[8.920] effect of IPS on throughput?

Mainboard Jetway NF96FL-525
Processor 1.8 GHz Intel Atom D525 (dual core)
RAM DDR2 800 DIMM 2GB

without IPS

http://www.speedtest.net/result/1881433465.png

with IPS

http://www.speedtest.net/result/1881437557.png

I would expect IPS to slow me down but not by this much - from 100Mbps to <8Mbps