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Comment by walrus01 | Hacker News Reader

for comparison, write speed to RAM on DDR4-3200 is somewhere between 50000 to 60000MB/second on a fairly normal skylake workstation platform.

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Nope that’s more like cache write speed. Single-threaded sequential access to RAM is typically more like 10-15GB/s for current server CPUs: https://panthema.net/2013/pmbw/results.html - it’s true that workstation machines tend to have somewhat higher sequential throughout compared to the server-heavy list at that URL, but it’s more like 20GB/s, not 50-60.

RAM is not nessisarily single threaded. Unganged Dual / quad channel memory is effectively multithreaded. So really his numbers are real world even with CPU bottlenecks. https://www.techspot.com/news/62129-ddr3-vs-ddr4-raw-bandwid...

PS: DDR4-3200W in quad channel mode is crazy fast and should break 100GB/s though sill a long way from a 1080Ti 484 GB/s.

PCIe latency is probably the bigger issue.

This. Which is why Intel is working on Optane DIMMs.

Traversing the root complex can take upto 100 cpu cycles each way.

yep but Optane DIMM /NVDIMM is not for client product. It is on data center product list. Persistent Memory isn't just a concept on the textbook. It be realized now.

So was Optane at first and so were SSDs in general. DDR4 already has an optional spec for NVDIMMs, DDR5 will make it mandatory.

Please forget Optane, just think about intel persistent memory. If you really care about performance /latency.

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