Signup and view all the answers

What is the difference between UMA and NUMA in terms of memory controller usage?

UMA uses a single memory controller, while NUMA uses multiple memory controllers. Signup and view all the answers

What is the main function of interconnection networks in parallel computers?

carry data between processors and to memory Signup and view all the answers

What is the assumption of the Parallel Random Access Machine (PRAM) model?

all processors operate synchronously under a single clock and can randomly access a large shared memory Signup and view all the answers

What is the cost of a switch in an interconnection network in terms of its degree?

grows as the square of the degree of the switch (N^2) Signup and view all the answers

What determines the performance of the network in a parallel computer?

the relative speeds of the I/O and memory buses Signup and view all the answers

What is the main difference between static and dynamic interconnection networks?

static networks consist of point-to-point communication links, while dynamic networks are built using switches and communication links Signup and view all the answers

What is the per-hop time in current parallel computers?

quite small, and can be ignored for most parallel algorithms Signup and view all the answers

What is the total communication cost for a message of size m words to traverse l communication links?

not specified in the text, but is a function of m and l Signup and view all the answers

What is the main characteristic of a PRAM machine?

all processors operate synchronously under a single clock Signup and view all the answers

What is the main characteristic of non-uniform Memory Access?

Memory access time is not equal. Signup and view all the answers

What is the primary method of programming used in Message-Passing Platforms?

Send and receive messages (variants of). Signup and view all the answers

What is the advantage of Message Passing platforms in terms of hardware support?

It requires little hardware support, other than a network. Signup and view all the answers

What is the sum of in the communication cost of a message in a parallel machine?

The time to prepare a message for transmission and the time taken by the message to traverse the network to its destination. Signup and view all the answers

What is the startup time (ts) in the context of message communication?

The time required to handle a message at the sending and receiving nodes, including the time to prepare the message. Signup and view all the answers

What is the per-hop time (th) in the context of message communication?

The time taken by the header of a message to travel between two directly connected nodes in the network. Signup and view all the answers

What is the per-word transfer time (tw) in the context of message communication?

The time taken by each word to traverse the link, given by tw = 1/r, where r is the channel bandwidth in words per second. Signup and view all the answers

What is the total time taken to transmit a message of size m through a network with l links?

th + twm, where th is the per-hop time and tw is the per-word transfer time. Signup and view all the answers