Intel Puma 6 chipset for gigabit broadband modems is causing horrific latency spikes

Intel said it's working on a fix for the Puma 6, a SoC found in numerous DOCSIS 3.0 gigabit broadband modems. The news comes after the discovery of huge latency spikes and packet loss issues with modems equipped with the Puma 6.

As The Register reports, the issue is caused by a high-priority maintenance task that runs every couple of seconds or so and clogs the x86 CPU in the modem. This results in latency spikes of over 200ms and, over time, packet loss that approaches the 6 percent mark.

"I excitedly swapped out my Arris SB1683 Broadcom modem for the new SB6190 Intel one expecting gigabit performance and immediately noticed slower webpage loads," he told The Register. "During first-person gaming, I was getting killed way more often for no apparent reason. I looked at an eight-year graph of latency from my home logs, and was horrified. Swapping back to my SB6183 solved all the issues."

This problem has been snowballing over the past year or so, ever since Puma 6-powered modems started shipping in large numbers, but has mostly stayed under the radar. In the past few months, though, the number of people with ultra-fast lines, and new top-end modems to use them, has grown, blowing the lid on Intel's programming blunder.

Intel promises a firmware update is on the way, a beta test of the fix is currently in progress. ISPs will be able to automatically push the new firmware to their Internet subscribers.