4 ms·

> RAM 15 years ago was designed completely differently, and had considerably lower capabilities in terms of storage and latency. You got that backwards, chief.

> RAM 15 years ago was designed completely differently, and had considerably lower capabilities in terms of storage and latency. You got that backwards, chief. RAM latencies have increased tremendously over the last 15 years.

namibj 5y ago
Actual latency has improved, but clock-relative latency hasn't. So what?
- beebeepka 5y ago
  No, actual latencies have been climbing since ddr2. Thanks for the downvote though
  - njibhu 5y ago
    This article from Crucial probably explains the two arguments: https://www.crucial.com/articles/about-memory/difference-between-speed-and-latency https://www.crucial.com/articles/about-memory/difference-bet... But their conclusion is that practical latency has indeed decreased over the last 15 years.
    - beebeepka 5y ago
      After looking at the table, I am ready to swallow my pride. Looks like practical latencies have changed a tiny bit. So me and the person I replied to originally were both wrong
      - namibj 5y ago
        Also note that practical non-high-capacity DDR4 setups reach 3600 CL16. That's way faster than the 3200 CL22 they gave at the bottom.
      - formerly_proven 5y ago
        You were wrong about the memory latency¹ increasing, but the memory latency² has increased (substantially) for most systems, while the memory latency³ has indeed decreased. In general, the memory latency¹ has not improved much. Of course, the memory latency⁴ has greatly increased, due to the clock frequency being increased so much to enable the higher bandwidth, while the memory latency¹ stayed mostly the same. [1] as in: access latency of the DRAM [2] as in: how long does a CPU memory read which is _not_ cached take [3] as in: how long does a CPU memory read on average take [4] as in: CL
      - staticassertion 5y ago
        No, I was right. Not that it matters, feel free to replace latency with bandwidth. Or replace it with nothing and focus on capacity. It's a blip on my point, which is that the architecture has changed considerably to allow for progress in other areas.

namibj 5y ago

Actual latency has improved, but clock-relative latency hasn't. So what?

beebeepka 5y ago
No, actual latencies have been climbing since ddr2. Thanks for the downvote though
- njibhu 5y ago
  This article from Crucial probably explains the two arguments: https://www.crucial.com/articles/about-memory/difference-between-speed-and-latency https://www.crucial.com/articles/about-memory/difference-bet... But their conclusion is that practical latency has indeed decreased over the last 15 years.
  - beebeepka 5y ago
    After looking at the table, I am ready to swallow my pride. Looks like practical latencies have changed a tiny bit. So me and the person I replied to originally were both wrong
    - namibj 5y ago
      Also note that practical non-high-capacity DDR4 setups reach 3600 CL16. That's way faster than the 3200 CL22 they gave at the bottom.
    - formerly_proven 5y ago
      You were wrong about the memory latency¹ increasing, but the memory latency² has increased (substantially) for most systems, while the memory latency³ has indeed decreased. In general, the memory latency¹ has not improved much. Of course, the memory latency⁴ has greatly increased, due to the clock frequency being increased so much to enable the higher bandwidth, while the memory latency¹ stayed mostly the same. [1] as in: access latency of the DRAM [2] as in: how long does a CPU memory read which is _not_ cached take [3] as in: how long does a CPU memory read on average take [4] as in: CL
    - staticassertion 5y ago
      No, I was right. Not that it matters, feel free to replace latency with bandwidth. Or replace it with nothing and focus on capacity. It's a blip on my point, which is that the architecture has changed considerably to allow for progress in other areas.