Is this the standard now? To get more than 8?
Oh dear, my PC is so obsolete.
Why would anyone need more than 8gb unless in some specific profession? Even 4 is enough.
More than 8Gb is not
necessary to the average pc gamer, but it's more comfortable. I have been hitting memory problems even just by being creative while multitasking. 4Gb leaves you with very little margin though, and some games will not run properly alongside the usual background processes if you only have 4Gb. It's pretty much not enough nowadays.
but...don't know if 16Gb of RAM is using all the ram with my win 7 32bit and gaming...btw you suggest to buy 2xRipjwas-x @8GB each?
First, check if you can install a 64 bit OS, that will allow you to use more than 4Gb. Unless your pc is older than you, you should be able to. Then if you are tight on budget you should weight the price of more RAM against new gpu etc. the stuff you want to do like image and video editing is memory-intensive before anything else though. So if you want to improve that, buying more RAM is the way to go.
One last thing : be extremely wary of mixing different sticks together. Your PC won't kaboom if you do, but you will very probably get horrible performance.
EDIT : actually in the worst case you might get a blue screen if the sticks are completely incompatible.