we all know that RAM is measured in 2^10 units, 1.e. 1 kilo = 2^10=1024, etc, which least to a difference of 7.3% when we come to GBytes (2^30 = 1,073,741,824). So a 1 TB which is in fact 1000 "GB" HD only holds about 930 GB of real data. In fact even this is confusing, OS X 10.4 and lower reported old style GB, and sometimes around 10.5/10.6 (I don't remember exactly) Apple started to use the HD-makers definition of "GB" so now OS X will report not 930 GB but ~999 "GB"

Now how about SSDs. When you buy a 250 GB SSD, what exactly do you get, how is the GB defined? Do you get GB (2^30) or "GB" (10^9)

and furthermore, assuming 256 GB SSD means 2^30 *256 if you hook this up to a 10.6/10.7 Mac, what does the OS report? does it report like RAM (i.e. 256 GB) or like new style "GB" (256*1.073=274.6 "GB"

Hope the question is not too confusing

Me haid is hurting - just buy a drive and be done with it...

but that wouldn't be fun. Plus it's a 7% difference, if everything I bought came in 7% bigger size that would be awesome

OS reads SSD just like a HD.

Some SSDs have lower net capacity due to garbage collection.

Quote
sekker
OS reads SSD just like a HD.

Some SSDs have lower net capacity due to garbage collection.

Some SSDs have garbage collection without loss of capacity?

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MR/F Guestmap: [www.mapservices.org]

Black, could you please indicate which SSD you bought (120 GB, 128 GB) and what does Finder say regarding Capacity? A screen shot would be nice. Many Thanks!

Sure, will do in a minute or three.

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MR/F Guestmap: [www.mapservices.org]

It's a Sandisk Extreme 120, labeled "120.03 GB PI=263" by Disk Utility.



Mount Point : / Capacity : 119.69 GB (119,690,149,888 Bytes)
Format : Mac OS Extended (Journaled) Available : 48.62 GB (48,618,799,104 Bytes)
Owners Enabled : Yes Used : 71.07 GB (71,071,350,784 Bytes)
Number of Folders : 210,127 Number of Files : 726,281


===So about 600 MB missing from formatted capacity?

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MR/F Guestmap: [www.mapservices.org]

thanks!

Exact same info for my mini's SSD (not surprisingly.)

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MR/F Guestmap: [www.mapservices.org]

An SSD GB is like a HD GB... except faster.

Quote
Jem
An SSD GB is like a HD GB... except faster.

LOL!

OK, I was asking because I saw some 128, 256 and 512 GB SSD and I thought maybe they measure it like RAM (2^30) rather than 10^9

i think the bits on an SSD are square, and the bits on a platter drive are round.

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[www.giyf.com]

Some SSDs have lower net capacity due to garbage collection.

That's what happens when you don't empty the bit bucket.

SSD GBs are definitely faster.

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Quote
mattkime
SSD GBs are definitely faster.

SSD GBs get cheaper while you're dragging your feet on installing them.

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MR/F Guestmap: [www.mapservices.org]