Upon the advise of the people here, I've recently upgraded my ram to 8GB as I want faster processing when doing photoshop. But even when I close all the images in photoshop but remain just on standby mode (ie with the white dot on). it still consume 2.24G memory. That is astonishing! Although I still can work on it without experiencing any noticeable lack, I wonder why it take up so much memory when I already cleared all images. Only when I quit photoshop and open again, then I get 3.5GB Free as compare to 289 MB Free. Just curious why is it like that.