4 ms·
Yes, DDR3 is the lowest CAS latency and lasts ALOT longer. Just like SSDs from 2010 have 100.000 writes per bit instead of below 10.000. CPUs might even follo
by bullen 11mo ago
Yes, DDR3 is the lowest CAS latency and lasts ALOT longer.
Just like SSDs from 2010 have 100.000 writes per bit instead of below 10.000.
CPUs might even follow the same durability pattern but that remains to be seen.
Keep your old machines alive and backed up!
- mrob 11mo agoCAS latency is specified in cycles and clock rates are increasing, so despite the number getting bigger there's actually been a small improvement in latency with each generation.
- bullen 11mo agoNot for small amounts of data. Bandwith increases, but if you only need a few bytes DDR3 is faster. Also slower speed means less heat and longer life. You can feel the speed advantage by just moving the mouse on a DDR3 PC...
- mrob 11mo agoRAM latency doesn't affect mouse response in any perceptible way. The fastest gaming mice I know of run at 8000Hz, so that's 125000ns between samples, much bigger than any CAS latency. And most mice run substantially slower. Maybe your old PC used lower-latency GUI software, e.g. uncomposited Xorg instead of Wayland.
- bullen 11mo agoI only felt it on Windows, maybe tht is due to the special USB mouse drivers Microsoft made? Still motion-to-photon latency is really lower on my DDR3 PCs, would be cool to know why.
- CyberDildonics 11mo agoYou are conflating two things that have nothing to do with each other. Computers have had mice since the 80s. Still motion-to-photon latency is really lower on my DDR3 PCs, would be cool to know why. No it isn't, your computer is doing tons of stuff and the cursor on windows is a hardware feature of the graphics card. Should I even ask why you think memory bandwidth is the cause of mouse latency?
- Fnoord 11mo agoDan Luu actually measured latency of older computers (terminal, input latency), and compared it to modern computers. It shows older computers (and I mean previous century-wise old) have lower input latency. This is much more interesting than 'feelings', especially when discussing with other people.
- kbolino 11mo agoWhile it has nothing to do with how responsive your mouse feels, as that is measured in milliseconds while CAS latency is measured in nanoseconds, there has indeed been a small regression with DDR5 memory compared to the 3 previous generations. The best DDR2-4 configurations could fetch 1 word in about 6-7 ns while the best DDR5 configurations take about 9-10 ns. https://en.wikipedia.org/wiki/CAS_latency#Memory_timing_examples https://en.wikipedia.org/wiki/CAS_latency#Memory_timing_exam...
- hajile 11mo agoCAS latency doesn't matter so much as ns of total random-access latency and the raw clockspeed of the individual RAM cells. If you are accessing the same cell repeatedly, RAM hasn't gotten faster in years (around DDR2 IIRC).
- 0manrho 11mo ago> 100.000 writes per bit per cell* Also, that SSD example is wildly untrue. Especially with the context of available capacity at the time. You CAN get modern SSD's with mind boggling write endurance per cell, AND has multides more cells, resulting in vastly more durable media than what was available pre 2015. The one caveat there to modern stuff being better than older stuff is Optane (the enterprise stuff like the 905P or P5800X, not that memory and SSD combo shitshow that Intel was shoveling out the consumer door). We still haven't reached parity with the 3DXpoint stuff, and it's a damn shame Intel hurt itself in it's confusion and cancelled that, because boy would they and Micron be printing money hand over fist right now if they were still making them. Still, Point being: Not everything is a TLC/QLC 0.3DWPD disposable drive like has become standard in the consumer space. If you want write endurance, capacity, and/or performance, you have more and better options today than ever before (Optane/3DXPoint excepted). Regarding CPU's, they still follow that durability pattern if you unfuck what Intel and AMD are doing with boosting behavior and limit them to perform with the margins that they used to "back in the day". This is more of a problem on the consumer side (Core/Ryzen) than the enterprise side (Epyc/Xeon). It's also part of why the OC market is dying (save for maybe the XOC market that is having fun with LN2), those CPU's (especially consumer ones) come from the factory with much less margin for pushing things, because they're already close to their limit without exceedingly robust cooling. I have no idea what the relative durability of RAM is tbh, it's been pretty bulletproof in my experience over the years, or at least bulletproof enough for my usecases that I haven't really noticed a difference. Notable exception is what I see in GPU's, but that is largely heat-death related and often a result of poor QA by the AIB that made it (eg, thermal pads not making contact with the GDDR modules).
- bullen 11mo agoMaybe but in my experience a good old <100GB SSD from 2010-14 will completely demolish any >100GB from 2014+ in longevity. Some say they have the opposite experience, mine is ONLY Intel drives, maybe that is why. X25-E is the diamond peak of SSDs probably forever since the machines to make 45nm SLC are gone.
- zozbot234 11mo ago
- Aurornis 11mo ago> Yes, DDR3 is the lowest CAS latency and lasts ALOT longer. DDR5 is more reliable. Where are you getting this info that DDR3 lasts longer? DDR5 runs at lower voltages, uses modern processes, and has on-die ECC. This is already showing up in reduced failure rates for DDR5 fleets: https://ieeexplore.ieee.org/document/11068349 https://ieeexplore.ieee.org/document/11068349 The other comment already covered why comparing CAS latency is misleading. CAS latency is measured in clock cycles. Multiply by the length of a clock cycle to get the CAS delay.
- rasz 11mo agoIt has on-die ECC _because_ it is so unreliable. ECC is there to fix its terribleness from factory.
- Aurornis 10mo agoSo? If the net result is more reliable memory, it doesn't matter. Many things in electrical engineering use ECC on top of less reliable processes to produce a net result that is more reliable on the whole. Everything from hard drives to wireless communication. It's normal.
- rasz 10mo agoECC doesnt completely fix it, it only masks problems for most common use patterns. Rowhammer is a huge problem.
- ahartmetz 10mo agoJust like increasing the structure size "only" decreases the likelihood of bit flips. Correcting physical unreliability with more logic may feel flimsy, but in the end, probabilities are probabilities.
- Fnoord 11mo agoOld machines use a lot more power (worse nm), and DDR5 has equivalent to ECC, while previously you had to specifically get ECC RAM and it wouldn't work on cheaper Intel hardware (bulk of old hardware is going to be Intel).
- account42 11mo agoThe on-chip ECC in DDR5 is there to account for lower reliability of the chips themselves at the higher speeds. It does NOT replace dedicated ECC chips which cover a whole lot more.