1000x performance? 1000x relative to what? What's the actual figure we're looking at?
Seek time, there is a picture showing the seek times of different tech.
Only orders of magnitude.
Intel's roadmap for Optane SSDs with 1,000x performance
101–108 of 108 posts
Re: Intel's roadmap for Optane SSDs with 1,000x performance
#102Earlier quoted context omitted.
Consumer OS I/O software stacks are completely unable to deal with this. It was fine for spinning drive latency, it's okay(ish) for high-performance SSD but the open/read/write model just cannot work that fast. It's several orders of magnitude off. Assuming we keep the file system model, I'm guessing some kind of direct memory mapping is in order? Anyone knows what's ahead of us on the software side, to take advantag…
This is a great question. One way I imagine it: Short term, the disk controller becomes a peripheral on the memory bus. On a 64-bit x86-64 system, the top 16 bits of the address are either 0000 or ffff for RAM. Make it so that the prefix 1000 (for example) maps to the disk, so accessing (physical) address 1000000013371000 accesses byte 13371000 on the disk. Now processes can just ask the OS to perform a physical memo…
That's almost a weird amalgam of really old school computer architectures and new.
It seemed to me from the layperson descriptions of how the old tube-based systems were operated, some of the old architectures had no notion of files at all, it was all RAM all the time. I also read stories of when rotating media first started being used, programmers wrote data not sequentially on the media but in an optimized pattern so by the time the cpu pulled a value into RAM the read head was positioned multiple units over, and so data was written out according to the demands of the hardware, and now we're talking about taking the cpu out of most of the loop.
We aren't coming full circle with the new memory architectures we're exploring, but kind of a spiral in a "history doesn't repeat but rhymes" manner by dusting off some old techniques and putting new spins on them, pun not intended.
If always-persistent state becomes popular, then I wonder if that will revive the popularity of image-based environments, a la Smalltalk and Lisp Machines, along with the collaboration challenges those introduced.
Re: Intel's roadmap for Optane SSDs with 1,000x performance
#103gjulianm 20 hours ago
I'm curious, why do you say that the open/read/write model can't work? I suppose that current software should be optimized to take advantage of better performance, that is what really is.
Re: Intel's roadmap for Optane SSDs with 1,000x performance
#104To be perfectly clear: the 1000x claim isn't about throughput , but latency . The graph in the article makes this clear: spinning drives have latencies on the order of 10ms, NAND flash about 10us, and DRAM about 1ns. The claim is that Optane will achieve latencies on the order of 10ns, or 1000x better than NAND. The on-stage benchmark shows a write throughput of about 2GB/s, which is a much more modest improvement ov…
Consumer OS I/O software stacks are completely unable to deal with this. It was fine for spinning drive latency, it's okay(ish) for high-performance SSD but the open/read/write model just cannot work that fast. It's several orders of magnitude off. Assuming we keep the file system model, I'm guessing some kind of direct memory mapping is in order? Anyone knows what's ahead of us on the software side, to take advantag…
The main reason to keep it are: 1) network 2) what if we uncover a faster cpu/mem ? We would need to reintroduce file-systems. I'd say it's safe to deprecate it after about 30 years after it become obsolete. (So we are sure nothing will surpass it any time soon.)
Re: Intel's roadmap for Optane SSDs with 1,000x performance
#105so if you solder this accelerator onto a motherboard and make it a few times larger than your RAM, you get a super-low-latency L5-ish cache (where RAM is L4-ish) and, potentially, an ability to instantenously suspend and keep suspended without consuming any power at all, assuming RAM is mostly in the Optane cache at all times. sounds nice.
If it still suffers from the limited number of the write cycles, if it's even a few orders of magnitude more it still can't be used instead of RAM, but still just instead of the disk.
They claim that it has an unlimited number of write cycles.
Re: Intel's roadmap for Optane SSDs with 1,000x performance
#106Earlier quoted context omitted.
For consumer, and "online" hardware I fully agree, but were going to have tape for a long time to come. As a medium, for offline, offsite it still reigns king. Density, reliably, and durability remain high, vs platter based drives or SSD. I know of at least two companies that keep tape going for compliance reasons. At the end of each year, they do a pretty large archival snapshot, and send it off to storage. It will…
There are some interesting regulations in finance, I know at least one bank that keeps offline backups on tapes, but wonder how often do they test it. My experience with them tells me, they are not the most tech savvy bunch. If they ever need to use backups with the software they were provided decades ago / by modern fast failing agile company (according to taste), even if they can get the source it will be very hard…
> Reproducible builds is not exactly a solved problem.
Indeed, but we are getting there (over 90% of packages from Debian stretch amd64 and 99.9% of OpenWRT packages):
https://tests.reproducible-builds.org/debian/ https://tests.reproducible-builds.org/openwrt/
Re: Intel's roadmap for Optane SSDs with 1,000x performance
#107Earlier quoted context omitted.
To put these latency numbers in perspective 1ns is about 11 inches at the speed of light.
Or three cycles on a typical desktop CPU.
Yes, but even one round trip to the store could blow most of your latency budget. The store will have to be right next to the processor.
Re: Intel's roadmap for Optane SSDs with 1,000x performance
#108If SSDs and RAM reach the same speeds, could RAM become obsolete? If so, architecture of computers will change drastically.
If 3d Xpoint is cheaper, lower latency, and higher throughput than DRAM, yes, it will obsolete DRAM. Currently it is higher latency, and lower throughput. And it is cheaper on a per-GB basis, but with a much higher minimum GB (like, 128GB).
Even if it just cheaper and same order of magnitude latency, it'll likely take over. High end systems would still have DRAM as a large L4/LLC cache, while low end ones will omit it.