I am going to buy a LG Television which has a convenient "Time Machine" to do recording.

I should buy an external hard drive to record for instance 10 hours a day.

I prefer a USB key : does anybody have experience how many hours can be recorded on a USB key of 64 Gb (in standard and not High Definition resolution)

I had a 750Gb hdd from true and can record about 226 hours of normal non hd content. So do your math.

A USB key may not be able to Read/Write fast enough for recording and you might experience freezing and long waits when rewinding or fast-forwarding.

I would buy a fast Hard Drive and a Hard Drive enclosure that plugs into your USB port.

A USB key may not be able to Read/Write fast enough for recording and you might experience freezing and long waits when rewinding or fast-forwarding.

I would buy a fast Hard Drive and a Hard Drive enclosure that plugs into your USB port.

This.

My Samsung tests all devices for R/W speed before allowing them to be formatted and recorded to. Most USB sticks failed, Magnetic media always passed.

You'll need a lot more than 64GB too.

A two-hour SD movie is approx 700Mb.

Just out of interest what LG models offer this recording facility?

Most models of "smart" tvs have some sort of recording feature. You cannot use a usb pen drive not fast enough and too small. A 1tb external hard drive is just over 3000 baht.

You'll need a lot more than 64GB too.

Agreed

I have around 1Tb of material waiting to be viewed

It soon builds up