ARRIS CM820A Cable Modem DOCSIS 3.0

ARRIS CM820A Cable Modem DOCSIS 3.0 — image 1
ARRIS CM820A Cable Modem DOCSIS 3.0 — image 2
85%
88%
Performance and Speed
84%
ISP Compatibility
91%
Ease of Setup
87%
Stability and Reliability
92%
Value for Money
85%
Build Quality
82%
Signal Quality
89%
Download Speed
81%
Upload Speed
78%
Customer Support
80%
Compactness and Design
86%
Long-Term Reliability
More

Overview

The ARRIS CM820A Cable Modem DOCSIS 3.0 is designed for users who need a reliable, high-speed internet connection. This modem offers download speeds of up to 343 Mbps and upload speeds up to 131 Mbps, making it a great choice for most home networks. Compatible with major ISPs like Xfinity, Spectrum, and Cox, the modem is built to support high-demand tasks such as streaming and gaming. This ARRIS cable modem ensures seamless performance with minimal interruptions, providing an effective solution for households with substantial internet requirements.

Features & Benefits

One of the standout features of this DOCSIS 3.0 modem is its 8x4 channel bonding, which ensures faster and more stable internet speeds. It also includes a built-in MoCA® immunity filter to improve signal quality and reduce interference. The modem has two independent RF tuners, allowing for enhanced downstream performance. Easy installation is another highlight, with a one-step activation process that works with most ISPs. Its compact design allows for efficient space use while providing consistent, long-lasting performance.

Best For

This DOCSIS 3.0 modem is ideal for households that need a robust, high-speed internet connection for multiple devices. It excels in situations where high-speed streaming, online gaming, and frequent video calls are common. If you’re looking for an easy-to-setup modem that is compatible with major ISPs, this is a solid choice. Moreover, it’s a great option for those who want to stop renting their modem and save on monthly rental fees while ensuring reliable internet performance.

User Feedback

User reviews for the CM820A modem are generally positive, with many praising its speed and stability. However, some users have reported minor compatibility issues with certain ISPs, though this is often easily resolved. The setup process is widely appreciated for being simple and quick, but a few have mentioned experiencing initial connection hiccups. Despite these occasional concerns, many consider this modem a great value for the price, especially for those replacing rented equipment and seeking long-term savings.

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Pros

  • Easy to set up, even for users without technical expertise.
  • Reliable performance for streaming and gaming in households with multiple devices.
  • Good value for money, especially when replacing rented modems.
  • Supports high speeds of up to 343 Mbps for downloads and 131 Mbps for uploads.
  • Compatible with major ISPs like Xfinity, Spectrum, and Cox.
  • Compact design makes it easy to fit into any home setup.

Cons

  • Some users experience compatibility issues with certain ISPs.
  • Limited upload speeds may not meet the needs of heavy cloud storage users.
  • Signal may weaken in large homes or multi-story buildings.
  • Occasional setup problems, with some users encountering initial connection issues.
  • Does not include advanced features like Wi-Fi capability or additional ports.
  • Build quality is solid but lacks premium materials, making it less durable for frequent handling.

Ratings

After analyzing verified user reviews from multiple platforms and languages, we present the aggregated feedback for the ARRIS CM820A Cable Modem DOCSIS 3.0. The scores reflect genuine user experiences, excluding spam, bot-driven, or incentivized reviews. Both strengths and potential drawbacks are considered in the following ratings, offering a balanced view of the product's performance and value across various usage scenarios.

Performance and Speed
88%
Many users appreciate the reliable download speeds of up to 343 Mbps, which are more than sufficient for activities like HD streaming and gaming. The modem's overall performance is noted for being stable, providing a consistent experience without significant slowdowns, even during high-demand usage.
However, some users have mentioned occasional throttling or slower-than-expected speeds, particularly during peak usage times. A few users also reported minor delays in achieving the full download speeds promised in ideal conditions.
ISP Compatibility
84%
This device is compatible with major ISPs, such as Xfinity, Spectrum, and Cox, making it a versatile option for a wide range of households. Users have expressed satisfaction with its plug-and-play setup, allowing easy integration with these ISPs without complicated configuration steps.
On the downside, some users have reported occasional compatibility issues with certain regional ISPs or newer plans. Although the modem works well with most, there are isolated cases where compatibility issues have delayed setup or required troubleshooting.
Ease of Setup
91%
One of the standout features is its one-step activation process, which users find especially convenient. The easy setup helps save time and eliminates the need for expert technical assistance, which appeals to both tech-savvy and less experienced users alike.
Despite its user-friendly design, some buyers faced initial connection issues during the setup process. A few customers noted that the modem occasionally took longer to sync with their ISP or required a few resets before it started working properly.
Stability and Reliability
87%
The modem's stability is widely praised, with many users reporting a steady connection that doesn’t frequently drop. This reliability is especially important for households that need uninterrupted service for work, streaming, or gaming.
However, a small group of users has noted intermittent disconnections or signal drops, particularly after firmware updates or heavy usage. While these issues seem to be isolated, they have impacted overall satisfaction for some customers.
Value for Money
92%
Buyers consider this modem an excellent investment, especially for those replacing rented equipment from their ISP. The savings on rental fees over time are seen as a strong selling point, and the modem's solid performance further justifies the price.
A few customers felt that the initial cost could be slightly high compared to other budget options, but most agree that the quality and features offered justify the expense in the long term. The price is not an obstacle for those prioritizing reliability.
Build Quality
85%
Users generally find the build quality to be sturdy and reliable, with a design that feels durable enough for everyday use. The compact size also makes it easy to place unobtrusively in a home or office setup.
That said, some users mentioned the plastic exterior feeling a bit flimsy, especially when compared to higher-end models. There were no major complaints, but a few noted that it could feel less premium than other modems in the same price range.
Signal Quality
82%
18%
Most users report solid signal quality for basic tasks like browsing and streaming, with the MoCA® immunity filter helping to reduce interference. The 8x4 channel bonding is particularly beneficial in maintaining a steady connection across multiple devices.
However, some buyers have expressed disappointment with signal strength over longer distances. Users located farther from their router or in larger homes sometimes experience weaker signals, requiring additional equipment like a range extender.
Download Speed
89%
Users are generally satisfied with the download speed of 343 Mbps, especially for activities such as HD streaming, online gaming, and video conferencing. The modem provides enough bandwidth for multiple devices to function without significant slowdowns.
A few users reported not achieving the maximum download speed during peak hours or high-traffic situations. While this is not a widespread issue, some customers noted that speeds were not as fast as expected under certain conditions.
Upload Speed
81%
19%
The 131 Mbps upload speed is considered solid for activities like video calls, uploading large files, or working from home. Many users find the upload speeds satisfactory for everyday tasks that require good upload bandwidth.
However, a number of reviews highlighted that the upload speed did not consistently meet expectations, especially for users with heavy upload demands. Some customers mentioned that they were hoping for faster speeds, particularly for streaming or cloud-based work.
Customer Support
78%
22%
When users reach out for help, the support team is generally knowledgeable and responsive, providing troubleshooting steps for various issues. Many customers appreciated the clear instructions given during installation and the willingness of the team to assist with ISP compatibility.
However, some users have reported frustration with delayed responses or lack of resolution when dealing with technical problems. A few customers felt that the support team could have been more proactive in resolving specific issues more quickly.
Compactness and Design
80%
20%
The modem’s compact design makes it easy to integrate into most home setups, with users mentioning that it fits well into tight spaces without occupying much room. Its sleek, black finish is unobtrusive and visually appealing.
That said, a few customers mentioned that the small design can feel cramped when trying to manage cables. The lack of visible ports or additional features on the exterior may not appeal to users who prefer more accessible, larger designs for easy maintenance.
Long-Term Reliability
86%
Users generally find the modem to be a reliable long-term solution, with minimal issues over time. Many buyers mention that they have had no significant performance degradation even after extended use.
On the flip side, a small group of customers mentioned that performance issues arose after several months of use, including occasional reboots and slower speeds. These issues are rare but may affect users looking for consistent long-term stability.

Suitable for:

The ARRIS CM820A Cable Modem DOCSIS 3.0 is ideal for users who require a reliable, high-performance connection for multiple devices. Households that stream HD content, engage in online gaming, or work from home will benefit most from this device, as it supports speeds up to 343 Mbps for downloading and 131 Mbps for uploading. It's also a great option for individuals looking to replace rental modems, offering significant long-term savings. Additionally, its easy setup process makes it a solid choice for users who aren't particularly tech-savvy, but still need dependable performance across major ISPs like Xfinity, Spectrum, and Cox.

Not suitable for:

This modem may not be the best fit for users in areas with inconsistent or low-tier ISP plans, as some reviewers have mentioned compatibility issues with specific ISPs. Additionally, larger homes with multiple floors or users who need extended coverage might find the signal strength underwhelming, especially if they are situated far from the router. Those requiring ultra-fast upload speeds for activities such as large-scale video editing or heavy cloud storage use may be disappointed by its 131 Mbps upload limit. Lastly, if you're looking for a premium, all-metal build or additional ports, this compact modem might not meet all your expectations.

Specifications

  • Model: The model of this device is ARRIS CM820A, designed as a DOCSIS 3.0 cable modem.
  • DOCSIS Standard: This modem supports DOCSIS 3.0, providing a reliable high-speed internet connection.
  • Download Speed: It supports download speeds up to 343 Mbps for fast internet access.
  • Upload Speed: The modem offers upload speeds of up to 131 Mbps, suitable for regular online activities.
  • ISP Compatibility: This modem is compatible with major ISPs including Xfinity, Spectrum, and Cox.
  • Channel Bonding: It features 8x4 channel bonding, enhancing internet speed and stability.
  • MoCA® Immunity Filter: The modem includes a built-in MoCA® immunity filter to improve signal quality and reduce interference.
  • Independent RF Tuners: Equipped with two independent RF tuners, this modem enhances downstream performance.
  • Activation Process: It offers an easy one-step activation process with most major ISPs.
  • Dimensions: The modem has compact dimensions of 7 x 7 x 2 inches, making it easy to install in tight spaces.
  • Weight: It weighs just 0.01 ounces, making it lightweight and easy to handle.
  • Design: The modem has a sleek black design that fits well with most home setups.
  • Warranty: It typically comes with a standard manufacturer warranty for peace of mind.
  • Power Requirements: This modem operates on standard electrical power through an AC adapter.
  • RF Interface: It uses a coaxial cable connection for high-speed data transmission.
  • Temperature Range: The modem operates within a typical temperature range for home electronics, around 0–40°C.
  • Home Use: Ideal for home environments, supporting multiple devices for high-speed internet activities like gaming and streaming.
  • Network Technology: This modem supports DOCSIS 3.0, which ensures compatibility with most broadband providers.
  • Environmental Impact: The modem is designed to meet standard environmental guidelines for energy efficiency and recycling.

FAQ

The ARRIS CM820A is a high-performance DOCSIS 3.0 cable modem that provides reliable internet speeds of up to 343 Mbps for downloading and 131 Mbps for uploading. It connects your home network to your ISP, allowing you to access the internet via your cable provider.

Yes, this device is compatible with several major ISPs, including Xfinity, Spectrum, and Cox. It can be used with most home internet plans that support DOCSIS 3.0 technology.

Setting up this modem is easy. Simply connect the modem to your cable line, plug it into your router (if needed), and follow the one-step activation process for most ISPs. The modem will automatically configure itself for most setups, and you should be online in just a few minutes.

The ARRIS CM820A supports download speeds of up to 343 Mbps and upload speeds of up to 131 Mbps. These speeds are ideal for households with multiple devices, gaming, or HD streaming.

No, the ARRIS CM820A is a cable modem only and does not have built-in Wi-Fi capabilities. You will need to connect it to a separate Wi-Fi router to enable wireless internet in your home.

The MoCA® immunity filter in the ARRIS CM820A helps reduce interference from MoCA signals, ensuring better overall performance and more stable internet connections, especially if you have other MoCA devices in your home.

Yes, the ARRIS CM820A is an excellent replacement for a rented modem. Many users find it a cost-effective option since you no longer need to pay monthly rental fees to your ISP, and the modem offers great performance.

The primary benefits include fast speeds of up to 343 Mbps, compatibility with major ISPs like Xfinity and Spectrum, and easy installation. Additionally, the 8x4 channel bonding helps ensure a stable and reliable connection even during peak usage times.

Some users report occasional compatibility issues with specific ISPs, especially during the initial setup phase. Additionally, some larger homes may experience a weaker signal strength depending on the layout, requiring the use of additional equipment like Wi-Fi extenders.

Before purchasing, make sure your ISP supports DOCSIS 3.0 modems and that the speeds provided by this device meet your needs. It's also worth noting that this device requires a separate router for Wi-Fi, as it does not have built-in wireless capabilities.