千兆网下载跑不满，真是你的问题？Steam下载速度怎么这么快？【柴知道】

Summary

This video explores the nuances of internet speed, addressing the common misconception that upgrading to a gigabit connection guarantees superior performance. It explains the difference between download and upload speeds, the impact of bandwidth costs on service providers' decisions to throttle speeds, and the role of CDN in enhancing download speeds. The script also delves into P2P technology and how Steam leverages it for fast game downloads. It concludes with practical advice on whether one should opt for a gigabit internet plan, suggesting it may be unnecessary for most casual users.

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Q & A

What is the difference between the bandwidth promised by a 'gigabit internet' plan and the actual download speeds experienced by the user?

The 'gigabit internet' plan promises a bandwidth of 1000 Mbps, which theoretically translates to a download speed of 125 MB/s. However, due to overhead from protocols and other data, the actual usable speed is around 118 MB/s. But the user experiences no significant change in speed for regular internet activities because many websites and services limit their upload speeds, which affects download speeds for users.

Why do websites and service providers limit upload speeds, and how does it affect the user experience?

Websites and service providers limit upload speeds due to the high cost of upload bandwidth. Uploading data is more expensive than downloading because most users primarily consume data rather than upload it. This limitation can result in slower download speeds for users, even if they have a high-speed internet plan.

How does the cost difference between upload and download bandwidth affect internet service providers' business strategies?

The cost difference between upload and download bandwidth leads service providers to prioritize selling download bandwidth to consumers and upload bandwidth to business users who can afford it. This results in asymmetrical upload and download speeds for consumers, with the 'gigabit' speed referring only to downloads, not uploads.

What is the role of CDN (Content Delivery Network) in enhancing download speeds, and how does Steam utilize it?

CDNs are interconnected server systems that store frequently accessed content in different locations to reduce latency and improve download speeds. Steam uses CDNs extensively by deploying servers globally, including in China, which allows it to provide high-speed, stable downloads that can approach the theoretical limits of a user's internet plan.

How does the P2P (Peer-to-Peer) network model differ from traditional client-server models in terms of bandwidth usage?

In a P2P network, each device acts as both a client and a server, sharing and downloading content directly from other devices. This model can potentially maximize the use of available upload bandwidth from multiple sources, leading to faster download speeds for popular resources compared to traditional models where bandwidth is limited by the server's upload capacity.

What are the technical and commercial reasons behind the限速 (speed limiting) practices by websites and how does it impact the user?

Technically,限速 is practiced to manage and control the flow of data to prevent server overload. Commercially, it's a cost-saving measure to reduce expenses on bandwidth, especially for upload-intensive tasks. For users, this can result in slower download speeds, regardless of their subscribed internet plan's capacity.

How does the PCDN (Peer-to-CDN) technology work, and why are some internet service providers against it?

PCDN technology utilizes a user's upload bandwidth to distribute content to nearby users, effectively turning their devices into part of a CDN. This helps content providers save on bandwidth costs. However, some ISPs oppose it because it reduces their potential revenue from selling bandwidth and can increase the load on their networks without additional compensation.

What is the significance of the 'Mbps' and 'MB/s' units in the context of internet speed, and how are they related?

Mbps (Megabits per second) and MB/s (Megabytes per second) are units of data transfer rate. One byte (B) equals eight bits (b), so 1 Mbps is equivalent to 0.125 MB/s. The script explains that a 'gigabit internet' plan theoretically offers a speed of 125 MB/s, considering the conversion and overhead.

Why might a user not see a significant difference in their internet experience after upgrading to a gigabit internet plan?

A user might not see a significant difference because many websites and services limit their upload speeds, which in turn caps the download speeds for users. Additionally, the user's hardware and the distance from the data source can also limit the perceived speed improvements.

What are some strategies that content providers use to reduce bandwidth costs, and how do these affect the user's download experience?

Content providers may use strategies such as upgrading to more efficient video codecs like H.265 or AV1 to reduce file sizes, or they may implement限速 to directly limit download speeds. These strategies can lead to slower download experiences for users, especially if they are not aware of the underlying limitations.