I will start video editing with kdenlive soon. I have a few questions regarding the hardware necessary for avchd editing:

(1) which graphic card is necessary to edit avchd videos
(2) how can I use vdpau in kdenlive (nvidia)
(3) is there a distribution specially suitable for video editing (currently I am using MINT)

Thanks for your help,
Alex

You could consider editing with proxys - smaller re-encoded files, that get replaced with original files when you render the final clip. That way, you don't need blazing fast hardware, even though it would come in handy when rendering.

Thanks, but using vdpau should also help to increase the speed of kdenlive. But how can I use kdenlive with vdpau?

If the version of ffmpeg / libav on your system is built with vdpau support, then kdenlive will automatically use it.

You must have a fairly recent Nvidia GPU in order to utilize VDPAU.

And how can I check if ffmpeg / libav is built with vdpau support?

MLT and thereby Kdenlive no longer automatically uses VDPAU. It will only if the builder uses MLT configure --avformat-vdpau. It is no longer enabled by default because it introduced too many compatibility issues and instability with parallel processing.
Basically, the answer at the moment is the graphic card will not make much difference.

Ok thanks. We are now using a NVIDIA GTX 570 and we hope to use the full graphic power in the future :-)
Currently we are running KDENLIVE with proxys.

>I am new to this. May I know where can I get proxys?

chloe23, proxies are a built-in feature of kdenlive. Enable them in the menu "Project / Project Settings / [X] Proxy clips".

@OpenThinking, chloe23's hyperlink to commercial software should alert us that this is spam and has nothing to do with kdenlive or open source community.