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Intel's roadmap for Optane SSDs with 1,000x performance

computerworld.com

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Re: Intel's roadmap for Optane SSDs with 1,000x performance

#91

Post by nneonneo »

imtringued wrote: post #82
nneonneo wrote: post #61

Earlier quoted context omitted.

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…

>Suddenly "serialization" to disk is no longer required That's not true. You'd still want excel to just save your sheets as xls file and show it to a coworker as opposed to sharing the entire excel program state. Upgrading from one version to another also requires a stable persistent data format for things such as configurations. Not to mention that you still need serialization to communicate over a network.

Yes, you're definitely right - "serialization" as a concept is going to still be needed for data interchange. I just didn't want to mention it because that's just status quo, not part of the new computing model.

In my original comment, I simply meant that you would no longer have to serialize your data to your own disk.

Re: Intel's roadmap for Optane SSDs with 1,000x performance

#92

Post by johnm1019 »

daveguy wrote: post #41
olavgg wrote: post #15

Earlier quoted context omitted.

Basically on a PCIe 3.0 x4 maximum performance is 4000GB/s, in practice this is 3200-3500MB/s. With 4k random write, you will get maximum 800.000 to 875.000 iops per second. Consumer-grade SSD's barely manage to write 500-1000 iops when sending the ATA_CMD_FLUSH command unless they are lying which is really bad. Good read about consumer SSD performance: http://www.sebastien-han.fr/blog/2014/10/10/ceph-how-to-test...

nitpick: iops is I/O operations per second. iops per second is redundant -- would be like FLOPS per second.

and I still use ATM machines....

Re: Intel's roadmap for Optane SSDs with 1,000x performance

#93

Post by gpderetta »

jdub wrote: post #77
gpderetta wrote: post #46

Earlier quoted context omitted.

Or a way to make system calls faster, some sort of vdso with the ability to switch privilege level.

That's how __vsyscall works now.

__vsyscall simply abstracts away the actual system call invocation strategy (int, sysenter, syscall), but doesn't change the model at all.

Anyway, what I was thinking was similar to call gates, which were phased out for being slow. Probably just making syscall faster in the CPU and reducing the overhead kernel side would be enough.

Re: Intel's roadmap for Optane SSDs with 1,000x performance

#94

Post by sspiff »

ChuckMcM wrote: post #67
nneonneo wrote: post #21

To 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…

Ok, a couple of things. First, I found it really amazing at how convoluted Intel plotted their numbers on that latency graph so that it would "Up and to the right" which everyone "knows" is good. The second thing is that Intel has been claiming multiple GB/second of throughput as well. They really do believe this will be a replacement for DRAM on some platforms. As in you read into your L3 case from this stuff and yo…

> What that means is a laptop that can turn it self off between waiting for sectors to read in from the disk or packets to come off the network, or keys to be pressed by the user.

Yeah, no. It might be able to turn of the CPU, but everything else would have to keep running. Graphics hardware does not deal well with frequent state changes. Network hardware would still need to run to keep its clock in sync with the signal.

So, you get to turn off a handful of components, which is where we already are today - CPUs spend most of their time in deep sleep states. USB devices and chipsets implement sleep states. Graphics hardware clocks down significantly.

Re: Intel's roadmap for Optane SSDs with 1,000x performance

#95

Post by lorenzhs »

loeg wrote: post #14
nashashmi wrote: post #3

If 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).

I don't think that it's intended to replace DRAM. It's going to be cheaper than DRAM (price-wise, I expect DRAM / 3DXpoint ≈ 3DXpoint / NAND), but significantly higher latency (the article says an order of magnitude, but those figures don't seem to include bus stuff etc, so it might be a bit more. Total latency will likely be in the range of a few hundred nanoseconds). That, and the limited durability (much higher than NAND, but still limited).

I think this is going to be amazing for "in-memory" data bases: it's cheaper, still very fast, has higher capacity and is persistent (the article doesn't even mention that). But it won't replace DRAM any time soon imho.

Re: Intel's roadmap for Optane SSDs with 1,000x performance

#96

Post by a_imho »

zer00eyz wrote: post #43
jacquesm wrote: post #29

Earlier quoted context omitted.

It's a game changer either way, and it will be one more nail in the coffin of anything mechanical.

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 to compile and run them. Reproducible builds is not exactly a solved problem.

Re: Intel's roadmap for Optane SSDs with 1,000x performance

#97

Post by Unklejoe »

nneonneo wrote: post #21

To 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…

I wonder what the actual latency improvements will be. If it's connected through PCI express, there will be a lower limit which is dictated by the bus. While reducing the latency of the drive will still certainly matter, this latency introduced by the bus will serve to lessen the relative improvements with respect to SSDs.

PCI Express is packetized and it takes a little over 1 nanosecond per byte for the 3.0 version. I believe the minimum packet size is 20 bytes, but I'm not positive on that. It seems like the latency could never be less than 2 * (1 * 20) nanoseconds in the case of a random access, and this is before the latency of the drive itself is factored in. Surely there will be a few clock cycles required for the drive HW to decode the PCIe transaction and act upon it.

That being said, any latency improvement of the drive _will_ have a direct reduction in effective latency in the end, so it’s all good news to me. I’m just curious about the 1000x figure that’s being referenced everywhere.

Re: Intel's roadmap for Optane SSDs with 1,000x performance

#98

Post by y4mi »

a_imho wrote: post #96
zer00eyz wrote: post #43

Earlier 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…

they need to put their entire environment into docker container and archive the images! theyll be able to recreate their whole environment at any time in the future!

...ill see myself out

Re: Intel's roadmap for Optane SSDs with 1,000x performance

#99

Post by bluecalm »

1024core wrote: post #24
bluecalm wrote: post #16

So your run of the mill SSD these days is like 500MB/s. Dual channel RAM @ 1600Mhz with 64bit bus is: 2 * 8bytes * 1 600 000 000 = 25.6GB/sec 500MB 1000x faster would be 500GB/sec or about 20x faster than standard RAM. That puts the claim in perspective :)

You're talking throughput. They're talking latency.

Yeah, I had a blind spot here. It's just throughput is all that matters for things I am doing so it didn't occur to me "performance" claims might about latency. Thanks for pointing that out.
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