How do I determine the optimal maximum simultaneous transfers in Filezilla?

How do I determine the optimal maximum simultaneous transfers in Filezilla?

For this, there is no right or wrong answer.

For me personally, I like setting this to 10.

However, you have to remember that many public/private servers have limits either on the total speed of individual connections, speed per ip address or amount of connection.

If they have total speed, quite frankly setting to 10 will only help in situations where you have many files (as it can save time on the authenticating step.

I just transferred 3235 files from my web server to local - and, whilst every file is very small, and the server has a gigabit link, there is about .5-1 second of authenticating and setting up the connection for each and every file which you just can't help when using FTP. By setting 10 files, I greatly increase the overall time of downloading all the files.

In addition, the reason I like setting this to 10 is because, when you connect to some servers, it is possible (due to many factors) to start a transfer at a very low speed (e.g. the server may be under load), and the more connections you have open, the higher the chance of utilising higher speeds, due to the fact that they may be equally sharing the speed between connections (which is quite common).

With the exception of a couple of sites that do have transfer limits, I personally set this to 10 on my machine and have for many years. I recommend you do the same - and check the rules of the server you are connecting to as they may have rules. (or no rules, but, just limit you anyway!).

Note that if you are only transferring a few (smallish) files, this really will not make much of a difference at all.

As for I/O, again, this is a hint to try and get a bit more out of the target server. It is highly possible to get the same speed from a single connection as with 10. Windows has a great read/write cache ability and I highly doubt that this will be a bottleneck. If you do want to test, you can always fire up Process Explorer and look at the I/O graph to see if it is anywhere near max.

I add my voice to William Hilsum in saying that there is no right or wrong answer here, since it all depends on the speed of the source(s).

Basically, if your connection to any one source is as fast as your bandwidth allows, then there is no reason to have more than one transfer at a time. Having more than one transfer will then only place unneeded burden upon your network card and actually slow-down the total transfer bandwidth.

Having 10 simultaneous transfers only makes sense if each of the servers can only manage one-tenth of the bandwidth, so that together you make a full use of your entire bandwidth.

I wouldn't worry too much about disk usage, as the local disk is probably faster than the network and can keep up with it no matter the demand.

In conclusion, the maximum number : 10, only makes sense when dealing with slow sources. A lower value might actually get you some small improvement, but which will probably be hardly measurable at all. So leaving this value as 10 is practically good enough.