4 ms·

Almost all workloads are memory bw constrained, is the problem of our era. That is one of the biggest drivers of M1 perf across the board. Optane is orders of

Almost all workloads are memory bw constrained, is the problem of our era. That is one of the biggest drivers of M1 perf across the board. Optane is orders of magnitude faster than virtual memory, it is a complete OS bypass. I think you are conflating Optane used in an SSD and Optane on the memory bus. SSD Optane was a way to package and sell it before the rest of the hardware and sofware caught up for DIMM based Optane. edit, removed snark.

smoldesu 4y ago
> Almost all workloads are memory bw constrained, is the problem of our era. Well, sure; I think that sentiment applies to networking/CPU maximization too. But, much like we discovered with SSDs, there is a point of diminishing return for most people. Pretty much anything running an NVMe SSD won't experience significant storage throttling. Anyone connected to wired broadband will have roughly the same experience as everyone else on it. Since so much software is designed around nominal specifications, I don't really notice the M1's memory bandwidth in regular use. Text editing, app launching, smoothness and usability... it's all roughly the same as my throwaway $300 Thinkpad that has a nicer keyboard and no ARM contrivances. > Optane is orders of magnitude faster than virtual memory Not really... Intel has only claimed that Optane is 3-4 times faster than flash-based NVMe, which still puts it at >10x slower than the speeds of a trashy DDR4 2133mHz DIMM. If it's supposed to replace memory, it's both slower and more expensive. If it's intended to be a storage volume, most people would probably get better performance out of a ramfs or tempfs.
- sitkack 4y ago
  > Intel has only claimed that Optane is 3-4 times faster than flash-based NVMe Which you can't talk to directly, you have to traverse OS and the cache. Optane sits directly on the memory bus, reads and writes can bypass the OS completely. We aren't talking about the same things. It sounds like there is something wrong with your M1. https://swanson.ucsd.edu/data/bib/pdfs/2019arXiv-AEP.pdf https://swanson.ucsd.edu/data/bib/pdfs/2019arXiv-AEP.pdf

smoldesu 4y ago

> Almost all workloads are memory bw constrained, is the problem of our era. Well, sure; I think that sentiment applies to networking/CPU maximization too. But, much like we discovered with SSDs, there is a point of diminishing return for most people. Pretty much anything running an NVMe SSD won't experience significant storage throttling. Anyone connected to wired broadband will have roughly the same experience as everyone else on it. Since so much software is designed around nominal specifications, I don't really notice the M1's memory bandwidth in regular use. Text editing, app launching, smoothness and usability... it's all roughly the same as my throwaway $300 Thinkpad that has a nicer keyboard and no ARM contrivances. > Optane is orders of magnitude faster than virtual memory Not really... Intel has only claimed that Optane is 3-4 times faster than flash-based NVMe, which still puts it at >10x slower than the speeds of a trashy DDR4 2133mHz DIMM. If it's supposed to replace memory, it's both slower and more expensive. If it's intended to be a storage volume, most people would probably get better performance out of a ramfs or tempfs.

sitkack 4y ago
> Intel has only claimed that Optane is 3-4 times faster than flash-based NVMe Which you can't talk to directly, you have to traverse OS and the cache. Optane sits directly on the memory bus, reads and writes can bypass the OS completely. We aren't talking about the same things. It sounds like there is something wrong with your M1. https://swanson.ucsd.edu/data/bib/pdfs/2019arXiv-AEP.pdf https://swanson.ucsd.edu/data/bib/pdfs/2019arXiv-AEP.pdf