From 2be74ef3308fb51e0f300be9dd758a38698efb0a Mon Sep 17 00:00:00 2001 From: Maxim Devaev Date: Sun, 5 Apr 2026 01:46:27 +0300 Subject: [PATCH] update --- README.md | 2 +- docs/faq.md | 18 ++++++++++-------- docs/video.md | 2 +- mkdocs.yml | 1 + 4 files changed, 13 insertions(+), 10 deletions(-) diff --git a/README.md b/README.md index 8647af6a..e4ab3f53 100644 --- a/README.md +++ b/README.md @@ -14,7 +14,7 @@ The website: [pikvm.org](https://pikvm.org). Also check out [the documentation]( * Can be made based on **Raspberry Pi 2**, **3**, **4** and **Zero2W**; * *Raspberry Pi 5 is not supported right now. It doesn't have GPU video encoders, therefore, there is no point in using it for PiKVM, it will not give any performance boost for this case. The Pi 5 is a great device, just not suitable for PiKVM.* * **FullHD video** using advanced **HDMI-to-CSI bridge** or **USB dongle**; -* Extra low **35-50ms H.264 latency**; +* [Proven](https://docs.pikvm.org/latency) lowest **35-50ms H.264 latency** among all KVMs on the market; * WebRTC, H.264-over-HTTP and MJPEG video; * Bootable **Virtual CD/DVD** and **Flash Drive**, ability to store images on **NFS**; * USB **Keyboard** and **mouse** (with leds and the wheel), Bluetooth HID, Mouse jiggler, full support of PS/2; diff --git a/docs/faq.md b/docs/faq.md index 8debbeb3..940022b7 100644 --- a/docs/faq.md +++ b/docs/faq.md @@ -74,22 +74,24 @@ If you run into any issues you can check this page which will list common errors * General hardware video capture differs from software streaming and introduces additional latency. +??? question "Where does the cursor/video latency come from?" + [See here](latency.md). + + ??? question "Can PiKVM do 4K video?" * For HDMI-CSI bridge, no. There is not enough bandwidth in the CSI bus for that much data. 1080p50 will max out the bandwidth. * For the USB capture devices: technically yes, they will down sample to something smaller to meet the USB 2.0 bandwidth limitations, so the source may be 4k, but the stream will not. * The 4K real-time video will not fit through the network anyway. -??? question "Where does the cursor/video latency come from?" - Here is the chain of transferring an image to your browser or VNC client. - - `Capture device -> Compression -> Network -> Decompression -> Rendering` - - 100-200ms is very, very fast for this. But we are working to speed things up even more. - ??? question "I am expecting to see 60fps and I am not, why?" - PiKVM receives the entire signal, but then the encoding is the bottleneck. For 1080p, this is no more than 30 fps. V4 throws out every second frame of 60 hz/fps, and 30 fps is encoded. V3 and DIY can't process 60 hz and is only able to capture 50 hz, and in the same way they take every second frame, all you get out is 25 fps. The reason why V3 and DIY does not encode 30 out of 50 is that the picture will be jerky, but smooth at 25. + PiKVM receives the entire signal, but then the encoding is the bottleneck depends of the device model. + + [PiKVM V4](v4.md) is able to encode full 60fps with [enabled H.264 boost](video.md#boost-pikvm-v4-to-60fps-h264). + + [PiKVM V3](v3.md) and DIY can't process 60Hz and is only able to capture 50Hz, and they take every second frame to encode, so you get only 25fps. The reason why V3 and DIY does not encode 30 out of 50 is that the picture will be jerky, but smooth at 25. + ??? question "Does PiKVM support sound?" Yes but the only officially supported version is the PiKVM V3+ devices, V2 we will attempt best effort but ultimately we do not support CSI modules or USB. diff --git a/docs/video.md b/docs/video.md index b6611274..2a884648 100644 --- a/docs/video.md +++ b/docs/video.md @@ -43,7 +43,7 @@ video. ## Boost PiKVM V4 to 60fps H.264 By default, the performance of PiKVM in 1080p mode is limited to 30fps, but this limitation can be lifted. -The result will be a slightly lower video latency and a full 60fps stream +The result will be a slightly lower video [latency](latency.md) and a full 60fps stream with a slight increase in processor temperature (it's not critical for both [V4 Plus and Mini](v4.md), as they have a very good cooling system). It will also double the consumption of network traffic. diff --git a/mkdocs.yml b/mkdocs.yml index 7d373355..da9dec1d 100644 --- a/mkdocs.yml +++ b/mkdocs.yml @@ -133,6 +133,7 @@ nav: - "WebRTC configuration": webrtc_config.md - "Tuning HDMI EDID": edid.md - "HDMI passthrough": pass.md + - "Latency": latency.md - "Peripheral devices": - "ATX board": atx_board.md - "USB configuration": usb.md