Stating cache size (which prefix is used)

[Nestea_Zen]

When saying 512 KB L2 cache, what is meant?
524,288 kibi? But just abbreviated to 512 for convenience or are it really
512 000 bytes?


thanks for reading.

[Hagar]

Memory chips are always counted in binary, this is hardware related (address lines).
Harddisks has no such direct relation to hardware, and may just as well count in decimal.

[Nestea_Zen]

so what about those address lines.
Why is the 512 KiB L2 cache memory multiplied by 1024 when referring to those?

If I do not missunderstand your post...

[Hagar]

If we imagine there are no address lines, there can be just one memory location, right?
With one address line, which is either low or high, we can select 2 locations.
Two address lines makes 4 locations, three lines makes 8 locations, and so on. It is all about binary arithmetic.
A memory chip has no 'empty' locations, so the only way to count is binary.

A HDD on the other hand, has no address lines. It is just an area that is divided into an arbitrary number of locations.

[Nestea_Zen]

I suppose you mean
four lines have 8 locations, or...

so how do i calculate this.
because if N*2, so how is this calculated:
link
512/32=16 is AFAI understand.

[Hagar]

No, 3 lines. 2 to the power of 3 is 8.
Your link is about word length, that is not the same as addressing. It just means that one location contains more than one byte.

Binary:
http://www2.cs.uregina.ca/~rbm/cs100...ry/binary.html
http://en.wikipedia.org/wiki/Binary_numeral_system

[Nestea_Zen]

hmm know I know.
because there are 4 cols, 2 rows or 4rows, 2 cols.

power of two
well I know that one. but you wrote
> If we imagine there are no address lines, there can be just one memory location, right?
> With one address line, which is either low or high, we can select 2 locations.

so it was a little bit confusing, the moment I read it.

Your link is about word length, that is not the same as addressing. It just means that one location contains more than one byte.

so how is this calculated.

I found that:
cs.ucla.edu
still, somehow this does not fit in my brain, for the moment ^_^;.


thank you for now