Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Optane Memory – A bridge between DRAM and storage

intel.com

Post reply on HN
Print view View original

101–109 of 109 posts

Re: Optane Memory – A bridge between DRAM and storage

#101

Post by sitkack »

jandrese wrote: post #72
fgonzag wrote: post #59

Earlier quoted context omitted.

Except for the fact that it hits max throughput at way lower queue depths, is bit addressable, and it destroys mixed workloads since you can read while writing. I don't think it'll be revolutionary, but it will be quite nice for caching, databases, or even as a write cache using something like ZFS's zil, then flushing to NVMe SSDs

I don't know, that sounds like a pretty small niche at the end of the day. If it describes you workload I would jump on it ASAP because a year from now it will probably be discontinued.

It sounds like the cache layer to an SSD and should be internal, not a separate device.

Re: Optane Memory – A bridge between DRAM and storage

#102

Post by eyeinthepyramid »

sliken wrote: post #96
2bluesc wrote: post #20

Earlier quoted context omitted.

Interesting comment from Anandtech [0] > Keep in mind that consumer NVMe SSDs that boast throughput of 2GB/s or more generally do not reach their peak at low queue depth. Optane is supposed to be able to drive 1200MB/s read throughput at low queue depth (not sure why they listed QD4), so there is potential for some performance improvement here. Most consumer workloads never get out of low queue depth territory, so th…

Dunno, I find 1.2-1.6GB/sec on my samsung s950 all the time. The benchmarks I've seen do not show any noticeable difference between SATA and NVMe. Sure geeks like the idea of a lower head protocol, but truth is the protocol is not the bottlneck. Seems like Optane is a solution looking for a problem to fix. Normal M2 SATA's do fine: # dd if=/dev/sdb of=/dev/null bs=131072 1953586+1 records in 1953586+1 records out 256…

You're looking at throughput numbers, but Optane appears to be solving a iop / latency problem.

Re: Optane Memory – A bridge between DRAM and storage

#103

Post by dsr_ »

hoschicz wrote: post #92
dsr_ wrote: post #71

Earlier quoted context omitted.

Badly. Suppose you have a 16GB laptop and the 16GB optane. When you close your laptop to take it to a mid-morning meeting, you've just done a whole drive write. Do it again at lunch, twice in the afternoon and again when you get home, you're at 5 of your 6 drive writes. Now imagine you open your laptop 8 or 12 times a day...

Closing laptop usually mean suspend to memory, not disk.

Not in the regime Intel is proposing, because optane stores data without power like a disk.

Re: Optane Memory – A bridge between DRAM and storage

#104

Post by dv_dt »

sliken wrote: post #98
dv_dt wrote: post #30

Earlier quoted context omitted.

M.2 is a hardware connector. It can carry various flavors of SATA or NVMe over PCIe lanes. Generally M.2 drives will be at least equal to a SATA drive on a traditional SATA connector, with the potential to be much faster. However, even some of the m.2/NVMe drives which are much faster at the bus level seem to be bottlenecked by some design assumptions (both inside the drive and above in the various OS layers). I thin…

Just buy a nicer M2 and you get plenty of performance without special drivers: # dd if=/dev/sdb of=/dev/null bs=131072 1953586+1 records in 1953586+1 records out 256060514304 bytes (256 GB, 238 GiB) copied, 159.18 s, 1.6 GB/s

If you don't test read with some writing, you might be misled by performance of an SSD. 100% read or 100% write are very different from 50/50 or even 70/30 r/w. The mixed bandwidth typically drops by a lot. If you haven't pre-written some data, that dd test might not even be touching the flash. Just reading internal metadata...

But yes, nicer M.2s will perform better!

Re: Optane Memory – A bridge between DRAM and storage

#105

Post by amluto »

wtallis wrote: post #88
amluto wrote: post #57

I think you can (pending driver support?) plug one of these in and memory map it. On Linux, this means you'd see it as a "DAX" filesystem, and if you mmap(2) a file, you get a bona fide direct mapping of the hardware into your address space. This is very cool and would enable some interesting database-ish use cases. I'll believe it when I see the spec and the code.

No DAX yet. Both this consumer Optane Memory product and the enterprise Optane SSD announced last week are standard NVMe devices. For the enterprise market, Intel is providing mmap capability with a hypervisor-based software solution. 3D XPoint DIMMs are on the roadmap for next year.

That's lame. Some competitors are working on DAX-capable PCIe devices. Intel seems to be surprisingly behind here.

How would a hypervisor sulution work? Trap and emulate all accesses?

Re: Optane Memory – A bridge between DRAM and storage

#106

Post by ksec »

I think this is an Easy win for DIMM in servers where you could fit a much larger capacity then DRAM. And this is only a first gen product.

But for consumers? I am not sure if they can feel the difference between a decent SSD drive and Optane Memory. It fits the role of Page File. So you could always have 2x - 3x the Optane Memory as Page Cache. System with this would means less Memory required, and saves battery. While the controller for SSD could be less complicated and focus primarily on Seq/Read Write. SSD could also be DRAM-less, save cost and battery.

But even then, $44 for 16GB is just hard to convince most consumers.

Re: Optane Memory – A bridge between DRAM and storage

#108

Post by wtallis »

sliken wrote: post #96
2bluesc wrote: post #20

Earlier quoted context omitted.

Interesting comment from Anandtech [0] > Keep in mind that consumer NVMe SSDs that boast throughput of 2GB/s or more generally do not reach their peak at low queue depth. Optane is supposed to be able to drive 1200MB/s read throughput at low queue depth (not sure why they listed QD4), so there is potential for some performance improvement here. Most consumer workloads never get out of low queue depth territory, so th…

Dunno, I find 1.2-1.6GB/sec on my samsung s950 all the time. The benchmarks I've seen do not show any noticeable difference between SATA and NVMe. Sure geeks like the idea of a lower head protocol, but truth is the protocol is not the bottlneck. Seems like Optane is a solution looking for a problem to fix. Normal M2 SATA's do fine: # dd if=/dev/sdb of=/dev/null bs=131072 1953586+1 records in 1953586+1 records out 256…

You're not getting 1.6 GB/s out of a SATA drive that's communicating over a 600MB/s link. I think you may be confused about which products are using SATA vs PCIe.

Re: Optane Memory – A bridge between DRAM and storage

#109

Post by wtallis »

timothycrosley wrote: post #31
temuze wrote: post #12

Earlier quoted context omitted.

Looks faster than an SSD to me. From the FAQ: "Q4: Will Intel Optane memory also accelerate an SSD? If so how much? A: Yes. Intel Optane memory can be used to accelerate any type of SATA-based storage media, including SATA SSDs, However, the performance benefit of adding Intel Optane memory will be greater on slower storage devices like an HDD versus a relatively faster storage device like a SATA-SSD. Additional perf…

It's faster than SATA SSD but slower than most NVMe M.2 SSDs: http://www.anandtech.com/show/11227/intel-launches-optane-me... . Because of when this was launched, and the fact it only works with newer processors that also support NVMe, by the time it is at all common place, so would M.2 SSDs, making it a weird concept. It's essentially the most expensive per GB NVMe drive, with worse performance, and some software to…

Just FYI, there's no such thing as "processors that also support NVMe".

Intel's Windows-only caching software for the Optane Memory product will refuse to work on any but the newest Intel platforms, but any other caching software will work fine on any platform that supports PCIe. If it turns out that small Optane caches are worth what Intel's charging for the hardware, then the existing third-party caching solutions will get tuned to make full use of Optane.

Post reply on HN