4 ms·

The best part is how this will make your disc slower to use afterwards. The blocks are normally stored out of order, so that the time it takes to send the data

The best part is how this will make your disc slower to use afterwards. The blocks are normally stored out of order, so that the time it takes to send the data to the computer is about the same as the time it takes for the next block to show up under the drive’s read head.

gugagore 8y ago
https://en.wikipedia.org/wiki/Interleaving_(disk_storage) https://en.wikipedia.org/wiki/Interleaving_(disk_storage) for the curious
Zenst 8y ago
Ah the times when disc interleaving was something you could tune and see the difference in speed gain. Least early PC's that was a factor and https://en.wikipedia.org/wiki/SpinRite https://en.wikipedia.org/wiki/SpinRite was born and loved by all back then.
- ansible 8y ago
  Reading that Wikipedia article... I'm surprised SpinRite is still around. It is my understanding that modern magnetic media really hides what's going on at the platter level. This is not like the old days with MFM or RLL hard drives (before IDE). It is my understanding the modern disk controllers maintain their own mappings, and can in fact remap bad sectors on their own. I didn't think any of this information was available at the operating system level to the extent that it can be usefully modified outside the drive's own logic.
  - londons_explore 8y ago
    Modern drives do a bit of remapping, but still keep a near 1:1 mapping of physical to logical sectors. It surprises me, because the drive has much more knowledge of typical access patterns combined with the hardware characteristics, so could easily do things like store two copies of some data so that whichever is closest to the read head can be read. I guess manufacturers just aren't interested in speed optimizations anymore now that SSD's exist.
Yuioup 8y ago
So if you can space out the data so that the blocks line up perfectly to the spin cycle ... would that help?
- codeflo 8y ago
  Yeah, that was a well-known technique at the time. 8-bit optimization was really something special. It’s crazy how much performance people got out of those tiny machines by figuring out all of these little tricks.
  - vidarh 8y ago
    Reminds me of the Story of Mel: https://groups.google.com/forum/#!topic/net.jokes/k2JVKQzJSpY https://groups.google.com/forum/#!topic/net.jokes/k2JVKQzJSp... (also https://en.wikipedia.org/wiki/The_Story_of_Mel https://en.wikipedia.org/wiki/The_Story_of_Mel for background)

gugagore 8y ago

https://en.wikipedia.org/wiki/Interleaving_(disk_storage) https://en.wikipedia.org/wiki/Interleaving_(disk_storage) for the curious

Zenst 8y ago

Ah the times when disc interleaving was something you could tune and see the difference in speed gain. Least early PC's that was a factor and https://en.wikipedia.org/wiki/SpinRite https://en.wikipedia.org/wiki/SpinRite was born and loved by all back then.

ansible 8y ago
Reading that Wikipedia article... I'm surprised SpinRite is still around. It is my understanding that modern magnetic media really hides what's going on at the platter level. This is not like the old days with MFM or RLL hard drives (before IDE). It is my understanding the modern disk controllers maintain their own mappings, and can in fact remap bad sectors on their own. I didn't think any of this information was available at the operating system level to the extent that it can be usefully modified outside the drive's own logic.
- londons_explore 8y ago
  Modern drives do a bit of remapping, but still keep a near 1:1 mapping of physical to logical sectors. It surprises me, because the drive has much more knowledge of typical access patterns combined with the hardware characteristics, so could easily do things like store two copies of some data so that whichever is closest to the read head can be read. I guess manufacturers just aren't interested in speed optimizations anymore now that SSD's exist.

Yuioup 8y ago

So if you can space out the data so that the blocks line up perfectly to the spin cycle ... would that help?

codeflo 8y ago
Yeah, that was a well-known technique at the time. 8-bit optimization was really something special. It’s crazy how much performance people got out of those tiny machines by figuring out all of these little tricks.
- vidarh 8y ago
  Reminds me of the Story of Mel: https://groups.google.com/forum/#!topic/net.jokes/k2JVKQzJSpY https://groups.google.com/forum/#!topic/net.jokes/k2JVKQzJSp... (also https://en.wikipedia.org/wiki/The_Story_of_Mel https://en.wikipedia.org/wiki/The_Story_of_Mel for background)