3 ms·

Today, compute speed is roughly 5-6 orders of magnitude faster (single threaded) than it was 30 years ago. Today, RAM is roughly 5-6 orders of magnitude faster

by brilee 4y ago

Today, compute speed is roughly 5-6 orders of magnitude faster (single threaded) than it was 30 years ago. Today, RAM is roughly 5-6 orders of magnitude faster than HDD was 30 years ago. All the old-school HDD-optimization techniques from traditional database programming, etc. are now fully relevant again for memory management.

Retric 4y ago
The access patterns are very different which makes old optimizations less useful. For example HDD latency was very sequential with the heads stacked on top of each other. Meanwhile modern memory has has latency for a single request but you can make several requests at the same time and latency doesn’t stack linearly.
- AnimalMuppet 4y ago
  The comparison is about speed, not total capacity. Sure, memory hasn't scaled like that. But in terms of CPU stalling, it's effectively the same as disk was.
  - Retric 4y ago
    I edited the point a few times trying to get the idea across, but the point was one of access patterns. Modern RAM allows paralleled access where HDD effectively only had a single read/wrote head. People also on average do a lot more computation on any given bit of memory.
monocasa 4y ago
> Today, compute speed is roughly 5-6 orders of magnitude faster (single threaded) than it was 30 years ago Wat? No it's not. It's closer to 5x-6x than it is to 5 orders of magnitude if you're looking at instructions the CPU normally executes. > All the old-school HDD-optimization techniques from traditional database programming, etc. are now fully relevant again for memory management. Those techniques were mainly managing the fact that it took 100s of milliseconds to random seek (like, human perceptible times to do one seek) so the algorithms tried hard to minimize that. It doesn't have much bearing on RAM with something like 100ns random access.
- dragonwriter 4y ago
  > It's closer to 5x-6x than it is to 5 orders of magnitude 1993 was when the original 60-66Mhz Pentium first shipped; 5 orders of magnitude may be an exaggeration, but every step since then has had of increases beyond just clock speed, and clock speed alone has increased nearly two orders of magnitude.
  - rasz 4y ago
    Memory latency went down mere 2x between SDR and DDR around 2000, and then stayed flat for the last 20 years: https://en.wikipedia.org/wiki/CAS_latency#Memory_timing_examples https://en.wikipedia.org/wiki/CAS_latency#Memory_timing_exam...
    - dragonwriter 4y ago
      > Memory latency The widening gap between memory latency vs speed of processing in the processor (and how that arguably makes access optinizations that used to make sense between processor and HDD sensible between processor and main memory) is the issue that was being discussed, so memory latency can't be counted as part of processor speed in that context.
  - monocasa 4y ago
    And I still reckon that it's closer to 5-6x than it is to 5or6 orders of magnitude.
    - dragonwriter 4y ago
      > And I still reckon that it’s closer to 5-6x than it is to 5or6 orders of magnitude. The geometric midpoint (the only one that makes sense here) between the high end of 5-6x and the low end of 5-6 orders of magnitude is about 774×. The best info I can find (unsurprisingly, direct comparisons of performance of long-separated-in-time processors in aggregate is hard to find) is that between 1995-2011, integer performance increased somewhere well over 128 times but less than 256 times and floating point significantly more than 256x, and was trending in the last several years of the period to increase at a pace of 21% per year for both. [0] Seems likely to be close to or significantly past the 774× level between 1993-2023. [0] https://preshing.com/20120208/a-look-back-at-single-threaded-cpu-performance/ https://preshing.com/20120208/a-look-back-at-single-threaded...
rbanffy 4y ago
> All the old-school HDD-optimization techniques Kind of. With memory, at least, we don't need to do elevator seeks.

by brilee 4y ago

Retric 4y ago

The access patterns are very different which makes old optimizations less useful. For example HDD latency was very sequential with the heads stacked on top of each other. Meanwhile modern memory has has latency for a single request but you can make several requests at the same time and latency doesn’t stack linearly.

AnimalMuppet 4y ago
The comparison is about speed, not total capacity. Sure, memory hasn't scaled like that. But in terms of CPU stalling, it's effectively the same as disk was.
- Retric 4y ago
  I edited the point a few times trying to get the idea across, but the point was one of access patterns. Modern RAM allows paralleled access where HDD effectively only had a single read/wrote head. People also on average do a lot more computation on any given bit of memory.

monocasa 4y ago

> Today, compute speed is roughly 5-6 orders of magnitude faster (single threaded) than it was 30 years ago Wat? No it's not. It's closer to 5x-6x than it is to 5 orders of magnitude if you're looking at instructions the CPU normally executes. > All the old-school HDD-optimization techniques from traditional database programming, etc. are now fully relevant again for memory management. Those techniques were mainly managing the fact that it took 100s of milliseconds to random seek (like, human perceptible times to do one seek) so the algorithms tried hard to minimize that. It doesn't have much bearing on RAM with something like 100ns random access.

dragonwriter 4y ago
> It's closer to 5x-6x than it is to 5 orders of magnitude 1993 was when the original 60-66Mhz Pentium first shipped; 5 orders of magnitude may be an exaggeration, but every step since then has had of increases beyond just clock speed, and clock speed alone has increased nearly two orders of magnitude.
- rasz 4y ago
  Memory latency went down mere 2x between SDR and DDR around 2000, and then stayed flat for the last 20 years: https://en.wikipedia.org/wiki/CAS_latency#Memory_timing_examples https://en.wikipedia.org/wiki/CAS_latency#Memory_timing_exam...
  - dragonwriter 4y ago
    > Memory latency The widening gap between memory latency vs speed of processing in the processor (and how that arguably makes access optinizations that used to make sense between processor and HDD sensible between processor and main memory) is the issue that was being discussed, so memory latency can't be counted as part of processor speed in that context.
- monocasa 4y ago
  And I still reckon that it's closer to 5-6x than it is to 5or6 orders of magnitude.
  - dragonwriter 4y ago
    > And I still reckon that it’s closer to 5-6x than it is to 5or6 orders of magnitude. The geometric midpoint (the only one that makes sense here) between the high end of 5-6x and the low end of 5-6 orders of magnitude is about 774×. The best info I can find (unsurprisingly, direct comparisons of performance of long-separated-in-time processors in aggregate is hard to find) is that between 1995-2011, integer performance increased somewhere well over 128 times but less than 256 times and floating point significantly more than 256x, and was trending in the last several years of the period to increase at a pace of 21% per year for both. [0] Seems likely to be close to or significantly past the 774× level between 1993-2023. [0] https://preshing.com/20120208/a-look-back-at-single-threaded-cpu-performance/ https://preshing.com/20120208/a-look-back-at-single-threaded...

rbanffy 4y ago

> All the old-school HDD-optimization techniques Kind of. With memory, at least, we don't need to do elevator seeks.