Have you research such a problem?..
When NT performs intensive write operations, it's console becomes very slow. It is not possible to connect to any running application. We have written simple program that writes several thousand blocks of 30 - 60Kb on disk. When it executes, NT console stops responding. Microsoft sais that if we see 100% disk utilization, it tells aboult disk bottleneck. We have seen this issue on various hardware platforms: desktop PC with EIDE controller, Compaq Proliant server with Smart-2/P Array an others. When similar program runs in OS/2, this OS behaves better: OS/2 itself and its tasks responce more quickly.
Could you give me a hint, what is the main cause of such NT behavior and are there any settings improving that NT responce?