So, I picked up a 320GB PS3 yesterday, and I am always aware that the system actually calculates a GB differently then what we assume. Like it isn't 1000MB = 1GB. Accounting for this I assumed that I should have around 300GB's of space on my new system. When it started I had 298GB's of theoretical space, however, without anything installed yet, I had only 260GB's left. Does the OS need around 40GBs? So, in reality I only have a 260GB console. That's like 60GB's worth of lies.

That's very strange. I know that 250GB 360's actually come to around 238, but you're being ripped off 60 gigs which is very weird. Where did you get the PS3 from? Is it brand new?

Yeah, that is weird. 
 
I have an 80 gig PS3 and by your calculations I'd only have 20gigs of free space. 
 
I think I started with 74gigs of free space or something when I first got it.

Anything come preinstalled? Demos perhaps. 
 
Worse comes to worse, pull the drive out and check for its size on the label.

I have an old 40 GB PS3 and while the OS isn't up to date, it still leaves me with aroun 37 GBs. So either something is wrong with the hard drive, or the wrong hard drive came with it.

It's brand new. My previous 60 GB, only had 55GB accessible, which is understandable.

The system reserves a certain amount for caching. The interesting thing to note is that it doesn't use a set amount of space, it uses a percentage. The bigger the hard drive, the bigger the cache. In the newer systems they did leave some overhead for the OS as well.

Do a format in the off chance stuff is installed and you just don't know about it, but if it's still missing I would call up Sony and see if it's under warranty. The PS3 hard drive is just a standard laptop hard drive, so if you really wanted to you could just buy one of those dirt cheap 1-2TB ones and replace it if sony says they won't do anything for you.
 
I won't go into the technical mumbojumbo, but it's a problem with all hard drives. The stuff that determines how much space is on a hard drive is never 100% what's on the box and will always be a few GB off the mark. Some times it's something small, but other times you get a bad drive like yours and it's just missing more then what's considered acceptable looses.
 
At least that's my understanding of it all.

why do you even need that many gigs

I have the same model and I had 290.

i put a 320 in my 60 myself and have 294

" why do you even need that many gigs "

" @FancySoapsMan said:

" why do you even need that many gigs "

never have to think about it again.  and it's not that expensive. "

I put a 320 gig in my PS3. Best thing I ever did.

Did it come with stuff pre-installed? Like Home? 
Seems off that that much was taken up.

That shouldn't happen, I got the 80gig PS3 and only had to give up like 5 or 6 gigs for the os.  

Why is it not standard? Because my 80GB PS3 brand new, had 68/72Gb of free space, with nothing pre-installed; I am not calling people liars, but why do some people only say 5 or 6 GB missing, while others like myself had 8 or more? Does it vary from individual system to system?

it's the OS but i do think that is a lot for nothing. i think you can delete and reinstall and see if that works.

" Yeah, that is weird.  I have an 80 gig PS3 and by your calculations I'd only have 20gigs of free space.  I think I started with 74gigs of free space or something when I first got it. "

" @LiquidPrince: Getting less disk space than is advertised is normal, believe it or not. You haven't been ripped off, that's just how it works.  320GB is the unformatted capacity. When a disk is formatted, partitioned, and a file system put into place, space is taken up. That space you're missing is still there, it's just being used for other things like directories, journaling (to prevent data loss and verify integrity), metadata, volume encryption data, etc. "