increasing the write block size for high latency

[L. A. Walsh]

Dan Stromberg wrote:
> On Tue, Jul 8, 2014 at 8:07 AM, Adam Edgar <aedgar at research.att.com> wrote:
>   
>> It seems the issue is indeed in the ssh layer. scp has the same issue and some work has been done in “fixing” that:
>>     
----
That's a separate issue.

rsync's performance WITHOUT ssh -- running locally is 100 times slower 
than a
large buffer program.

Even over ssh, one can get over 100MB/s with the stock source.

Locally, it's read/writes to files and pipes that are the problem.