First, no storage drive of any kind, HDD or SSD, when formatted and has it's properties displayed in Windows, will show the advertised capacity. It will always be lower due to a difference in the GB units used by Windows and the drive manufactures. Drive manufactures use a decimal GB, or 1,000,000,000 Bytes, and Windows uses the binary GB, whose decimal equivalent is 1,073,741,824 Bytes. This is a recognized but not always understood situation that has existed for years. So there is nothing wrong with your SSD.
My 120GB SSD is shown in Windows as 111.9GB, my 128 GB SSD is ~119GB, 80GB SSD is ~75GB, and my 2.0TB HDD is shown as ~1.8TB in Windows.
I don't understand how this only recently happened, as you said, since it should have been shown in Windows as ~111GB as soon as it was installled. If you click Start, and then Computer, which will show your PCs drives, and if you point and right click on that SSD and select Properties, you'll see both a decimal and binary in decimal form listing of your SSDs capacity.
There is no need to secure erase your SSD, as nothing is wrong with it. It's also a shame, if true, that someone at Intel did not know this and explain it to you, rather than suggest a secure erase, as you said in your post. It is true that a secure erased SSD, which is unformatted and does not have a volume on it, will be displayed in the Intel SSD Toolbox as the advertised size, but Windows won't recognize the drive until it is formatted and has a volume. Once that occurs, you'll be back to 111.8GB, of course.
Yes it is true they told me that. I did not know that was true about the drive not being the size they specified though. Why is that? Marketing trickery? Does it do the same thing In Mac OS? I knew that it would be smaller than advertised sized if changed between bits and bytes but 8 GB? you know apple sells an 8GB Ipod for a quite a bit of money and I feel kinda scammed that I bought a 120 GB hard Drive that I can only use 111 GB of... I don't go to McDonalds and by a cheeseburger and expect to only be able to eat the burger and have to leave the cheese behind... what's the deal with that?
Some people might think of this as marketing trickery, but IMO I don't think so. Just to be clear, the decimal Giga-byte (10 to the 9th power) count of a storage drives capacity is used by all drive manufactures, and always has been as far as I know. There is some logic in the use of the binary Giga-byte count used by Microsoft, since computers work only with binary numbers. The correct prefix for the binary Giga-byte (two to the 30th power) is GiB. Consistency between the two would make this issue disappear, but we know consistency is not always found in our world. Mac has used the decimal GB in their OS's, so you would not see this issue there.
The memory example you mentioned is a good example of this going in the other direction. DRAM memory is spec'd as decimal GB, but actually is GiB.
You're not being scammed on the size of your SSD or HDD, it's just the way Windows reports it. As I said, Windows will show you both counts if you check the Properties for a drive. The decimal count is the exact byte count, and the abbreviated display is in GiB, although they use GB. This is nothing new, but has not been changed by MS.
IMO, if you want to see a real potential scam, check the sizes of various manufactures USB flash drivers in Windows. For example, two 8GB USB drives by different manufactures can have quite a difference in the amount of memory they actually provide, and the price or manufacture guarantees nothing about the size difference.