diff --git a/wiki/advanced/zigzag-download-pattern.md b/wiki/advanced/zigzag-download-pattern.md new file mode 100644 index 0000000..460864e --- /dev/null +++ b/wiki/advanced/zigzag-download-pattern.md @@ -0,0 +1,35 @@ + # Zigzag download speed pattern + +## Sympton + +SABnzbd can show a zigzag download pattern like in the screenshot: + +image + +## Cause + +This is caused by a disk that is slower than the Internet newsserver download speed. + +Easy check: after downloading and seeing the pattern, in SABnzbd's upper right corner, click on the wrench symbol ("Status and interface options"), +then click on first tab Status. Check if you see "**Download speed limited by Disk speed** (...x)". If that line is there, it's proof your disk is the bottleneck. + +Then: in the same window, and there click on the Refresh Circled Arrow. After 10 seconds, in the lower part you will see the hardware performance and Internet speed. + +Example of a low spec machine (slow disk for Complete folder, low pystone value): + +image + + +## Explanation: +1. The first downloaded parts are cached into RAM, which is fast. +2. In the background, SABnzbd & OS is writing from RAM to disk. +3. However, if the disk cannot keep up, RAM fills up, and SABnzbd can only throttle the download speed (which you see in the graph) +4. As soon as the cached data is written to disk, there is RAM available, and SABnzbd can speed up again. +5. ... until RAM gets filled up again due to the slower disk, and the process repeats itself, causing the zigzag pattern. + + +## Solution + +Get a faster disk until you no more get "Download speed limited by Disk speed (...x)" + +And on more difficult setups like Unraid: consult Unraid documentation. \ No newline at end of file diff --git a/wiki/advanced/zigzag-download-speed.md b/wiki/advanced/zigzag-download-speed.md new file mode 100644 index 0000000..7ae31c1 --- /dev/null +++ b/wiki/advanced/zigzag-download-speed.md @@ -0,0 +1,35 @@ +# Zigzag download speed pattern + +## Sympton + +SABnzbd can show a zigzag download pattern like in the screenshot: + +image + +## Cause + +This is caused by a disk that is slower than the Internet newsserver download speed. + +Easy check: after downloading and seeing the pattern, in SABnzbd's upper right corner, click on the wrench symbol ("Status and interface options"), +then click on first tab Status. Check if you see "**Download speed limited by Disk speed** (...x)". If that line is there, it's proof your disk is the bottleneck. + +Then: in the same window, and there click on the Refresh Circled Arrow. After 10 seconds, in the lower part you will see the hardware performance and Internet speed. + +Example of a low spec machine (slow disk for Complete folder, low pystone value): + +image + + +## Explanation: +1. The first downloaded parts are cached into RAM, which is fast. +2. In the background, SABnzbd & OS is writing from RAM to disk. +3. However, if the disk cannot keep up, RAM fills up, and SABnzbd can only throttle the download speed (which you see in the graph) +4. As soon as the cached data is written to disk, there is RAM available, and SABnzbd can speed up again. +5. ... until RAM gets filled up again due to the slower disk, and the process repeats itself, causing the zigzag pattern. + + +## Solution + +Get a faster disk until you no more get "Download speed limited by Disk speed (...x)" + +And on more difficult setups like Unraid: consult Unraid documentation.