With help of perfmon you can check following memory related counters:
SQLServer:Memory Manager\Memory Grants Pending
SQLServer:Memory Manager\Total Server Memory (KB)
Memory\Pages/sec
Also you can add few more counters and check memory as well as any other hardware bottlenack if any.
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"Thare are only 10 types of people in the world:
Those who understand binary, and those who don't."