4 ms·

> Now, let’s go back to that first hard drive, the IBM RAMAC from 1956. Here are some specs on that thing: > Storage Capacity: 3.75 MB > Cost: ~$9,200/terabyt

> Now, let’s go back to that first hard drive, the IBM RAMAC from 1956. Here are some specs on that thing: > Storage Capacity: 3.75 MB > Cost: ~$9,200/terabyte Those specs can't possibly be correct. If you multiply the cost by the storage, the cost of the drive works out to 3¢. This site[1] states, > It stored about 2,000 bits of data per square inch and had a purchase price of about $10,000 per megabyte So perhaps the specs should read $9,200 / megabyte? (Which would put the drive's cost at $34,500, which seems more plausible.) [1]: https://www.historyofinformation.com/detail.php?entryid=952 https://www.historyofinformation.com/detail.php?entryid=952

acdha 3y ago
https://en.m.wikipedia.org/wiki/IBM_305_RAMAC https://en.m.wikipedia.org/wiki/IBM_305_RAMAC has the likely source of the error: 30M bits (using the 6 data bits but not parity), but it rented for $3k per month so you didn’t have a set cost the same as buying a physical drive outright - very close to S3’s model, though.
- nijave 3y ago
  I think this is still IBMs license model (at least a few years ago). It was explained to me you basically license a certain amount of compute even though the hardware is in your data center and you pay overages if you exceed your licensed throughput. Since you license a fixed amount, there were projects at the company looking at running batch/non time sensitive jobs on the mainframe since it was effectively free off peak (I guess power cost was trivially compared to licensing).
  - mkesper 3y ago
    You had online jobs during the day and batch at night then. That's why you always had to have one night between. Obviously doesn't work when load is 24/7.
andywarfield 3y ago
oh shoot. good catch, thanks!
birdyrooster 3y ago
Must've put a decimal point in the wrong place or something. I always do that. I always mess up some mundane detail.
- S_A_P 3y ago
  Did you get the memo? Yeah I will go ahead and get you another copy of that memo.

acdha 3y ago

https://en.m.wikipedia.org/wiki/IBM_305_RAMAC https://en.m.wikipedia.org/wiki/IBM_305_RAMAC has the likely source of the error: 30M bits (using the 6 data bits but not parity), but it rented for $3k per month so you didn’t have a set cost the same as buying a physical drive outright - very close to S3’s model, though.

nijave 3y ago
I think this is still IBMs license model (at least a few years ago). It was explained to me you basically license a certain amount of compute even though the hardware is in your data center and you pay overages if you exceed your licensed throughput. Since you license a fixed amount, there were projects at the company looking at running batch/non time sensitive jobs on the mainframe since it was effectively free off peak (I guess power cost was trivially compared to licensing).
- mkesper 3y ago
  You had online jobs during the day and batch at night then. That's why you always had to have one night between. Obviously doesn't work when load is 24/7.

andywarfield 3y ago

oh shoot. good catch, thanks!

birdyrooster 3y ago

Must've put a decimal point in the wrong place or something. I always do that. I always mess up some mundane detail.

S_A_P 3y ago
Did you get the memo? Yeah I will go ahead and get you another copy of that memo.