Be Smart enough to Recognize TB vs Tb GB vs Gb MB vs Mb KB vs Kb

We often see the texts TB, Tb, GB, Gb, MB, Mb, KB, Kb from common electronic products’ feature description. For example, when we buy an External Hard Drive, we see its size like xxx MB or xxx GB; or when we buy a SSD drive or a Macro SD card, we see their speed like xxx Gb/s or xxx Mb/s.

What Mistakes do People Often Make ?

Consumers might not realize that they are easily silly to ignore some important technical description from the items package or related web page. Those technical descriptions actually expose important information to us. For example, the technical data units. But do you really understand them?

TB is NOT Tb, GB is NOT Gb, MB is NOT Mb, KB is not Kb

What the common mistake which we make is that we do not realize the different between GB and Gb, MB and Mb, KB and Kb etc.

Now please remember: GB is not Gb, MB is not Mb, KB is not Kb

What the Correct Numbers about Storage Size or Speed Measure Units Are?

First, we start from basic concepts:

1 Byte = 8 Bits

B is the symbol of Byte

b is the symbol of Bit

Now we have other concepts which are defined by some international group such as ICE:

1 KB = 1 Kilobyte =  210 = 1024 bytes

1 Kb = 1 Kbit = 1000 bits

1 MB = 1 Megabyte = 220 = 1048576 bytes

1 Mb = 1Mbit = 1 000 000 bits

1 GB = 1 Gigabyte = 230 = 1073741824 bytes

1 Gb = 1 Gbit = 1 000 000 000 bits

1 TB = 1 Terabyte = 240 = 1099511627776 bytes

1 Tb = 1 Tbit = 1 000 000 000 000 bits

You can find more units from the post which we posted previously.

So now we should know if you see 100 Gb on some products, it does not mean the number is 100 Gigabyte, it is 100 Gigabit.

Here we have an example:

When you buy a SSD from Amazon:


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We can see it is a 250 GB SSD which means its storage size is 250 Gigabyte. We also see another information which is about SATA 6 Gb/s, which means the SSD can connect to SATA III interface to transfer data at the speed of 6 Gigabit every second.

However we should know 6 Gigabit is NOT 6 Gigabyte.

If you want to convert the 6 Gb/s to bytes, you should use the number to be divided by 8

6 Gb/s = 6/8 GB/s = 0.75 GB/s = 750 MB /s

Which is a fast data transfer since it uses SATA III.