size issue

I went out and got a 500 gig hard drive.it is a external. I have a 20 gig C-Drive) and a 40 gig D_Drive) My D-Drive Is starting to crap out I think. Whenever I unrar in D. The computer freezes. but in C-drive everything unrars just fine.
anyways I pluged in my 500 gig and windows says it is 465 gig. a loss of 45gigs due to the conversion factor.
but this did not make any sence because with my 20 gig. I lost 1 gig
and with the 40 gig I lost 1.8 gigs
I just dont see it adding up. I am thinking if I loose 1 gig for every 20 gigs then this new 500 gig should cost 25 gigs not 45 gigs. I am asuming they are made the same. am I out to lunch are is this normal.

Thanks for any responce.
ps my 500 gig is a comstar platinum usb 2.0 hard drive

 

465GB is the correct size for a 500GB drive. With the 20 you don't lose 1, you lose 1.4, and with the 40 you should lose 2.8GB. Bear in mind not all drives are made to be for example 40,000,000,000 bytes, they often go over.

 

also bear in mind that the bigger the harddrive the bigger the default clusters when you format it which also lose you space

 

Thanks guys. 2.8 is right sammorris. I am just bad at math. Do you have any input as in how I should partition this/are if I should. I am thinking 5/100 gigs.
also I had a thought is it possible for me to put any operating system on my external hard drive, and get rid of my C and D- drive.
thinks for any input, as I am pretty new to the big hard drive. This

 

What you could do is put the 500GB inside, partition it off into a 20GB Windows partition (I think 5 is a bit on the small side) and then use your old 20 as an external...

 

ok but the external 500 gig is hooked up by usb.
I meant making 5 partitions of 100 gigs
Thanks for the help.

 

I can think of no reason why you would want to make 5 100GB partitions, rather than just keep one small one for windows and the rest for data. You will see better performance if you just use folders.

 

If using the small partition as the OS partition, I would make it 40GB, if you get into video editing. The temp files can get pretty big, and not all video editing programs flush the temp directory.

 

okay is what I will do. I will make a 50 GB partition for my operating system. And I will have the rest in one big file.
this is the part I do not know. I do not know how to have my operating system start in USB. My 500 GB hard drive is a external USB. my C drive is a 20 GB Western digital that I will be removing. My d drive is a 40 GB Western Digital that I also will be removing because they have slow write speeds. 133 MB/s and my 500 GB is 460mb/s usb2.0

 

I don't have an external, but I am not sure that you will be able to boot from that drive. I know that I would not feel comfortable booting from a USB drive.

 

oh. I did not know I could do that. Thanks is this a fairly easy process. Thanks for The info. it is a great big help. thanks

 

Indeed, and booting from an external hard drive is not easy.
It's a simple procedure to swap the drive out.