Question: I've a question which bothers me since quite some time now. I have several environments and servers. All of them are connected to 1 Gbit ethernet swiches (e.g. Cisco 3560).

My understanding is, that a 1 Gbit link should provide 125Mbyte/s - of course this is theory. But at least it should reach ~100Mbyte/s.

The problem here is, that one copy process only reaches ~20Mbyte/s.

I'm aware of these factors but they don't make any difference:

* Source and Destination on the same switch or not
* Copy utility: SCP, Rsync, Windows copy, Windows robocopy
* SMB/CIFS, NFS, iSCSI
* Disk storage: NetApp FAS, locally attached 15k SCSI

With all of these configurations, I never get more than ~25Mbyte/s throughput. The thing is, that if I start multiple parallel copy streams, like 3 times an rsync, i almost reach 90Mbyte/s. I also did some IOMeter tests and found out that the "chunksize" makes a huge difference, but is normally not tunable with the given tools (or is it?).

Jumbo frames are not enabled but I'm unsure if it would make a difference. TOE is enabled on all NICs.

What are the bottlenecks you would think about? Do you have similar experiences? Are these the expected "natural" values?

Thanks in advance

Answer: 
Speed. We load jQuery, jQuery UI from [Google AJAX Libraries API](http://code.google.com/apis/ajaxlibs/), which increases the chance there's a cached version of those libraries in any visitor's cache. And Google's infrastructure / CDN is better optimized for serving these kinds of static files than our own web server.

Other than that, the bandwidth savings are real - those two libraries are quite heavy together.

Con: I don't trust any other host enough to host a library on their site. For any library not listed on Google, we host it ourself.
I think the only real reason is to have always up to date.

I'm against linking libs, scripts, etc because I think my traffic stats are a value to be kept at home.

Moreover it is quite trivial to have the lib hosted and up to date, a cronjob can do the trick easily, efficiently and safely.