104 Modems to Avoid: The Ultimate PDF List of Unreliable Modems [2026 Update]

If you are experiencing issues with your internet connectivity like frequent disconnects, lag spikes or slow speeds that are intermittent, the underlying issue could very well be the chipset in your cable modem. Specifically, modems using Puma 6/7 chipsets—originally developed by Intel and now part of MaxLinear’s platform—have been known to cause performance and stability problems. MaxLinear announced the next‑gen Puma 8 (DOCSIS 4.0) in 2023, and retail DOCSIS 4.0 customer premises equipment began appearing through 2024–2025, but legacy Puma 6/7 units remain widely deployed.

In this comprehensive guide, we cover what matters most: the complete list of affected models (with a downloadable PDF), the defects explained, how to identify Puma‑based units reliably, the legal backdrop, and your options going forward. If you just want the list, it’s below under Complete List of Unreliable Modems to Avoid.

Complete List of Unreliable Modems to Avoid Purchasing or Renting

Here is a frequently updated list of cable modems documented or confirmed to be using Puma 6 or Puma 7 chipsets. Use it to cross‑check your model number before buying or renting. The downloadable PDF mirrors this table.

Avoid purchasing or renting the models below:

What is the Puma Chipset Defect?

Puma chipsets are built into the modems offered by many popular brands like Arris, Netgear, Linksys and others. The platform lineage is Intel (Puma 5/6/7) and, since 2020, MaxLinear (Puma, including Puma 8 for DOCSIS 4.0). The core issue reported with Puma 6/7 is a hardware/firmware interaction under load that triggers latency spikes and jitter. In real‑world use, this can manifest as the following:

Frequent disconnects and modem reboots
High spikes in latency leading to lag
Severe network jitter (variable latency)
Slow page loads and buffering issues
Packet loss and connectivity drops during gaming or video calls

The main culprit is that the chipset’s processing path can struggle to handle certain traffic patterns predictably. Essentially, time‑sensitive packets are not always prioritized, and periodic maintenance tasks can consume resources, leading to delays and congestion.

This results in highly variable speeds and ping times, making activities like online gaming, video streaming and even web browsing a frustrating experience.

Initially highlighted by gamers complaining of lag spikes, the Puma 6 defect gained widespread attention in 2016 and became the subject of litigation and extensive community testing. Firmware mitigations reduced some symptoms, but issues were also reported on Puma 5 and 7 in later disclosures.

Why are Puma 6 and Puma 7 Modems Still Being Sold?

Despite awareness of the issue, many cable ISPs continued supplying customers with modems containing Puma 6 or Puma 7 chipsets. While firmware updates mitigated some latency and jitter, they did not fully resolve all behaviors, and separate denial‑of‑service vectors were documented. Inventory costs, rental revenue, and mixed user experiences also slowed full replacement.

So should you avoid Puma 6 and 7 modems? While not everyone encounters severe problems, the risk remains. And there are affordable, reliable alternatives without these chipsets.

How to Identify an Intel Puma Modem?

Here are some tips for identifying modems with Puma chipsets accurately:

• Packaging/labels – Retail boxes rarely disclose the SoC used, and you won’t usually see “Puma 6/7” branding or an Intel logo that identifies the chipset.
• Cross‑check sources – Rely on vetted model lists (like the one above), OEM knowledge‑base articles, FCC filings/teardowns, and ISP approved‑device lists to confirm whether a model is Puma‑based.
• Model numbers – Refer to the list below of affected modem models by major brands.

How to Check if Your Modem Uses Intel Puma

If you can’t identify the chipset from model numbers, packaging or manuals, here are some ways to check:

• Command prompt – Access your modem administration console and check what hardware is listed under the model name
• Contact ISP – Your Internet provider can look up the model and confirm the chipset
• Chat support – Initiate a chat session with the modem manufacturer and ask what chipset it uses

The Legal Implications

The widespread issues led to multiple legal actions. In the SB6190 matter, a federal court granted partial class certification in 2018 for California purchasers, with subsequent proceedings and related actions involving multiple vendors. Case status and remedies vary; verify current details before assuming eligibility for compensation.

Overall, the litigation signals that companies selling products with known defects can face legal repercussions. For affected customers, documenting your experience can assist with future consumer actions.

Should You Keep Using a Puma Modem?

Puma‑based modems don’t impact every customer. Light internet users may never notice connectivity problems or may attribute them to regular ISP issues. But the risk remains for instability which can hamper work productivity or leisure online.

For equipment owners, replacing your modem is recommended. Renters can request a swap from their provider. Opt for a reliable Broadcom‑based DOCSIS modem as the primary non‑Puma alternative, and verify the chipset with the manufacturer’s documentation.

If upgrading isn’t viable, try these troubleshooting steps:

• If upstream instability coincides with OFDMA rollouts, escalate to your ISP’s engineering team for diagnostics. OFDMA provisioning is ISP‑managed and is required for higher upload tiers; disabling it may temporarily stabilize some links but can reduce upload speeds.
• Enable bridge mode to bypass the modem’s router
• Use wired connections instead of WiFi where possible

Avoiding latency and stability issues should be the priority. The Puma defect is hardware‑linked, so software updates provide only partial fixes.

Top 3 Puma-Free Modem Recommendations

Here are some excellent and affordable Puma‑free alternatives to consider for a fast and reliable connection:

1

ARRIS SURFboard SB8200 DOCSIS 3.1 Cable Modem , Approved for Comcast Xfinity, Cox, Charter Spectrum, & more , Two 1 Gbps Ports , 1 Gbps Max Internet Speeds ,...

9.9

View Latest Price

Amazon.com

2

NETGEAR Nighthawk Multi-Gig Cable Modem (CM2000) - Compatible With All Cable Providers Incl. Xfinity, Spectrum, Cox - For Cable Plans up to 2.5Gbps - DOCSIS 3.1

9.3

View Latest Price

Amazon.com

3

Motorola MB8600 DOCSIS 3.1 Cable Modem - Approved for Comcast Xfinity, Cox, and Charter Spectrum, Supports Cable Plans up to 1000 Mbps | 1 Gbps Ethernet Port

9.3

View Latest Price

Amazon.com

1. Motorola 8600

The Motorola 8600 uses a Broadcom chipset that avoids Puma‑related problems. It’s a DOCSIS 3.1 modem with link aggregation on ports 1–2; practical service tiers top out around 1 Gbps per port or up to ~2 Gbps aggregate with LAG on supported plans and routers.

2. Netgear CM2000

Another modem praised for stability is the Netgear CM2000 with its Broadcom chipset and a 2.5GbE port. It supports multi‑gig plans up to 2.5 Gbps where available.

3. ARRIS Surfboard SB8200

If you want an Arris modem without Puma, check out the ARRIS Surfboard SB8200 and its reliable Broadcom chipset. It has two 1GbE ports with Link Aggregation and can deliver up to ~2 Gbps aggregate with a compatible router and ISP plan.

Conclusion

In closing, all internet subscribers deserve a modem free of hardware flaws that hamper connectivity. Avoid using or renting devices with Puma 6 or Puma 7 chipsets that come with instability risks, and be aware that the Puma platform is now owned by MaxLinear with Puma 8 powering early DOCSIS 4.0 devices.

Check your equipment against model numbers listed and consider better alternatives recommended if you face frequent lag, packet loss or slow speeds. The goal is consistent, smooth performance—prefer hardware that’s proven to deliver it.

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Afroz Ahmad

I'm Afroz, a Network Engineer and CCIE with more than 18 years of experience in Computer Networking, Data Centers, Telecom, Internet Services and ISPs. Currently, I work as a Network Designer for a leading ISP equipment vendor. I share my expertise through my blog and courses, aiming to share my knowledge and simplify complex networking concepts for both beginners and experienced professionals.

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