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Hard Drive Capacity Confusion, Lucidly Explained
mrklin writes "James Wiebe of wiebetech.com has written a clear example of how hard drive capacity is calculated (PDF file) by hard drive manufacturers (base 10) and OS (base 2). He failed to name how the capacity should be described, though."
With storage prices falling through the floor, does it matter to anyone except whiny nerds whether the byte counts are done in base 10 or base 2?
In the words of William Shatner, "Get a life!"
As far as ordinary users (i.e. anyone who doesn't have to deal with TLBs, memory pages, disk sectors and the like) are concerned, there's really no reason left to use binary units; 2^9 bytes per sector, 8 sectors per filesystem block, etc. are all low-level conveniences that the user shouldn't have to even notice. Though I personally am too used to the binary units to switch easily, the vast majority of users probably wouldn't even notice the difference, aside from their computers finally reporting the right size for their hard disks. Granted, overcoming the huge momentum for binary units will be difficult, but one could always consider it practice for getting the USA to accept metric.
This is not a matter of base-10 vs base-2... a base-10 number is written as "2875" for example. A base-2 number is written as "10100110". A base-16 number is written as "8A3F0"...
This is a matter of UNITS used - like inches vs. feet, or in this case GiB vs GB.
Geez, get the terminiology right...
About two years ago there was a debate about this. Can't remember the details of that debate. Maybe it was when those "mebibytes" were introduced. I still say now what I said then.
I think there should be "short megabytes" and "long megabytes", and the same for gigabytes. Like this:
Then all we need is to get hard drive manufacturers and OS vendors to state whether they are using short or long tons, er, gigabytes.
As to abbreviations, take Donald Knuth's suggestion. Use the capital letter twice to suggest binaryness. 1 MMB = one long megabyte; 1 GGB = one long gigabyte. I like this much better than the now-standardized MiB men-in-black abbreviation for long megabytes (which are still not called long megabytes in the standard, they are called mebibytes, which sounds silly and no one uses it).
Who's with me?
Sunlit World Scheme. Weird and different.
Those are too hard to pronounce. Who not just distinguish them by prefixing the metric ones with the word "metric", as we do with tons and metric tons.
kilobyte = 1024 bytes
metric kilobyte = 1000 bytes
The only relevant issue is the meaning of words like kilobyte, megabyte, and gigabyte. Wiebe describes how you can arrive at two different answers for drive capacity depending on how you define the word "gigabyte," but does so completely uncritically. For example, he describes the drive manufacturer logic and writes that "the drive's claim of 123.5 GB is verified with this simple mathematical formula." But the issue is what the word "gigabyte" means, and the formula presented sheds no light on the word's conventional usage or etymology. I personally was raised to use these terms to correspond the numbers that are powers of two. Wiebe doesn't give me any point of reference to shed light on whether it's reasonable to use the meanings drive manufacturers do. (Of course I already know the answer, but that's beside the point.)
Wiebe uses some other odd logic, exemplified in point 3.7. He writes that the consumer was never cheated, because a drive advertised as having a capacity of 123.5GB had just that in "decimal based" capacity. This is a bizarre way to characterize the complaints. Consumers who believe they were cheated aren't claiming they didn't get 123.5GB for any definition of the word gigabyte. They're claiming they didn't get 123.5GB by the conventional definition of the word as commonly used in connection with computers. In my view, they're right, although I don't personally get too upset about it.
...he ignores the fact that HD manufacturers are happy using bytes which are 8 bits, all the while flaunting the established convention that MB/GB refers to binary megabytes and binary gigabytes. Why don't they specify the size of their HDs in bits?
But personally I strongly reject this "kibibytes" attempt at CS revisionist history. Stick with what CS people have been using as measurements for decades, I say,
Why shouldn't CS people stick to what the rest of the sciences have been using for decades, that "kilo" means 1000? This CS thing of making "kilo" stand for 1024 is an attempt at revisionist history.
There's always another perspective.
Or we could just beat the hard-disk manufacturers with a stick until they understand that most people expect 1 kilobyte to be 1024 bytes :P
You are out of touch. If you conducted a scientific survey of 100 random adults who own PCs and asked them:
"How many bytes are in a kilobyte?" you really think that more than 50 would answer "1024"?
I'd be surprised if more than 10 did, personally.
100% of the non-geek population equates kilo with base 10, not base 2.
This issue reminds me of a practice used in another industry. The auto industry commonly reports horsepower and torque for their cars as measured at the engine's crank/flywheel vs at the wheels. While the measurements themselves are an accurate reflection of an engine's general performance alone you typically do not just buy an engine, you buy a system which is the car. When the engine's performance in measured within the context of the car--meaning at the wheels--then the truth is revealed. That revelation shows, on average, a loss of 10-20% when power is measured at the wheels vs the crank. Which spec do you think a manufacturer is going to release?