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Comment by ksec | Hacker News Reader

They are mostly for Server / Database workload [1] and Facebook looked at reducing Memory usage with Optane[2].

Consumer workload see little to zero measurable benefits. Once you pass a certain Random Rd / Write speed, Seq Rd Write is still king, or likely not the source of bottlenecked.

[1] https://www.servethehome.com/intel-optane-hands-on-real-worl...

[2] https://research.fb.com/wp-content/uploads/2018/03/reducing-...

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What about developer workloads? Like reading hundreds of tiny files during compilation, writing thousands of tiny binary files after compilation, using disk-baked caches for IDE. I never found tests but for me it seems likely a scenario where Optane might help. Also things like starting a container or VM might be improved with Optane a little bit.

More RAM so your entire source tree is sitting in buffer cache is the way to go. The latency of hitting the SSD is way more than RAM, and for developer workloads (reading millions of tiny source code files to compile each one), latency is what matters.

You'll find often that these workloads are bottlenecked by network or CPU before they're slowed down by storage (especially the container and VM side). On compilation and IDE, is threaded I/O the most relevant way to think about those tasks? Phoronix has a threaded I/O benchmark that shows some significant increases in performance over other SSDs...

https://www.phoronix.com/scan.php?page=article&item=intel-op...

If that's not relevant though, how would you benchmark compilation and disk caching for IDE? I could perhaps try it myself...

That is a good question and I often thought the difference would be so small and the main bottleneck to be CPU, now thinking a bit more may be it is a premature assumption.

One possible way to test this out is if you have enough RAM and just fit everything inside a RAM drive, basically removing all I/O speed concern and see if there are any significant improvement.

The Optane SSDs do quite well on any random access benchmarks; they are kind of specialised for it. For sequential access however, high-end prosumer SSDs like the Samsung 970 Pro beat the Optanes.

Random access latency is the bottleneck. You can feel the difference between NAND and Optane even if your sequential speeds are comparable to a hard drive, let alone the 2 gigabytes per second those drives can push.

After all, if you have to wait 100 microseconds per 4K read, a single thread can only utilize 40 megabytes per second.

Agreed. I am just saying that the Optanes are specifically tuned to be the fastest storage drives for random access -- and they deliver on that front. There are benchmarks out there, I can send you a link if you like.

As an experiment I put two of them mirrored as L2Arc in front of an 6 drive SATA600 SSD (Samsung 860 Pro) ZFS array (zfs equivalent of raid 0+1) for PostgreSql / graph databases. It seems to help a bit for random access hits, but not as much as I hoped. Fancy devices though

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