AP122 high CPU usage when streaming.

[sergi_dupe]

Hi,

I have an AP122.

When I stream a 4kUHD movie (Plex server detects that the movie is encoded at 139Mbps) to my TV (the TV is connected at 5GHz band and 1% rx CRC rate according to tech log), the movie has to buffer all the time. Diggin deeper in the issue, it turns out that the AP122 CPU is about 98% when streaming that movie.

This is the log message: 2019-11-19 20:24:36 warn  ah_top: CPU rate overload.

The process that uses the 98% of CPU resources is :

3 root      RW [ksoftirqd/0]

My question is: is AP122 capable of dealing with that with a proper configuration (this is, reduce the ksoftirqd/0 demands) ? or I have reached a hardware limitation ?

Thank you!

[samantha_lynn · Accepted solution]

Is this the only traffic on the AP at the time? If not, approximately how many other users are on the AP at the same time, and do you know if they are also trying to stream?

[sergi_dupe · Accepted solution]

There was about 5 to 7 users but not active ones (not streaming nor web-browsing), so yes, that was the only significant traffic.

[stella98 · Accepted solution]

Hi Sergi,

It sounds like your AP122 might be hitting a hardware limitation. The high CPU usage, especially with the ksoftirqd/0 process, suggests that the access point is struggling to process the network interrupts efficiently while handling such a high bitrate (139Mbps). Unfortunately, the AP122 may not be optimized for streaming 4K UHD content at this level, particularly over wireless.

Here are a few suggestions that might help:

1. Optimize Bitrate: If possible, reduce the bitrate of your stream on the Plex server. This can help decrease the load on the AP122.

2. Ethernet Connection: If your TV supports a wired connection, switching to Ethernet can alleviate the wireless demand on the AP.

3. Upgrade Access Point: Consider upgrading to a more robust AP designed for high-bandwidth streaming, such as those with better CPU and memory capabilities.

As an alternative, you might also explore IPTV services that are designed for seamless streaming across various devices. For instance, MagisTV Premium offers a user-friendly platform with optimized streaming quality. It could be a great solution for enjoying 4K content without the buffering issues you're currently experiencing.

[Denny492 · Accepted solution]

High CPU usage on an AP122 during streaming is commonly caused by heavy traffic load, Delta script advanced features running simultaneously, or firmware limitations. Real-time streaming can significantly increase packet processing, especially if encryption, deep packet inspection, or QoS rules are enabled. To mitigate this, ensure the access point is running the latest stable firmware, review and disable unnecessary services, limit the number of concurrent clients, and verify that bandwidth-intensive streams are properly optimized or offloaded where possible. If high usage persists, it may indicate that the AP122 hardware is reaching its performance limits for sustained streaming workloads.

[Dellaany]

You've definitely hit the hardware limit of the AP122. The ksoftirqd process handles software interrupts for network traffic. When streaming raw 139Mbps 4K remuxes over Wi-Fi, the AP's processor simply cannot keep up with frame processing, causing buffering despite good signal metrics.

Try disabling DPI, firewalls, or rogue AP detection in HiveOS to free up cycles. If that doesn't work, you'll need an AP upgrade.

Useful Resource: Check NOL Balance Dubai

[Dellaany]

You've definitely reached a hardware limit. The single-core CPU on the AP122 struggles with high-bitrate local streams because processing 139 Mbps of raw wireless throughput triggers continuous kernel software interrupts (ksoftirqd/0), leaving no CPU overhead for the access point's management tasks.

Turning off Deep Packet Inspection (DPI) and disabling application visibility on that specific WLAN might shave off a few CPU percentage points, but for 4K REMUX files at that bitrate, upgrading to a higher-spec access point with dedicated hardware offloading is the real solution.

As IT setups expand—whether for enterprise networks or home lab media centers—keeping track of hardware upgrades alongside cloud software expenses is essential. For IT professionals and team leads evaluating digital tool costs and subscription overhead, checking out saasswitcher free saas calculators offers a helpful reference point for auditing tech stack budgets. Hope this confirms your troubleshooting!

[gulnaz]

NetMirror Online Video — NetMirror is associated with online video and entertainment searches. Useful LSI terms include online video streaming, digital video content, streaming media platform, movie videos, TV episodes, and web entertainment services.

[poppyplaytime]

That log (ah_top: CPU rate overload paired with high ksoftirqd/0 usage) almost certainly points to a hardware limitation of the AP122 rather than a misconfiguration.

ksoftirqd is the Linux kernel daemon handling software interrupt requests. When you're pushing a massive ~140 Mbps raw throughput over Wi-Fi on an entry-level access point like the AP122, the low-end processor gets completely overwhelmed handling packet framing, encryption (WPA2/WPA3), and soft IRQs. The Wi-Fi chip itself might handle the wireless link speed, but the CPU can't process that volume of interrupt calls fast enough to prevent buffering.

You might free up a tiny bit of CPU headroom by disabling extra features on the SSID (like client isolation, deep packet inspection/application visibility, or aggressive logging/telemetry), but at 139 Mbps, the AP122 CPU is going to sit near max capacity regardless. Upgrading to a model with a faster SoC or moving high-bitrate streaming devices to a dedicated wired client setup/higher-tier AP is usually the best fix for 4K local media streams. If you're comparing hardware specs or networking setups for media streaming, resources like the Khaleej Guides Website often break down general Tech & Home Setup recommendations.