Well performance is one concern but i again say i want to utilize maximum memory on windows box as there is 4 GB ram and most of it is free.Right now OS utilizing some memory and oracle utilizing only 1 GB of ram, 2-2.5GB is free most of the time. So i decided to utilize the free memory. This is the reason behind all this. I know how to enable VLM. As my favourite OS is Linux, I have configured 12GB instance on 32 bit machine with 16GB RAM. I successfully hit more than 1000 active users on that server and it didn't gave any error. So here my goal is to create 1.7GB oracle instance on 32 bit windows plateform which will work efficiently. Please suggest me how i will size my sga with in 1.7GB Limit and also how much memory i will give to PGA. Remember I need efficient, effective, optimized settings with 1.7GB restriction.