3 ms·

> the performance difference is minuscule I thought DDR5 brought a 2× increase in throughput? It didn't help that much, it seems?

InvaderFizz 5y ago
The timings on DDR5 are very loose right now. Don't expect much real gains for another year or two as it matures. If you have a specific task that is extremely memory bandwidth constrained, it's great. But then again, you are probably looking at something with 8 channels if it is that big of an issue to you.
- jquery 5y ago
  I'm using 8-channel DDR4-3200. Would I get any benefit from 4-channel DDR5-5xxx? Is 8-channel DDR4-3200 roughly equivalent to 4-channel DDR4-6400, or am I missing something?
  - InvaderFizz 5y ago
    You're not missing much. Alder Lake (2ch DDR5-4800) achieved pretty impressive memory bandwidth, but it is still eclipsed by 4ch DDR4-3200 on Threadripper. If you could get 2ch DDR5-6400, it would be the same bandwidth as the TR4. What I don't understand well enough to know the impacts, is how latency plays into specific workloads. 2ch Alder lake is about 70GB/s[0] 4ch Threadripper is about 85GB/s 8ch/64c Threadripper Pro/Epyc is about 140GB/s[1] 0: https://hothardware.com/reviews/intel-12th-gen-core-alder-lake-cpu-review?page=2 https://hothardware.com/reviews/intel-12th-gen-core-alder-la... 1: https://www.anandtech.com/show/16805/amd-threadripper-pro-review-an-upgrade-over-regular-threadripper/8 https://www.anandtech.com/show/16805/amd-threadripper-pro-re...
kllrnohj 5y ago
It's less than 2x when you factor in the mature DDR4 that greatly exceeds jedec specs vs. the immature ddr5 that's sort of at bare minimum. Eventually ddr5 will outpace DDR4, but right now it's the awkward transition time. Not unlike early DDR4 vs. ddr3
redisman 5y ago
Eventually yes but the kits available right now are not very impressive. Early adopter tax definitely. You’ll probably get at least 2x faster memory kits eventually, I’m not sure how high DDR5 can scale
Dylan16807 5y ago
Memory throughput doesn't have a huge impact on performance in most desktop scenarios, and right now DDR4 is easily 3600MHz while DDR5 is 4800/5200. 4800MHz DDR4 even seems to be cheaper than 4800MHz DDR5.

InvaderFizz 5y ago

The timings on DDR5 are very loose right now. Don't expect much real gains for another year or two as it matures. If you have a specific task that is extremely memory bandwidth constrained, it's great. But then again, you are probably looking at something with 8 channels if it is that big of an issue to you.

jquery 5y ago
I'm using 8-channel DDR4-3200. Would I get any benefit from 4-channel DDR5-5xxx? Is 8-channel DDR4-3200 roughly equivalent to 4-channel DDR4-6400, or am I missing something?
- InvaderFizz 5y ago
  You're not missing much. Alder Lake (2ch DDR5-4800) achieved pretty impressive memory bandwidth, but it is still eclipsed by 4ch DDR4-3200 on Threadripper. If you could get 2ch DDR5-6400, it would be the same bandwidth as the TR4. What I don't understand well enough to know the impacts, is how latency plays into specific workloads. 2ch Alder lake is about 70GB/s[0] 4ch Threadripper is about 85GB/s 8ch/64c Threadripper Pro/Epyc is about 140GB/s[1] 0: https://hothardware.com/reviews/intel-12th-gen-core-alder-lake-cpu-review?page=2 https://hothardware.com/reviews/intel-12th-gen-core-alder-la... 1: https://www.anandtech.com/show/16805/amd-threadripper-pro-review-an-upgrade-over-regular-threadripper/8 https://www.anandtech.com/show/16805/amd-threadripper-pro-re...

kllrnohj 5y ago

It's less than 2x when you factor in the mature DDR4 that greatly exceeds jedec specs vs. the immature ddr5 that's sort of at bare minimum. Eventually ddr5 will outpace DDR4, but right now it's the awkward transition time. Not unlike early DDR4 vs. ddr3

redisman 5y ago

Eventually yes but the kits available right now are not very impressive. Early adopter tax definitely. You’ll probably get at least 2x faster memory kits eventually, I’m not sure how high DDR5 can scale

Dylan16807 5y ago

Memory throughput doesn't have a huge impact on performance in most desktop scenarios, and right now DDR4 is easily 3600MHz while DDR5 is 4800/5200. 4800MHz DDR4 even seems to be cheaper than 4800MHz DDR5.