Here we go..
A bit is the smallest unit of data in a computer; has a single binary value of either 0 or 1 A byte is a unit of information that is eight bits long. (half a byte, or 4 bits is called a nibble)
Computer storage is measured in byte multiples; which are based on powers of 2. Because humans deal mainly with the decimal system, the resulting number is usually 'rounded off' for humans to better comprehend.
1 Kbyte = 1024 bytes = 2^10 bytes = 1,024 bytes 1 Megabyte = 1024 Kbytes = 2^20 bytes = 1,048,576 bytes 1 Gigabyte = 1024 Mbytes = 2^30 bytes = 1,073,741,824 bytes 1 Terabyte = 1024 Gbytes = 2^40 bytes = 1,099,511,627,776 bytes 1 Petabyte = 1024 Tbytes = 2^50 bytes = 1,125,899,906,842,624 bytes 1 Exabyte = 1024 Pbytes = 2^60 bytes = 1,152,921,504,606,846,976 bytes = approx. 1 billion GB
-----Original Message----- From: Jay Orr [SMTP:orrjl@stl.nexen.com] Sent: Thursday, March 30, 2000 10:52 AM To: Karl Swartz Cc: toasters@mathworks.com Subject: Re: benchmark
Humm... Fun.. Do you know off hand how Solaris and netapp defines a MB or GB? In moving around files I started thinking about this, since depending on what tool you use you get file sizes in "bytes" "kbytes" "MB" or "GB" (a la gnu df, solaris df, etc...)
On Wed, 29 Mar 2000, Karl Swartz wrote:
Uh, if I can ask a simple (stupid?) question - I was looking at the
source
code for postmark and noticed this :
#define KILOBYTE 1024 #define MEGABYTE (1000*KILOBYTE)
Isn't a megabite 1024*1024?
It depends on who you ask. Long ago, disk vendors decided that they could make their disks look bigger if they defined MB to be 2000 sectors (assuming 512 byte sectors, or 8000 sectors for 128 byte sectors), and GB became 1000 MB. Of course they also talked about unformatted capacity to further inflate the size over reality.
In a similar vein, telco people talk about 1K = 1000. The 64K B- channel in an ISDN line is 64000 bits per second, not 65536.
I'm not sure about networking, but I think FDDI and 100base-T both have a data rate of 100 * 10^6 bits/second, not 100 * 2^20. (Not to be confused with the signalling rate, which as I recall is 125 * 10^6 for FDDI with some flavor of 4/5 encoding, and possibly something similar for 100base-T.)
What's right for Postmark? Good question. It looks like Jeff picked the standard for disk sizes, but it's not clear that's the standard most applicable to this case. Aren't standards wonderful? :-)
-- Karl Swartz Network Appliance Engineering Work: kls@netapp.com http://www.netapp.com/ Home: kls@chicago.com http://www.chicago.com/~kls/
Jay Orr Systems Administrator Fujitsu Nexion Inc. St. Louis, MO
Yes, we all know the theory, but I'm talking real world. As the thread reads, some vendors use 1000 KB = 1MB, while some don't. I am asking what is implemented. Do the majority of the unix vendors adhere to the proper base 2 theory of metrics or do they use base 10 combos (i.e. the 1GB = 1000 MB)?
On Thu, 30 Mar 2000, Paquette, Trevor wrote:
Here we go..
A bit is the smallest unit of data in a computer; has a single binary value of either 0 or 1 A byte is a unit of information that is eight bits long. (half a byte, or 4 bits is called a nibble)
Computer storage is measured in byte multiples; which are based on powers of 2. Because humans deal mainly with the decimal system, the resulting number is usually 'rounded off' for humans to better comprehend.
1 Kbyte = 1024 bytes = 2^10 bytes = 1,024 bytes 1 Megabyte = 1024 Kbytes = 2^20 bytes = 1,048,576 bytes 1 Gigabyte = 1024 Mbytes = 2^30 bytes = 1,073,741,824 bytes 1 Terabyte = 1024 Gbytes = 2^40 bytes = 1,099,511,627,776 bytes 1 Petabyte = 1024 Tbytes = 2^50 bytes = 1,125,899,906,842,624 bytes 1 Exabyte = 1024 Pbytes = 2^60 bytes = 1,152,921,504,606,846,976 bytes = approx. 1 billion GB
-----Original Message----- From: Jay Orr [SMTP:orrjl@stl.nexen.com] Sent: Thursday, March 30, 2000 10:52 AM To: Karl Swartz Cc: toasters@mathworks.com Subject: Re: benchmark
Humm... Fun.. Do you know off hand how Solaris and netapp defines a MB or GB? In moving around files I started thinking about this, since depending on what tool you use you get file sizes in "bytes" "kbytes" "MB" or "GB" (a la gnu df, solaris df, etc...)
On Wed, 29 Mar 2000, Karl Swartz wrote:
Uh, if I can ask a simple (stupid?) question - I was looking at the
source
code for postmark and noticed this :
#define KILOBYTE 1024 #define MEGABYTE (1000*KILOBYTE)
Isn't a megabite 1024*1024?
It depends on who you ask. Long ago, disk vendors decided that they could make their disks look bigger if they defined MB to be 2000 sectors (assuming 512 byte sectors, or 8000 sectors for 128 byte sectors), and GB became 1000 MB. Of course they also talked about unformatted capacity to further inflate the size over reality.
In a similar vein, telco people talk about 1K = 1000. The 64K B- channel in an ISDN line is 64000 bits per second, not 65536.
I'm not sure about networking, but I think FDDI and 100base-T both have a data rate of 100 * 10^6 bits/second, not 100 * 2^20. (Not to be confused with the signalling rate, which as I recall is 125 * 10^6 for FDDI with some flavor of 4/5 encoding, and possibly something similar for 100base-T.)
What's right for Postmark? Good question. It looks like Jeff picked the standard for disk sizes, but it's not clear that's the standard most applicable to this case. Aren't standards wonderful? :-)
-- Karl Swartz Network Appliance Engineering Work: kls@netapp.com http://www.netapp.com/ Home: kls@chicago.com http://www.chicago.com/~kls/
Jay Orr Systems Administrator Fujitsu Nexion Inc. St. Louis, MO
----------- Jay Orr Systems Administrator Fujitsu Nexion Inc. St. Louis, MO
-
Jay Orr -
Paquette, Trevor