High CPU usage
High device CPU usage
The tooltip displays the CPU usage on the device during a time interval, when the overall CPU usage is above 70%. The tooltip appears in two forms:
- When multiple applications are the cause of the high CPU load in the device and none is specially responsible for it, then the tooltip only gives a figure of the total CPU usage.
- When a few particular applications have a significant impact in the CPU load, the tooltip details these applications and their CPU usage per thread (this is different from the overall CPU usage, see explanation in the tooltip below), in addition to the overall CPU usage in the device.
The Collector takes a CPU load sample every 30 seconds and reports them every 5 minutes. To report high CPU usage, two or more consecutive samples must exceed 70% of CPU usage. The reported value corresponds to the average value of the samples above 70%.
High application CPU usage
The tooltip displays a list of the processes (and their corresponding application) that consumed more than 50% of the CPU processing power per thread (40% for the system process) for at least 30 seconds during the selected time interval. Processes are ordered in the list by their contribution to the CPU load from the most to the least demanding.
A 100% usage corresponds to the capacity of a single-core single-threaded CPU. You can get more than 100% usage in CPUs with multi-core or hyper-threading technologies:
- For each additional physical core in the CPU you get 100% more processing power. That is, the capacity of a dual-core CPU is 200%, for a quad-core is 400%, for an hex-core is 600%, and so on.
- If the CPU uses hyper-threading technology, the processing power of each physical core is doubled. A hyper-threaded dual-core CPU yields thus 400% capacity, a quad-core 800%, a hex-core 1200%, and so forth.
Note that this way of measuring is different from that of high CPU on the device, where the overall capacity of a CPU is 100%, regardless of the number of cores and threads in the CPU. For this reason, the bottom of the tooltip displays the capacity of the CPU in terms of hardware threads, which can be (and it usually is) bigger than 100%.
The tooltip displays the usage of physical memory when more than 70% of the total physical memory is in use for at least 5 minutes.
In its lower part, the tooltip lists the top five processes that consume the most memory. Only processes that take more than 1% of the total memory are listed.
High IO throughput
The warning shows up when IO operations exchange information at a rate higher than 20 MB/s during at least 30 seconds.
The total IO throughput includes all the bytes transferred during read, write or any other kind of IO operation performed on either real or virtual peripherals, such as hard disks, flash drives, network controllers, keyboards, mice, etc.
High page faults
The warning appears when the device generates more than 5000 page faults per second in memory accesses during at least 5 minutes.