When I used USB keyboards with my tablets in host mode, there was a lag when typing, and I just noticed someone else reporting this in a thread about bluetooth keyboard lag.

Has anyone else seen lag when typing on a tablet with a USB keyboard?

If this is a common problem, it could be that the text input system itself is unable to cope with very fast typing speeds. (And that would make sense as it was originally designed just for the on-screen keyboard where typing speeds are slower.)

It would also explain the Bluetooth keyboard lag which many have reported.

If this is a widely-observed problem, I'll try to add this to bugzilla. I know USB keyboards aren't officially supported, but BT keyboards are, and the cause of both lags may be the same.

yeah, i have a usb keyboard and have the same lag effect, is really obvious when typing quickly.

I think I'm the one from the other thread who mentioned lag on USB keyboards. It would definitely be great to add this to bugzilla, as I would love to have this issue fixed. It is currently my main gripe, now that my other main gripe is figured out. I just had another idea that could give us some insight. This post describes hildon-input-method, which eats a lot of CPU when typing, and it mentions how this could probably be gotten rid of if you were using another WM. Does anyone use KDE on their n810? Have you tried using the USB keyboard through KDE? I haven't gotten advanced enough to install something like KDE, but that might give us a hint.

I sometimes get lag on BOTH internal and external keyboards on the n810. Both USB and Bluetooth. So its keyboards in general (in my case)

It's not often I have to type fast on the N800 but like the others, I have observed that there is some latency when I'm typing fast, too.