Upgraded to 8GB of Memory, lost 4GB of Storage Space

[Trauma1]

I upgraded the memory in my 13" MacBook Pro (Mid-2010) from 4GB to 8GB using the Kingston chip from buy.com:
http://www.buy.com/prod/kingston-ap...z-sodimm-c7-imac-and/q/loc/101/220206967.html

I powered back on, it shows 8GB under Memory in the About This Mac settings. Everything seems to be working fine, but I just noticed my Finder shows 1.7GB of storage available. Before I had around 5.8GB free. I've restarted the computer, and the trash can is empty. What happened to the 4.0GB? At the risk of sounding like an idiot, did the 4GB upgrade in memory come from a 4GB sacrifice in storage? I read the instructions on memory upgrade from Apple's support page, but there was no mention of anything other than unscrewing the back, replacing the chips, then screwing it back on.

 

[simsaladimbamba]

Take a look at DiskInventory X, OmniDiskSweeper, JDisk Report or GrandPerspective to see where your HDD space went to.

It will probably be the "sleepimage" inside private/vm, which can be safely deleted.
Also know, that having less than 10 to 20 % of the HDD's capacity free is not recommended.

 

[mulo]

yes, the system keeps a backup file of your RAM, so if you had 4GB RAM and went to 8GB RAM its going to require an additional 4GB to hold the backup file.

this file is there in the case that your MBP should run out of power while sleeping.

 

[Trauma1]

Take a look at DiskInventory X, OmniDiskSweeper, JDisk Report or GrandPerspective to see where your HDD space went to.

It will probably be the "sleepimage" inside private/vm, which can be safely deleted.
Also know, that having less than 10 to 20 % of the HDD's capacity free is not recommended.

Yep, it was the sleepimage. That's a very informative link.

Thanks, and thanks for the heads up about the disk utilities.