Hi, i’m looking into buying a Pikvm and I’m a bit confused about this
Isn’t a pikvm just basically pretending to be a monitor. Why is this not an issue when using a monitor with those systems?
or is this not a problem with v4? (if so, maybe add that to that stickied post so it’s clear, because to me it’s not clear if it’s limited to v3)
It is often less of a problem with the v4 Plus, but dumb/out of spec signals can still trip it up.
The biggest issue is physics, the v3 HAT and the v2 DIY only have 2 CSI lanes from the Pi4 to transfer the signal through, this limits the resolution to 1920x1080 @ 50Hz (or less). The v4 devices use a custom carrier board and a CM4 module to bump this to 1920x1200 @ 60Hz.
The reason this matters is the engineers in Silicon Valley and Hong Kong/Taipei/Shenzhen all assume 60Hz is a reasonable default refresh rate, to the point where many devices can NOT actually negotiate at 50Hz or 30Hz, or at a resolution not 1080p, which means they are basically instantly incompatible with everything but the v4. The trouble is this is only an “issue” at the most critical of times, like when there isn’t an operating system that can be more flexible, so in the BIOS and firmware update screens that you REALLY want to know is done so you don’t brick something by unplugging power, you just get a black screen instead.
A common workaround is using an HDMI splitter to go to a real monitor and the PiKVM, but that isn’t always feasible or practical.