high memory latency, slow loadings

hi,

first i will start with my spec

P4 3.00GHz HT
ECS PF4 Extreme Mobo
1GB Memory (512mb x 2)
ATI X550 Series 256mb PCI-E
160GB WD Sata HD

using eventest, Memory reading is around 2000MB/s, Writing speed is normal and Latency is 250ns.

i checked my memory with other pc, its working fine. as well as cpu, working fine. so what is causing so high latency and reading speed? my motherboard?

thanks in advanced.