If I have several to take down, I sort them into like kinds first. The standard Gateway, Compaq, HP, etc that have all Phillips screws, I can average 3 minutes. Dell clamshells like Optiplex have mostly slide locks or levers and if I am on my game I can get those in 2 1/2 minutes. The ones that have #15 Torx take me 4 minutes because I don't have a bit and have to go manual. The old ones like 486 IBM machines take a little longer because I have to check each time to see what tools I need and how everything comes apart. Same thing for smaller Emachines. Older Apple....GRRRRR. Some are a beast and take forever, over ten minutes, but they do reward me with a nice ceramic Motorola chip. Those iMac all in ones and IBM dumb terminals almost 30 minutes. I'd say if I were going to sort them and do the easy ones first, I could get close to 20 per hour for a little while. No way I could hold that pace for long though and you won't get all easy ones. Actual numbers, the most I've done in one streak is 33 and it took just over two hours.