I've seen it take up to 8 months for them to fully decend in a large breed (pup from my last litter) but you could feel that they were both present and accounted for by 8 weeks old. If you can not feel them then the chances that they will decend are slim.
I prefur to have my Bordeaux with fur instead of a cork and bottle ;)
I have personally have had pups here and there with one decended at 8 weeks and by 4-6 months it was down. I completely agree with Red that it can take up to 8 months. My vet has also told me 8 months.
I have heard it can take between 6-8 months. They can also go down and one or both can go back up again. It can be frustrating when someone is looking for a show/breeding prospect, because I wouldn't feel comfortable selling it as such until both were down and likely to stay down.
Other breeders that I know, sell them as pet only if they are not both down by 8-10 weeks. Even though, they may have eventually both descended.
When I purchased Tally Ho as a show/breeding prospect, he only had one down. I use to say he was my little squirrel because he liked to hide his nuts. One was in the shaft, so daily I moved it down to the sac. It eventually stayed. I recently sold one of his pups that is having the same issue. It is there, but the people who took him as a pet are not really interested in pushing it down where it belongs daily. So I guess they will just have to deal with the issue in a couple of months when he goes into be neutered. If for some reason the teste is up when the bands close, there is no getting it down. So if you can feel it, keep trying to work it down. I have had dogs with both down and then have a judge check them with aggressive or cold hands, the they suck that baby right back up again. So you must use care when handling your young males.
He's your friend,your partner,your defender your dog.You are his life,his love,his leader. He will be yours faithful and true to the last beat of his heart.You owe it to him to worthy of such devotion