Questions tagged [low-latency]

For questions pertaining to the measurement or improvement of latency in a system.

In computing terms, describe the time it takes to perform an action. Low latency implies this should be particularly short. It is usually in the range of timings which cannot be seen, only measured.

Low Latency implies that there is a measure for the latency of critical portions of the system and that it should meet this latency requirement a high percentage of the time e.g. 99%, 99.9%, 99.99% or worst case.

This could be any where from 10 nano-second to 100 milli-seconds depending on the context.

Questions which tag low latency should give measurable timings and percentage to reach that as the solution to follow is very dependant on these measures.

Without a latency measure to go by often the simplicity of the solution should be the target which will produce quick application with minimal complexity/effort.

416 questions
5
votes
2 answers

Count of memory copies in *nix systems between packet at NIC and user application?

This is just a general question relating to some high-performance computing I've been wondering about. A certain low-latency messaging vendor speaks in its supporting documentation about using raw sockets to transfer the data directly from the…
Michael_73
  • 353
  • 3
  • 11
5
votes
2 answers

compensating latency on ARM interrupts?

I'm working on a project on a STM32F4 CPU, generating signals. I have a generic timer on CPU clock (no prescaler) on a STM32 triggering interrupts on overflow, to generate a periodic signal with GPIO afterwards. I need to trigger thr GPIO at a very…
makapuf
  • 1,370
  • 1
  • 13
  • 23
5
votes
1 answer

Where can I find some sample Java code for SolarFlare OpenOnLoad Kernel Bypass?

Simple questions to get anyone started: I know I need a special Network Interface Card (nic) to do this. I am assuming it has to be the ones SolarFlare makes. What is the cheapest one I can get that will allow me to implement and test kernel…
chrisapotek
  • 6,007
  • 14
  • 51
  • 85
5
votes
1 answer

Java: low latency performance measurements

Is the process of measuring performance for low latency Java apps different from that of measuring performance for non low latency Java apps? If yes, how so, and are there any specific tools used for measuring low latency performance? EDIT: e.g.…
shrini1000
  • 7,038
  • 12
  • 59
  • 99
5
votes
3 answers

Windows 8 - low latency audio

I'm considering developing an app for the upcoming Windows 8. The app requires low-latency audio recording and playback, and I'm trying find out whether the OS will support that (as opposed to other platforms). So what I'd like to know is: Is there…
kshahar
  • 10,423
  • 9
  • 49
  • 73
4
votes
5 answers

Fast Audio Input/Output

Here's what I want to do: I want to allow the user to give my program some sound data (through a mic input), then hold it for 250ms, then output it back out through the speakers. I have done this already using Java Sound API. The problem is that…
Brandon Montgomery
  • 6,924
  • 3
  • 48
  • 71
4
votes
1 answer

Log4j AsyncAppender

We have a high-speed, high-volume application, which is using log4j. Typically we have been using the SyslogAppender, thinking that it's the lightest weight, fastest appender. But we are seeing high CPU utilization from SYSLOG under high volume…
Sam Goldberg
  • 6,711
  • 8
  • 52
  • 85
4
votes
1 answer

Comparison of ZeroMQ's latency / metrics with that of its competitors

Does anyone know where you can find performance details on ZeroMQ latency vs. competitors like 29 West LBM? Looks considerably cheaper, but I cannot find any metrics to decide which is more suitable.
DD.
  • 21,498
  • 52
  • 157
  • 246
4
votes
1 answer

Why is it faster sending data as encoded string than sending it as bytes?

I'm playing with pyzmq for inter-process transfer of 4k HDR image data and noticed that this: byt = np.array2string(np.random.randn(3840,2160,3)).encode() while True: socket.send(byt) is much much faster than: byt =…
roque2205
  • 49
  • 2
4
votes
1 answer

Lower latency from webcam cv2.VideoCapture

I'm building an application using the webcam to control video games (kinda like a kinect). It uses the webcam (cv2.VideoCapture(0)), AI pose estimation (mediapipe), and custom logic to pipe inputs into dolphin emulator. The issue is the latency.…
Yonah Karp
  • 581
  • 7
  • 22
4
votes
1 answer

Efficient collection and transfer of scattered sub-arrays in Chapel

Recently, I came across Chapel. I liked the examples given in the tutorials but many of them were embarrassingly parallel in my eyes. I'm working on Scattering Problems in Many-Body Quantum Physics and a common problem can be reduced to the…
4
votes
3 answers

Low Latency Networking Technqiues and Silver-Bullets

After some basic googling of low-latency networking I've come up with the following list of things programmers and system designers should consider when embarking on low latency networking: The design of the hardware, systems and protocols have to…
Gelly Ristor
  • 573
  • 1
  • 6
  • 17
4
votes
2 answers

CyclicDist goes slower on multiple locales

I tried doing an implementation of Matrix multiplication using CyclicDist module. When I test with one locale vs two locales, the one locale is much faster. Is it because the time to communicate between the two Jetson nano boards is really big or is…
4
votes
1 answer

Render canvas faster than 60 times per second?

My JS code: var c = document.getElementById("myCanvas"); var ctx = c.getContext("2d"); var mouse = {x:0,y:0} const times = []; let fps; function refreshLoop() { window.requestAnimationFrame(() => { const now = performance.now(); while…
4
votes
4 answers

Is C++11 is faster than C++03 in terms of efficiency?

I work in trading firm and here latency matters a lot. The project assigns to me is developed using a mix of c and c++98 parts, But I believe we can make same project using C++11 without losing efficiency. As discussed with my seniors, they say you…
Arun Pal
  • 687
  • 7
  • 28