On a hard disk 72 Gigabytes is 72,000,000,000 bytes. In main memory, it's 72*1024*1024*1024 = 77309411328 bytes. If you have a hard disk that advertises a size of 72 Gigabyes, and you format it as, for example, an NTFS file system under Windows, you'll end up with about 65 Gigabytes of free space for files, due partly to the difference in measuring a gigabyte as either 1000^3 or 1024^3 bytes, and the space used by NTFS for directories and allocation maps within the file system.
It's pretty large. Most computers only come with 40-80GB of HD space standard and you have to pay for the upgraded. 72GB will take you a while to fill up.
A board with DDR3 is a waste of money at the moment. Motherboard/CPU combos can not even utilize it at the moment. I have seen mixed reviews on that Asus board. It is kind of tight for expansion. As much as I like Asus boards - the nod goes to Gigabyte in these two comparisons.
Fairly big, usually a 100GB memory is pretty big, but if you're using a laptop, I don't think you'll be filling half of that anytime soon.
Bigger than 71GB and smaller than 73GB.
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