What is an effective obtain latency? This journey delves into the fascinating world of community efficiency, exploring how obtain speeds have an effect on your on-line expertise. From streaming movies to downloading large recordsdata, understanding obtain latency is essential for a easy and satisfying on-line journey. We’ll uncover the secrets and techniques behind optimum obtain speeds, exploring elements like community infrastructure, server areas, and even the mysterious world of web protocols.
Get able to unlock the mysteries of quick downloads!
Obtain latency, basically the delay between requesting a file and receiving it, considerably impacts person expertise. Components like community congestion, server distance, and the intricacies of community protocols all play a task. This complete information gives a transparent understanding of obtain latency, from its definition to optimization methods. We’ll additionally discover the influence of latency on numerous functions, highlighting its significance in on-line gaming, video conferencing, and file sharing.
So, buckle up for an informative experience into the world of obtain speeds!
Defining Obtain Latency
Obtain latency, an important facet of on-line experiences, usually goes unnoticed. It is the time it takes for information to journey from a server to your machine. Think about ordering a pizza on-line; obtain latency is the time from clicking “submit” to the pizza order showing in your display. This delay, whereas generally imperceptible, considerably impacts person expertise and utility efficiency.Understanding obtain latency is essential to optimizing community efficiency and making certain easy on-line interactions.
Components comparable to server distance, community congestion, and the effectivity of the community infrastructure all contribute to the general time it takes for a file to succeed in your machine. This information empowers us to deal with and enhance the web expertise.
Defining Obtain Latency
Obtain latency is the delay skilled when transferring information from a distant server to a neighborhood machine. It is a crucial measure of community efficiency, straight affecting how shortly recordsdata, functions, and internet pages load. This metric is prime to evaluating and enhancing the person expertise.
Components Contributing to Obtain Latency
Quite a few elements affect obtain latency, creating a posh interaction of parts. These elements may be broadly categorized as follows:
- Server Distance: The bodily distance between the server internet hosting the info and your machine considerably impacts latency. Information touring throughout continents will naturally take longer than information touring throughout the identical metropolis. Consider it like sending a letter; a letter to a close-by city will arrive quicker than one to a distant nation.
- Community Congestion: When many customers concurrently request information from a server, the community can grow to be congested. This congestion results in delays as information packets compete for transmission, much like visitors jams on a busy freeway. Peak hours on in style web sites usually expertise elevated latency attributable to excessive visitors quantity.
- Community Infrastructure: The standard and effectivity of the community infrastructure play a crucial function. Out-of-date or under-maintained networks will lead to greater latency in comparison with fashionable, high-capacity networks. That is much like a freeway with poor upkeep inflicting slower speeds.
- Server Assets: If the server internet hosting the info is overloaded or underpowered, it’s going to battle to course of and ship the requested information. That is akin to a restaurant kitchen being overwhelmed with orders, leading to delayed service.
- Shopper-Facet Components: Whereas much less frequent, elements in your finish can affect latency, comparable to your web connection velocity or your machine’s processing capabilities. Think about attempting to obtain a high-resolution picture on a gradual web connection.
Distinction Between Obtain and Add Latency
Obtain latency, as talked about, is the time taken for information to journey from a server to your machine. Add latency, alternatively, is the time taken for information to journey out of your machine to a server. Consider importing a photograph to a social media platform; the add latency is the time it takes for the picture to succeed in the server.
Understanding this distinction is essential for optimizing each sending and receiving information.
Evaluating Obtain Latency with Different Community Metrics
A comparability desk highlighting obtain latency alongside different crucial community metrics gives a complete understanding.
| Metric | Definition | Affect on Obtain Latency |
|---|---|---|
| Obtain Latency | Time taken for information switch from server to machine | Straight impacts obtain velocity |
| Bandwidth | Most information switch fee | Increased bandwidth usually results in decrease latency |
| Packet Loss | Share of information packets misplaced throughout transmission | Packet loss will increase latency and information corruption |
| Jitter | Variation in packet arrival instances | Jitter can introduce unpredictable latency spikes |
Measuring Obtain Latency
Unveiling the secrets and techniques of obtain velocity, understanding the right way to gauge the responsiveness of your web connection is essential. Whether or not you are a seasoned gamer, a demanding streamer, or simply somebody who enjoys massive file transfers, figuring out the right way to measure latency empowers you to determine bottlenecks and optimize your on-line expertise. The strategies for measuring latency are as numerous because the web itself, from easy browser exams to classy community monitoring instruments.Delving into the realm of obtain latency measurement, one should perceive that exact quantification is essential to figuring out and addressing efficiency points.
Instruments and strategies vary from available on-line utilities to extra superior software program options, permitting you to pinpoint the supply of any sluggishness. Completely different situations name for various instruments; figuring out when to make use of which methodology is essential to understanding your connection’s true capabilities.
Widespread Strategies for Measuring Obtain Latency
Correct measurement of obtain latency depends on numerous strategies. On-line velocity exams, usually discovered by way of easy internet searches, present fast and simple assessments. These instruments continuously make the most of the ping precept, measuring the time it takes for a packet of information to journey out of your laptop to a server and again. Subtle community monitoring software program affords extra detailed analyses, capturing metrics past primary latency, comparable to packet loss and jitter.
This granular stage of element permits a deeper understanding of the community’s efficiency traits. Moreover, devoted obtain managers usually incorporate latency measurement instruments into their person interface, offering real-time suggestions throughout file transfers.
Models of Measurement
The elemental unit for measuring obtain latency is the millisecond (ms). This unit, representing one-thousandth of a second, gives a exact approach to quantify the time it takes for information to traverse the community. Whereas seconds are used for broader measurements, milliseconds present the required precision for pinpointing delicate variations in latency. Understanding this granular stage of measurement is crucial for pinpointing efficiency bottlenecks.
Instruments and Software program for Measuring Obtain Latency
A plethora of instruments can be found to measure obtain latency. On-line velocity check web sites provide user-friendly interfaces for fast assessments. Devoted community monitoring software program gives detailed insights into community efficiency, together with latency. These instruments are essential for complete efficiency evaluation. Furthermore, some working programs embrace built-in instruments for primary latency checks, offering a easy place to begin for investigating community points.
Desk of Instruments for Measuring Obtain Latency
| Device | Professionals | Cons |
|---|---|---|
| On-line Velocity Take a look at Web sites (e.g., Ookla Speedtest) | Straightforward to make use of, available, gives a fast overview of latency | Restricted information, could not seize detailed community metrics, generally affected by location or server circumstances. |
| Community Monitoring Software program (e.g., Wireshark, SolarWinds Community Efficiency Monitor) | Detailed evaluation of community visitors, together with latency, packet loss, and jitter. | Steeper studying curve, requires technical experience, probably overwhelming for primary customers. |
| Devoted Obtain Managers (e.g., uTorrent, JDownloader) | Latency info displayed throughout file transfers, permitting real-time changes and troubleshooting. | Focuses on particular obtain duties, could not provide a complete view of general community efficiency. |
| Constructed-in Working System Instruments | Free and available, good for preliminary diagnostics | Restricted performance, usually lack superior options and detailed reviews |
Affect of Obtain Latency on Person Expertise
Obtain latency, that irritating delay between clicking a button and seeing the outcomes, considerably impacts person expertise throughout a variety of on-line actions. Think about ready for a video to buffer or a recreation to load – these delays can shortly flip a pleasing expertise right into a irritating one. This part delves into the multifaceted methods obtain latency impacts customers, from easy file downloads to advanced on-line interactions.Obtain latency acts like a hidden tax on person satisfaction.
Each second of delay diminishes the sensation of responsiveness and management, leaving customers with a way of sluggishness and inefficiency. That is very true for functions requiring near-instantaneous suggestions, like on-line gaming or real-time communication instruments.
Streaming Video
Obtain latency straight impacts the smoothness of streaming video. Excessive latency results in noticeable buffering and uneven playback, destroying the immersive viewing expertise. Take into consideration watching a stay sporting occasion, the place a 1-second delay could make the motion really feel prefer it’s taking place in gradual movement. Customers usually abandon a streaming session when latency constantly interferes with the viewing expertise.
A seamless, uninterrupted video stream is essential for person engagement. A delay of even a number of seconds can result in frustration, inflicting customers to hunt out options.
Downloading Massive Information
The influence of latency on massive file downloads is stark. Customers expertise a noticeable delay within the obtain progress, affecting their general satisfaction with the method. The longer the obtain takes, the extra customers could grow to be annoyed, main them to desert the obtain altogether. As an example, downloading a high-resolution picture or a big software program replace may be considerably impacted by latency.
The time spent ready for the obtain to finish can result in vital person dissatisfaction.
On-line Gaming
Latency in on-line gaming is a crucial issue affecting the gameplay expertise. A couple of milliseconds of delay can imply the distinction between profitable and dropping an important spherical, or a devastating influence on the general aggressive expertise. In fast-paced video games, even a small delay can result in mistimed actions, missed alternatives, and a irritating gaming expertise. Gamers expertise a disconnect from the sport, and the sensation of responsiveness is misplaced.
This disconnect may be very irritating, resulting in a major lower within the high quality of the gaming expertise.
Video Conferencing, What is an effective obtain latency
Latency in video conferencing functions can create a jarring expertise for members. Delayed video and audio can result in misunderstandings, awkward silences, and a way of disconnection. The lack to speak in real-time can result in frustration, as customers really feel they don’t seem to be absolutely a part of the dialog. Think about attempting to have a crucial assembly the place the members are continually experiencing delays of their audio or video.
File Sharing
Latency in file-sharing functions can considerably influence the person expertise, significantly when sharing massive recordsdata. Sluggish add and obtain speeds can result in frustration and abandonment of the sharing course of. The delay can create an unfulfilling person expertise. Take into consideration sharing a big challenge file with colleagues, the place a gradual switch fee could make collaboration troublesome and inefficient.
Perceived Responsiveness
Obtain latency straight impacts the perceived responsiveness of a system. Excessive latency results in a sense of sluggishness and lack of responsiveness, inflicting customers to understand the system as gradual and unresponsive. The time it takes for a system to answer person actions considerably influences the person expertise. Even seemingly minor delays can contribute to a sense of frustration and disconnect.
The influence is not only about velocity, but additionally in regards to the perceived velocity and responsiveness.
Components Influencing Obtain Latency: What Is A Good Obtain Latency
Obtain latency, the time it takes for a file to switch from a server to your machine, is a vital think about person expertise. Understanding the assorted forces shaping this important metric is essential to optimizing efficiency and making a seamless digital journey for customers. From the bodily infrastructure to the intricate protocols governing information transmission, quite a few parts contribute to the general obtain expertise.
Community Infrastructure’s Position
Community infrastructure, the bodily framework supporting information switch, performs a pivotal function in obtain latency. This encompasses all the things from the fiber optic cables snaking throughout continents to the routers and switches directing visitors. A strong and well-maintained community, with enough bandwidth and low congestion, usually ends in quicker downloads. Conversely, outdated or poorly maintained infrastructure can considerably hinder efficiency, inflicting delays and frustration.
Server Location and Distance
Server location and the geographical distance between the server and the person straight influence obtain latency. Information travels on the velocity of sunshine, however the distance it has to cowl provides appreciable time. A server situated geographically nearer to the person usually ends in decrease latency. It is a key issue for international customers; these in shut proximity to a server will expertise a lot quicker obtain speeds than these additional away.
Community Congestion
Community congestion, characterised by an amazing quantity of information packets competing for transmission channels, considerably impacts obtain latency. Think about a crowded freeway; the extra autos, the slower the visitors move. Equally, a community overloaded with information packets creates bottlenecks, slowing down the transmission of particular person packets. Peak hours or in style occasions usually exacerbate this problem, resulting in noticeable obtain delays.
Affect of Web Protocols
Web protocols, the algorithm governing information transmission, affect obtain latency in a number of methods. Completely different protocols deal with information packets in a different way, resulting in variations in effectivity. Protocols designed for optimum efficiency in high-bandwidth environments could not carry out as nicely in congested networks. The precise protocols used for transferring information and the effectivity of these protocols can tremendously influence latency.
As an example, optimized protocols usually cut back the overhead related to packet dealing with, resulting in decrease latency.
Affect of Completely different Community Components
| Community Issue | Affect on Obtain Latency |
|---|---|
| Community Infrastructure High quality | Excessive-quality infrastructure with enough bandwidth minimizes latency; poor infrastructure results in vital delays. |
| Server Location | Servers nearer to the person lead to decrease latency; larger distances enhance latency. |
| Community Congestion | Excessive congestion creates bottlenecks, growing latency; low congestion ends in quicker downloads. |
| Web Protocols | Optimized protocols with decrease overhead reduce latency; inefficient protocols can result in greater latency. |
Optimizing Obtain Latency
Obtain latency, that irritating lag between clicking a button and seeing the content material, impacts person expertise considerably. Velocity issues, and understanding the right way to optimize it’s key to a constructive on-line journey. Figuring out the right way to fine-tune obtain speeds and mitigate community points is essential for a easy digital expertise.Efficient optimization methods, significantly for particular use instances, are very important.
Whether or not it is a high-resolution picture, a big software program obtain, or a stay video stream, tailor-made approaches are important. Understanding the nuances of various community situations, from house Wi-Fi to international information facilities, helps to tailor optimization for optimum efficiency.
Methods for Particular Use Instances
Obtain speeds for numerous content material sorts require distinctive methods. Excessive-resolution photos, for instance, want optimized compression strategies to scale back file measurement with out sacrificing high quality. Equally, video streaming calls for environment friendly encoding and supply strategies. Massive software program installations profit from segmented downloads and resuming capabilities.
Optimizing Obtain Speeds
Environment friendly obtain speeds are essential for a constructive person expertise. Content material Supply Networks (CDNs) play a pivotal function on this. CDNs distribute content material throughout a community of servers, bringing it nearer to customers geographically. This dramatically reduces latency by serving content material from the server nearest to the person. Correctly configured CDNs can considerably enhance obtain speeds, making content material available no matter location.
Caching mechanisms additional optimize obtain speeds by storing continuously accessed content material domestically.
Mitigating Community Congestion
Community congestion is a typical wrongdoer behind gradual downloads. To mitigate its influence, take into account methods like prioritizing downloads, adjusting obtain schedules to keep away from peak hours, and using clever visitors administration strategies. These strategies can successfully cut back the influence of congestion on obtain latency, permitting customers to entry content material seamlessly.
Strategies for Minimizing Latency in Completely different Community Situations
Optimizing for various community situations is paramount. As an example, optimizing downloads on a cellular community requires completely different strategies than on a high-speed wired connection. Cellular networks usually have various bandwidth and latency traits. Adaptive obtain protocols that regulate to altering community circumstances are very important in these situations. Utilizing a CDN that helps cellular networks can be crucial.
Desk Evaluating Latency Optimization Methods
| Technique | Description | Effectiveness |
|---|---|---|
| Content material Supply Networks (CDNs) | Distribute content material throughout a community of servers nearer to customers. | Excessive – Reduces latency considerably, particularly for geographically dispersed customers. |
| Adaptive Obtain Protocols | Regulate to altering community circumstances throughout downloads. | Excessive – Improves reliability and velocity in unstable networks. |
| Prioritizing Downloads | Assign greater precedence to crucial downloads. | Medium – Can enhance efficiency in congested environments. |
| Optimized Compression Strategies | Cut back file measurement with out sacrificing high quality. | Excessive – Particularly essential for high-resolution photos and movies. |
Examples of Good and Unhealthy Obtain Latency
Obtain latency, that invisible time lag between clicking a button and seeing the outcomes, considerably impacts our digital experiences. Think about ready for a webpage to load, a video to buffer, or an app to reply. Understanding the spectrum of fine and unhealthy latency is essential for each builders and customers. A easy, responsive expertise is essential to satisfaction, whereas irritating delays can bitter even the perfect on-line interplay.Obtain latency will not be a one-size-fits-all problem.
The appropriate vary varies tremendously relying on the appliance and the person’s expectations. A easy picture obtain may tolerate a number of seconds of delay, however a stay video stream calls for near-instantaneous response.
Acceptable Obtain Latency Values
Completely different functions have various wants for obtain latency. A quick-loading web site goals for near-instantaneous response, whereas a big file obtain may tolerate a barely longer wait time. Contemplate these examples:
- Net searching: web site hundreds in beneath 2 seconds. Something over 5 seconds can really feel sluggish and irritating, probably driving customers away.
- Video streaming: Latency under 1 second is essential for a easy viewing expertise. Something over 2 seconds can result in noticeable buffering and a jerky video playback, ruining the viewing expertise.
- On-line gaming: Latency must be exceptionally low, usually measured in milliseconds. Even a number of milliseconds of delay can have an effect on gameplay, probably resulting in misplaced battles or irritating gameplay.
- Massive file downloads: For downloading massive recordsdata, a latency of some seconds per megabyte is suitable, however elements like community circumstances and server capability considerably affect the obtain velocity and, consequently, the latency.
Traits of a Good Obtain Latency Expertise
A constructive obtain latency expertise is characterised by responsiveness and seamlessness. Customers mustn’t discover any delays. Downloads ought to full shortly, with none noticeable pauses or interruptions. expertise interprets into effectivity and satisfaction.
Penalties of Poor Obtain Latency
Poor obtain latency results in a detrimental person expertise. Customers usually expertise frustration and dissatisfaction. This may vary from minor annoyances to vital detrimental impacts. Poor latency can result in misplaced gross sales, diminished person engagement, and finally, a broken status.
Significance of Obtain Latency in Completely different Use Instances
The significance of obtain latency differs considerably relying on the context. A gradual web site loading time can deter potential clients in an e-commerce state of affairs. In a stay video streaming surroundings, excessive latency can spoil your entire expertise for viewers.
Desk Contrasting Good and Unhealthy Obtain Latency Situations
| Situation | Good Latency | Unhealthy Latency | Affect |
|---|---|---|---|
| Net searching | <2 seconds | >5 seconds | Quick, responsive searching vs. gradual, irritating expertise |
| Video streaming | <1 second | >2 seconds | Clean playback vs. buffering and jerky playback |
| On-line gaming | Milliseconds | >10 milliseconds | Responsive gameplay vs. lag and misplaced battles |
| File obtain | Seconds per megabyte | Minutes per megabyte | Environment friendly obtain vs. extraordinarily gradual obtain |
Latency and Community Protocols
![Defining The Qualities Of A Good Friend [Infographic] - Venngage](https://i1.wp.com/venngage-wordpress.s3.amazonaws.com/uploads/2023/09/Qualities_Of_A_Good_Friend_Infographic-1024x791.png?w=700 "Defining The Qualities Of A Good Friend [Infographic] - Venngage")
The digital freeway, whereas seemingly seamless, is ruled by intricate guidelines and protocols. Understanding how these protocols influence obtain velocity is essential for optimizing your on-line expertise. Community protocols, just like the unsung heroes of information transmission, play a major function in figuring out how shortly your recordsdata arrive.Community protocols, basically units of guidelines for communication, decide how information packets are despatched and acquired.
Completely different protocols prioritize completely different facets of the switch – velocity versus reliability. This basic trade-off straight impacts latency, making a transparent understanding important for anybody trying to maximize their on-line expertise.
Affect of TCP on Obtain Latency
TCP, or Transmission Management Protocol, is famend for its reliability. It ensures each bit of information arrives intact, meticulously confirming receipt. This methodical strategy, whereas essential for error-free transfers, can generally result in barely greater latency. Think about a meticulous courier, double-checking each bundle earlier than transferring on, leading to a barely slower supply time however making certain the contents arrive unscathed.
That is the essence of TCP’s strategy. TCP’s acknowledgment mechanisms and retransmission of misplaced packets add a layer of overhead, which might enhance latency in sure conditions.
Affect of UDP on Obtain Latency
UDP, or Person Datagram Protocol, is the velocity demon of the digital world. It prioritizes velocity over reliability. Consider it as a supply service that sends packages with out ready for affirmation. Packages may get misplaced, or arrive out of order, however the velocity is unmatched. This attribute of UDP results in decrease latency, making it preferrred for real-time functions like on-line gaming or video streaming the place a slight delay may be detrimental to the person expertise.
Nevertheless, this lack of reliability means information loss can happen, impacting the integrity of the acquired information.
Comparability of TCP and UDP
| Function | TCP | UDP |
|---|---|---|
| Reliability | Excessive | Low |
| Latency | Increased | Decrease |
| Error Dealing with | Strong | Minimal |
| Functions | File downloads, internet searching | On-line gaming, video streaming |
This desk highlights the important thing variations between TCP and UDP, showcasing their contrasting approaches to information transmission. The selection between TCP and UDP relies upon closely on the precise wants of the appliance. If reliability is paramount, TCP is the popular alternative. If velocity is the overriding issue, UDP is the higher possibility, even with the potential for some information loss.
Contemplate a online game; you’d seemingly need the decrease latency of UDP, even when a number of pixels often go lacking.
Commerce-offs Between Velocity and Reliability
The connection between velocity and reliability is a basic trade-off in networking. A system prioritizing velocity usually sacrifices reliability, and vice-versa. A quick courier service may often lose packages, whereas a extremely dependable courier service will inevitably be slower. Understanding these trade-offs is essential for choosing the suitable protocol for a selected process. Completely different conditions demand completely different priorities.
A monetary transaction requires excessive reliability, whereas a online game stream prioritizes low latency. Selecting the proper protocol ensures the optimum steadiness between velocity and reliability for a given process.
Obtain Latency and Server-Facet Optimization
A easy on-line expertise hinges on swift downloads. This important facet usually will get ignored, however the server facet performs an important function in attaining fast supply. Optimizing server sources and configurations is paramount for minimizing latency and boosting person satisfaction. Understanding the methods employed by server directors can tremendously enhance your understanding of obtain efficiency.Server-side optimization is a crucial think about lowering obtain latency.
It is not simply in regards to the velocity of your web connection; it is about making certain the server can ship the requested information effectively. This includes cautious planning and execution on the server stage, impacting the time it takes for information to journey from the server to your machine. The server’s potential to reply shortly and ship the requested information in a well timed method is essential to attaining optimum obtain speeds.
Server {Hardware} Issues
Environment friendly server {hardware} is the inspiration of low latency. Selecting the best {hardware} ensures that requests are processed shortly and information is transferred easily. The velocity and capability of the processor, RAM, and onerous drives straight influence the server’s potential to deal with concurrent requests. Servers want to have the ability to deal with the amount of information being requested.
This requires sturdy {hardware} that may maintain excessive visitors with out slowing down.
Server Software program Optimization
Efficient server software program is crucial for managing information and processing requests. Environment friendly software program can considerably cut back latency by optimizing the info switch processes. Selecting the best working system, utility server, and database system can optimize useful resource utilization and streamline the supply of requested information. This ends in quicker responses to shopper requests and diminished latency.
Server-Facet Optimization Methods
Quite a lot of strategies can improve server efficiency and cut back obtain latency. These methods could make a major distinction in how shortly information is delivered.
- Content material Supply Networks (CDNs): CDNs distribute content material throughout a number of servers globally, bringing the info nearer to customers. This considerably reduces the gap information must journey, leading to quicker obtain instances. This strategy is especially efficient for international audiences.
- Caching Methods: Caching continuously accessed information on middleman servers reduces the load on the primary server and accelerates response instances. This reduces the quantity of information that must be transferred every time, leading to quicker supply.
- Compression Strategies: Compressing information earlier than transmission reduces the dimensions of the info transferred. This considerably accelerates obtain instances, particularly for big recordsdata. This may additionally cut back community visitors and bandwidth consumption.
- Load Balancing: Distributing incoming requests throughout a number of servers prevents overload on any single server. This ensures constant efficiency and reduces the chance of latency spikes. That is significantly essential for high-traffic web sites and functions.
Greatest Practices for Server Design
Implementing these practices throughout server design ensures optimum efficiency and minimizes latency. The design stage is essential in establishing a basis for quick and environment friendly supply.
- Environment friendly Code: Writing optimized code reduces processing time, resulting in decrease latency. Code effectivity is a major contributor to minimizing obtain latency.
- Database Optimization: Database queries needs to be optimized to attenuate the time required to retrieve information. Database queries are a crucial facet of internet functions, and optimizing them can considerably cut back latency.
- {Hardware} Scalability: Selecting scalable {hardware} ensures the server can deal with growing visitors with out vital efficiency degradation. Scalability is essential for long-term efficiency.
Server Optimization Strategies Desk
This desk summarizes numerous server-side optimization strategies and their advantages.
| Method | Profit |
|---|---|
| Content material Supply Networks (CDNs) | Reduces obtain time by distributing content material globally |
| Caching | Decreases server load and accelerates responses |
| Compression | Reduces information measurement, leading to quicker downloads |
| Load Balancing | Ensures constant efficiency and prevents overload |
| Environment friendly Code | Reduces processing time and improves responsiveness |
| Database Optimization | Minimizes information retrieval time |
| Scalable {Hardware} | Handles growing visitors with out efficiency degradation |
