Today we where asked to have a view on some servers where the network performance is really poor.
All servers with this issue are placed in branches using 4mbit MPLS connection.
The network perfomance was round about 4 – 8 KB/s.
Supected where 200 – 250 KB/s.
Also the poor perfomance was shown only using TCP/IP.
On UDP/IP the transfer rate was ok.
So we tested every TCP setting you can ever think of:
- TCP Offload,
- Chimeny
- Caching
- Jumbo Frames
- MTU
- and so on
But nothing changed the poor performance.
Since we stumbled over a blog, written on January 2011:
http://exchangemaster.wordpress.com/2011/01/26/windows-7-windows-2008-r2-slow-download
And yes, the servers with the issue are all on Server 2008 R2 Standard Edition (RTM or SP1) and have 48GB of RAM.
—–
It’s not a joke:
We removed 16GB of RAM form a server and the traffic was fast.
We remounted the RAM again, and the network performance was poor again…
—–
After that we decided to ask Microsoft about that “Feature”.
I will post a answer as soon as we have an answer.
Cheers
benedikt
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