7 ms·

The Evolution of Disk Storage and an Introduction to NVMe

92 points by workrockin 7y ago

3xblah 7y ago
Will the expression "spin up" ever fall out of usage?
- NikolaeVarius 7y ago
  Doubt it, though I don't think that I've used it in the context of SDD's recently since latency is that low. I think colloquially, it's pretty much understood to mean "time between turning on and being useful"
- modzu 7y ago
  language is symbolic so there doesn't have to be a literal connection between the reference and referent. for example you still "boot" a computer, which comes from the concept of "bootstrapping", ie, pulling oneself up by the straps of their boots. no boots are involved.
- bluedino 7y ago
  We 'spin up' virtual machines or instances now
  - NullPrefix 7y ago
    Because once you hit the launch button your mouse cursors starts spinning.
- jyrkesh 7y ago
  Contrary to what others said, it will likely fall out of favor the way the floppy icon faded for "Save" functionality in GUIs. It's everywhere until one day you realize you can't find it in any of the apps you use every day.
  - SketchySeaBeast 7y ago
    Doing a quick survey of the apps on my machine, it seems like most have just forgone the button altogether. For those that still have the button, the floppy icon seems to still be there.
    - Cthulhu_ 7y ago
      Yeah, purely from memory here but it's not that the save icon went out of fashion, but the concept of an icon bar or ribbon has gone; Microsoft's current UI standard for their native apps still has a ribbon IIRC, but I feel like that's one of the last vestiges. Using real world analogies went out the window after skeuomorphic design was no longer a thing too. Oddly enough, for me I had trouble adjusting to the 'folder' icon (or referring to folders as folders), we grew up with the term "directory" and I never had an association with anything physical with that.
  - vbezhenar 7y ago
    Latest Word: it's there; paint brush: check; paint.net: check; editpad: floppy. Even Intellij Idea uses floppy. Actually from a quick glance I did not find a single application which did not use floppy icon as a save pictogram. May be it's Mac world? Apple is eager to forget old ways.
- tyingq 7y ago
  It was in wide use for jet and turbine engines, centrifuges, gyroscopes, etc, before disk drives. I don't think it will fade away.
- niccl 7y ago
  At least one of the D's in the acronym usually means Disk, and there isn't a disk in many of these. Will that ever go, do you think?
spectramax 7y ago
I am surprised the article doesn't talk about Optane technology: https://en.wikipedia.org/wiki/3D_XPoint https://en.wikipedia.org/wiki/3D_XPoint
- Nursie 7y ago
  Is Optane really 'all that' compared to other PCIe storage? I know that Intel are positioning it as some sort of system accelerator, and I know it does tend to score well in comparisons... but not "This is in a completely different category" well, AFAICT. What's special about it compared to, for instance, Samsung's NVMe offerings?
  - sithadmin 7y ago
    Optane tends to crush the competition in terms of latency and random I/O, and mixed workload benchmarking. Samsung Z-NAND performs just slightly better on sequential I/O.
  - synack 7y ago
    Optane is persistent and bit-addressable, with mean latency under 1 microsecond, which is an order of magnitude faster than other SSDs. I don't think the market has figured out the right use case for Optane yet. The majority of desktop applications won't benefit from lower latency IOPS and it's too expensive to use for general purpose storage on servers. It does make sense for constant write or seek-heavy applications like database journals, but most databases are optimized for doing bulk sequential reads/writes and won't take advantage of Optane's bit addressable storage. Intel's recently started shipping Optane DIMM modules that act like slow, cheap, high density RAM. This is an interesting option as it allows in-memory databases to be atomically persistent without having to add any code.
    - wtallis 7y ago
      > This is an interesting option as it allows in-memory databases to be atomically persistent without having to add any code. It isn't quite that simple. To start with, you need either a cache line flush or cache line writeback instruction to get you data out to persistent storage. And the Optane DIMMs currently are used in one of two modes: as transparent expansion of DRAM or as separately addressed and managed storage. In the DRAM-like mode, the system's actual DRAM is used as a cache, and the Optane storage does not persist across reboots. In the storage mode, you need extra code to access it, though you can treat it as simply a block device instead of using special-purpose persistent memory programming interfaces.
edoo 7y ago
I use LVM and have enough storage that all SSD would be a little expensive so for the last few years I've been using the block caching LVM feature with mirrored NVME drives as a writeback cache to my large HDD array. It greatly increases the performance of the storage with little hassle. If haven't played with gluster for a few years but it has a tiered storage feature so the most recently used files actually get moved onto the high speed storage medium, which depending on your workloads might be even better, assuming gluster is now performent and stable enough.
brianpaul 7y ago
FWIW, I believe Cray had an SSD option for the X-MP back in the early 80s.
- theideaofcoffee 7y ago
  They sure did! It came in 256-, 512- and 1024-MB flavors, if i recall, in its own cabinet off to the side at a blazing 1000MB/s. I don’t have a hunk of the SSD, but I have a (30lb) board of the central memory perched against my desk right now.
- wolf550e 7y ago
  From the brochure, it had a few million of 64-bit words worth of RAM that was used as regular RAM ("central memory") and a lot more of ECC DRAM that was used as fast storage ("SSD"). What was the API for the SSD? Was it mapped into virtual memory as RAM, or did the ISA have I/O in,out opcodes for it with word address, or did it use the API for disk storage, or what?
  - mechagodzilla 7y ago
    Even the Cray-1S supported it! I believe it was connected via a 128-bit wide bus operating at the system clock speed (80 MHz in the case of the Cray-1), which made it a ~10 gbit interface. From a low-level software perspective, it was connected to a pair of DMA "channels" (1 input / 1 output), and there were instructions to do bulk copies from SRAM->CHANNEL or CHANNEL->SRAM. It may have used another slower channel pair as a command interface, but I'm not sure (nor how COS or UNICOS exposed it from a higher level software perspective).
jcoffland 7y ago
Some really early computers stored bits in waves in mercury. A series of waves would be started at one end of a tube full of mercury and they would be read back when they arrived at the other end. The memory of course then had to be refreshed. Core memory was however much more successful. https://en.m.wikipedia.org/wiki/Delay_line_memory https://en.m.wikipedia.org/wiki/Delay_line_memory
- agumonkey 7y ago
  Same idea was used between satellite and ground, wave was used as a memory that could be reused when back to station.
  - winrid 7y ago
    Holy crap that's so cool. Thanks for that info.
    - agumonkey 7y ago
      Some teacher that worked for the french ministry in the 80s told us that. It makes sense but I never found data on it. I'm not 100% sure it was done because he was a bit of a big mouth but at the same time he was in the field for decades so..
      - winrid 7y ago
        ah yeah I haven't found anything. Still a cool idea, however I'd imagine you'd have issues with data loss.
- Avery3R 7y ago
  An example of delay line memory using a wire that vibrates: https://www.youtube.com/watch?v=2BIx2x-Q2fE https://www.youtube.com/watch?v=2BIx2x-Q2fE
sliken 7y ago
Register latency is usually around 4ns (2.5-3.5 Ghz with a pipeline depth of 12-16). The article claims main memory latency is 7x more, which is around 24ns to 45ns. I tried to come up with plausible numbers that fix the 7x ratio they mention. These days main memory latencies are more around 70-80ns (single sockets) and 80-100 ns (dual sockets). Being off by so much does make me wonder about the accuracy of the rest of the article.
sliken 7y ago
My dad had a 256bit memory module on his desk. Made out of sandwich of two pieces of glass and 16 vertical and 12 horizontal wires. Each intersection had a small ferrous ring. Around that time he was programming and early computer and you could actually hear the memory bits changing. He was excited listening to it, figuring each click was a loop. Then her heard a different sound and realized he as hearing instructions and not loops.
ntw1103 7y ago
I recently upgraded my laptop to a Thinkpad T470s, which supports M.2 NVMe, and M.2 Sata. I upgraded from a 500gb NVMe drive to a 1TB M.2 sata drive. Why do I say upgraded if it is slower? Well, in a laptop, power usage is hugely important, as is heat. To prevent throttling on the CPU, less heat is better. I did a lot of research, and found that the sata based M.2 drives consume less power, and generate less heat. For my purposes the sata speed is sufficient. :)

92 points by workrockin 7y ago

3xblah 7y ago

Will the expression "spin up" ever fall out of usage?

NikolaeVarius 7y ago
Doubt it, though I don't think that I've used it in the context of SDD's recently since latency is that low. I think colloquially, it's pretty much understood to mean "time between turning on and being useful"
modzu 7y ago
language is symbolic so there doesn't have to be a literal connection between the reference and referent. for example you still "boot" a computer, which comes from the concept of "bootstrapping", ie, pulling oneself up by the straps of their boots. no boots are involved.
bluedino 7y ago
We 'spin up' virtual machines or instances now
- NullPrefix 7y ago
  Because once you hit the launch button your mouse cursors starts spinning.
jyrkesh 7y ago
Contrary to what others said, it will likely fall out of favor the way the floppy icon faded for "Save" functionality in GUIs. It's everywhere until one day you realize you can't find it in any of the apps you use every day.
- SketchySeaBeast 7y ago
  Doing a quick survey of the apps on my machine, it seems like most have just forgone the button altogether. For those that still have the button, the floppy icon seems to still be there.
  - Cthulhu_ 7y ago
    Yeah, purely from memory here but it's not that the save icon went out of fashion, but the concept of an icon bar or ribbon has gone; Microsoft's current UI standard for their native apps still has a ribbon IIRC, but I feel like that's one of the last vestiges. Using real world analogies went out the window after skeuomorphic design was no longer a thing too. Oddly enough, for me I had trouble adjusting to the 'folder' icon (or referring to folders as folders), we grew up with the term "directory" and I never had an association with anything physical with that.
- vbezhenar 7y ago
  Latest Word: it's there; paint brush: check; paint.net: check; editpad: floppy. Even Intellij Idea uses floppy. Actually from a quick glance I did not find a single application which did not use floppy icon as a save pictogram. May be it's Mac world? Apple is eager to forget old ways.
tyingq 7y ago
It was in wide use for jet and turbine engines, centrifuges, gyroscopes, etc, before disk drives. I don't think it will fade away.
niccl 7y ago
At least one of the D's in the acronym usually means Disk, and there isn't a disk in many of these. Will that ever go, do you think?

spectramax 7y ago

I am surprised the article doesn't talk about Optane technology: https://en.wikipedia.org/wiki/3D_XPoint https://en.wikipedia.org/wiki/3D_XPoint

Nursie 7y ago
Is Optane really 'all that' compared to other PCIe storage? I know that Intel are positioning it as some sort of system accelerator, and I know it does tend to score well in comparisons... but not "This is in a completely different category" well, AFAICT. What's special about it compared to, for instance, Samsung's NVMe offerings?
- sithadmin 7y ago
  Optane tends to crush the competition in terms of latency and random I/O, and mixed workload benchmarking. Samsung Z-NAND performs just slightly better on sequential I/O.
- synack 7y ago
  Optane is persistent and bit-addressable, with mean latency under 1 microsecond, which is an order of magnitude faster than other SSDs. I don't think the market has figured out the right use case for Optane yet. The majority of desktop applications won't benefit from lower latency IOPS and it's too expensive to use for general purpose storage on servers. It does make sense for constant write or seek-heavy applications like database journals, but most databases are optimized for doing bulk sequential reads/writes and won't take advantage of Optane's bit addressable storage. Intel's recently started shipping Optane DIMM modules that act like slow, cheap, high density RAM. This is an interesting option as it allows in-memory databases to be atomically persistent without having to add any code.
  - wtallis 7y ago
    > This is an interesting option as it allows in-memory databases to be atomically persistent without having to add any code. It isn't quite that simple. To start with, you need either a cache line flush or cache line writeback instruction to get you data out to persistent storage. And the Optane DIMMs currently are used in one of two modes: as transparent expansion of DRAM or as separately addressed and managed storage. In the DRAM-like mode, the system's actual DRAM is used as a cache, and the Optane storage does not persist across reboots. In the storage mode, you need extra code to access it, though you can treat it as simply a block device instead of using special-purpose persistent memory programming interfaces.

edoo 7y ago

I use LVM and have enough storage that all SSD would be a little expensive so for the last few years I've been using the block caching LVM feature with mirrored NVME drives as a writeback cache to my large HDD array. It greatly increases the performance of the storage with little hassle. If haven't played with gluster for a few years but it has a tiered storage feature so the most recently used files actually get moved onto the high speed storage medium, which depending on your workloads might be even better, assuming gluster is now performent and stable enough.

brianpaul 7y ago

FWIW, I believe Cray had an SSD option for the X-MP back in the early 80s.

theideaofcoffee 7y ago
They sure did! It came in 256-, 512- and 1024-MB flavors, if i recall, in its own cabinet off to the side at a blazing 1000MB/s. I don’t have a hunk of the SSD, but I have a (30lb) board of the central memory perched against my desk right now.
wolf550e 7y ago
From the brochure, it had a few million of 64-bit words worth of RAM that was used as regular RAM ("central memory") and a lot more of ECC DRAM that was used as fast storage ("SSD"). What was the API for the SSD? Was it mapped into virtual memory as RAM, or did the ISA have I/O in,out opcodes for it with word address, or did it use the API for disk storage, or what?
- mechagodzilla 7y ago
  Even the Cray-1S supported it! I believe it was connected via a 128-bit wide bus operating at the system clock speed (80 MHz in the case of the Cray-1), which made it a ~10 gbit interface. From a low-level software perspective, it was connected to a pair of DMA "channels" (1 input / 1 output), and there were instructions to do bulk copies from SRAM->CHANNEL or CHANNEL->SRAM. It may have used another slower channel pair as a command interface, but I'm not sure (nor how COS or UNICOS exposed it from a higher level software perspective).

jcoffland 7y ago

Some really early computers stored bits in waves in mercury. A series of waves would be started at one end of a tube full of mercury and they would be read back when they arrived at the other end. The memory of course then had to be refreshed. Core memory was however much more successful. https://en.m.wikipedia.org/wiki/Delay_line_memory https://en.m.wikipedia.org/wiki/Delay_line_memory

agumonkey 7y ago
Same idea was used between satellite and ground, wave was used as a memory that could be reused when back to station.
- winrid 7y ago
  Holy crap that's so cool. Thanks for that info.
  - agumonkey 7y ago
    Some teacher that worked for the french ministry in the 80s told us that. It makes sense but I never found data on it. I'm not 100% sure it was done because he was a bit of a big mouth but at the same time he was in the field for decades so..
    - winrid 7y ago
      ah yeah I haven't found anything. Still a cool idea, however I'd imagine you'd have issues with data loss.
Avery3R 7y ago
An example of delay line memory using a wire that vibrates: https://www.youtube.com/watch?v=2BIx2x-Q2fE https://www.youtube.com/watch?v=2BIx2x-Q2fE

sliken 7y ago

Register latency is usually around 4ns (2.5-3.5 Ghz with a pipeline depth of 12-16). The article claims main memory latency is 7x more, which is around 24ns to 45ns. I tried to come up with plausible numbers that fix the 7x ratio they mention. These days main memory latencies are more around 70-80ns (single sockets) and 80-100 ns (dual sockets). Being off by so much does make me wonder about the accuracy of the rest of the article.

sliken 7y ago

My dad had a 256bit memory module on his desk. Made out of sandwich of two pieces of glass and 16 vertical and 12 horizontal wires. Each intersection had a small ferrous ring. Around that time he was programming and early computer and you could actually hear the memory bits changing. He was excited listening to it, figuring each click was a loop. Then her heard a different sound and realized he as hearing instructions and not loops.

ntw1103 7y ago

I recently upgraded my laptop to a Thinkpad T470s, which supports M.2 NVMe, and M.2 Sata. I upgraded from a 500gb NVMe drive to a 1TB M.2 sata drive. Why do I say upgraded if it is slower? Well, in a laptop, power usage is hugely important, as is heat. To prevent throttling on the CPU, less heat is better. I did a lot of research, and found that the sata based M.2 drives consume less power, and generate less heat. For my purposes the sata speed is sufficient. :)