Reputation: 4885

Are "65k" and "65KB" the same?

Upvotes: 5

Answers (15)

Arnkrishn

Reputation: 30434

In terms of data transfer rates - 65k implies 65 kilobits and 65KB implies 65 KiloBytes

Check this http://en.wikipedia.org/wiki/Data_rate_units

cheers

Upvotes: 4

Krisztián Balla

Reputation: 20361

There you go:

kB = kiloByte
KB = KelvinByte
kb = kilobit
Kb = Kelvinbit

Use the bold ones! But be aware that some people use 1024 instead of 1000 for k (kilo).

My opinion on this: kilo = 1000. So the first one who decided to use 1024 made the mistake. If I am not mistaken 1024 was used first by IT engineers. Later they found out (probably some marketing genius) that they can label things using 1000 as kilo and make things look bigger than they actualy are. Since then, you can't be sure which value is used for kilo.

Upvotes: 1

Dave Dopson

Reputation: 42704

"Officially", 65k is 65,000; however people say 65k all the time, even if the real number is something like 65,123.

Typically 65k means anywhere from 64.00001 to 65.99999998 KiB or sometimes anywhere between 63500 and 64999 bytes ... ie, we aren't all the precise most of the time with sizes of things. When someone cares to be precise, they will be explicit, or the meaning will be clear from context.

65 KiB means 65 * 1024 bytes. .... unless the person was rounding. Never trust a number unless you measure it yourself! ... :)

Hope that helps,

--- Dave

Upvotes: 0

Christian

Reputation: 26387

From xkcd:

I would take 'kibibyte' more seriously if it didn't sound so much like 'Kibbles N Bits'.

Upvotes: 54

darron

Reputation: 4394

Like most have said, 65KB is 66560, 65k is 65000. 65KB means 66560 BYTES, and 65k is ambiguous. So they're not the same.

Additionally, since there are a few people equating "8 bits = 1 byte", I thought I'd add a little bit about that.

Transmission rates are usually in bits per second, because the grouping into bytes might not be directly related to the actual transmission clock rate.

Take for instance 9600 baud with RS232 serial ports. There are always exactly 9600 bits going out per second (+/- maybe a 5% clock tolerance). However, if those bits are grouped as N-8-1, meaning "no parity, 8 bits, 1 stop bit", then there are 10 bits per byte and so the byte rate is 960 bytes/second maximum. However, if you have something odd like E-8-2, or "even parity, 8 bits, 2 stop bits" then it's 12 bits per byte, or 800 bytes/second. The actual bits are going out at exactly the same rate, so it only makes sense to talk about the bits/second rate.

So 1 byte might be 8 bits, 9 bits (ie parity), 10 bits (ie N81,E71,N72), 11 bits(ie E81), 12 bits (ie E82), or whatever. There are lots of combinations of ways with just RS232-style transmission to get very odd byte rates. If you throw in RS or ECC correction, you could have even more bits per byte. Then there's 8b/10b, 6b/8b, hamming codes, etc...

Upvotes: 4

Brian

Reputation: 25834

65KB normally means 66560 bytes. 65k means 65000, and says nothing about what it is 65000 of. If someone says 65k bytes, they might means 65KB...but they're mispeaking if so. Some people argue for the use of KiB to mean 66560 bytes, since k means 1000 in the metric system. Everyone ignores them, though.

Note: a lowercase b would mean bit, rather than bytes. 8Kb = 1KB. When talking about transmission rates, bits are usually used.

Edit: As Joel mentions, hard drive manufacturers often treat the K as meaning 1000. So hard disk space of 65KB would often mean 65000. Thumb drives and the like tend to use K as meaning 1024, though.

Upvotes: 35

Petruza

Reputation: 12276

As many said, K is tecnically Kilo, meaning Thousand (of anything) and comes from greek. But you can assume different units depending on the context. As data transfer rates are most often measured in bits, K in this context could be assumed to be Kilo Bits. When talking about data storage, a file's size, etc. K can be assumed to be Kilo Bytes.

Upvotes: -1

David Webb

Reputation: 193716

65kB can be interpreted to mean either 65 * 1000 = 65,000 bytes or 60 * 2^10 = 66,560 bytes.

You can read about all this and kibibytes at Wikipedia.

Upvotes: 6

Dan Diplo

Reputation: 25339

Strictly speaking, the former is not specifying the unit: 65,000 What? So, the two can't really be compared.

However, in general speech then most people mean 65K (note it's normally uppercase) to mean 65 KiloBytes (or 65 * 1024 Bytes).

Note 65Kb usually denotes KiloBits.

Upvotes: 0

jjnguy

Reputation: 138884

From Wikipedia for Kilobyte:

It is abbreviated in a number of ways: KB, kB, K and Kbyte.

In other words, they could both be abbreviations for Kilobyte. However, using only a lowercase 'k' is not a standard abbreviation, but most people will know what you mean.

Upvotes: 2