Network transfer speed slow when MinimServer is running

[ElfjeTwaalfje]

I run MinimServer Starter Edition 2.1 on a still going strong DS211 (latest DSM 6.2.4v2). When MS is running I get file transfer speeds of about 25Mb/s (DS to a Windows PC M2 disk ). When I stop MS from the Package Center, the speed is about 70Mb/s. Stop from MinimWatch does not make any difference, still slow.

I checked all there is to be checked as far as the network is concerned before I started shutting down packages.

I am at a loss as how to solve this. Any advise?