4 ms·

There's probably not much of anything that would survive that many power cycles in a day. The test is pretty pointless.

by AmVess 13y ago

ak217 13y ago
It's not pointless, just misrepresented. SSDs enable new classes of applications for high-performance, non-power-protected computers. With an SSD and Intel ULV CPU, I can put together a cheap high-performance computer with no moving parts and no batteries. That has the potential to be very robust and have an expected lifetime of decades, but only if the SSD is rock solid.
- cwzwarich 13y ago
  Which SSD is going to last for decades in a strenuous environment?
  - ak217 13y ago
    Intel, apparently
    - RyanZAG 13y ago
      This test really doesn't prove that at all. There are vastly different factors between power cycling in a single day and long term continuous use. You can't take results from one and get any meaningful information about the other.
      - ak217 13y ago
        You're right. But it does show one way in which it's resilient. Given this information and what else I know about Intel SSDs, I would expect them to be the most resilient overall.
rlpb 13y ago
What if I have thousands of disks deployed, and I suffer a single power loss? What are the chances that at least one disk will contain corrupt data after such an event? Instead of buying thousands of disks to test this scenario, one reasonable shortcut might be to repeatedly test a single disk. Even a spinning disk can handle a few thousand power cycles in its lifetime, surely?
- AmVess 13y ago
  On power up, there's a pretty big spike in power usage as the controller gets its shit together. Normally, this is not an issue, since the SSD housing simply absorbs the heat and then goes about its business. The same holds true for spindle drives. What this guy did was test the drives in a manner they weren't designed for. Sure, I can drop Corvettes off a 20 story building, then bitch about the results, but that wouldn't change the fact that my test was flawed from the onset. All he did was subject something to an environment is wasn't designed for. Sure, I can drop a Corvette from a 20 story building, but there's nothing to be gained when the crumple zone is packed into the tail lights.
  - zAy0LfpBZLC8mAC 13y ago
    Hu? Where should that spike in power usage come from?
    - rational_indian 13y ago
      It comes from the decoupling/filter capacitors used in the DC power circuit. When the power is turned on after a sufficiently long time these capacitors are all uncharged and appear as "shorts" to the power source thus drawing large amounts of current. This initial surge current drops off as the capacitors get charged.
      - zAy0LfpBZLC8mAC 13y ago
        Filter capacitors producing excessive heat due to inrush current? That would be bad filter capacitors indeed ;-) The claim was that an SSD somehow converted more electric energy into heat immediately after power-up which would damage the SSD, so real consumption, not just a current peak that goes into storage for later consumption. Normal-ESR electrolytics might have a heat problem when used at a few kHz in switching applications, but certainly not at 0.1 Hz.
ytjohn 13y ago
From what they said about these reading sensor data, I'm picturing a factory, industrial, or field type scenario. I'm picturing a very small embedded computer with some sensors attached and an internal ssd. Referencing a 1.5gb OS like they did makes me think they just have a normal OS installed, but it's entirely possible that they have a modified kernel and fast boot process. Essentially, it sounds like they have a single unit that gets turned on, gathers sensor readings, and then get turned off. I'm guessing these are not handheld devices, otherwise they most likely would have a battery attached. If a non 24/7 factory, these could be turned off with the rest of the assembly line by someone throwing breakers off on the way out (very common).

There's probably not much of anything that would survive that many power cycles in a day. The test is pretty pointless.

by AmVess 13y ago

There's probably not much of anything that would survive that many power cycles in a day. The test is pretty pointless.

ak217 13y ago

It's not pointless, just misrepresented. SSDs enable new classes of applications for high-performance, non-power-protected computers. With an SSD and Intel ULV CPU, I can put together a cheap high-performance computer with no moving parts and no batteries. That has the potential to be very robust and have an expected lifetime of decades, but only if the SSD is rock solid.

cwzwarich 13y ago
Which SSD is going to last for decades in a strenuous environment?
- ak217 13y ago
  Intel, apparently
  - RyanZAG 13y ago
    This test really doesn't prove that at all. There are vastly different factors between power cycling in a single day and long term continuous use. You can't take results from one and get any meaningful information about the other.
    - ak217 13y ago
      You're right. But it does show one way in which it's resilient. Given this information and what else I know about Intel SSDs, I would expect them to be the most resilient overall.

rlpb 13y ago

What if I have thousands of disks deployed, and I suffer a single power loss? What are the chances that at least one disk will contain corrupt data after such an event? Instead of buying thousands of disks to test this scenario, one reasonable shortcut might be to repeatedly test a single disk. Even a spinning disk can handle a few thousand power cycles in its lifetime, surely?

AmVess 13y ago
On power up, there's a pretty big spike in power usage as the controller gets its shit together. Normally, this is not an issue, since the SSD housing simply absorbs the heat and then goes about its business. The same holds true for spindle drives. What this guy did was test the drives in a manner they weren't designed for. Sure, I can drop Corvettes off a 20 story building, then bitch about the results, but that wouldn't change the fact that my test was flawed from the onset. All he did was subject something to an environment is wasn't designed for. Sure, I can drop a Corvette from a 20 story building, but there's nothing to be gained when the crumple zone is packed into the tail lights.
- zAy0LfpBZLC8mAC 13y ago
  Hu? Where should that spike in power usage come from?
  - rational_indian 13y ago
    It comes from the decoupling/filter capacitors used in the DC power circuit. When the power is turned on after a sufficiently long time these capacitors are all uncharged and appear as "shorts" to the power source thus drawing large amounts of current. This initial surge current drops off as the capacitors get charged.
    - zAy0LfpBZLC8mAC 13y ago
      Filter capacitors producing excessive heat due to inrush current? That would be bad filter capacitors indeed ;-) The claim was that an SSD somehow converted more electric energy into heat immediately after power-up which would damage the SSD, so real consumption, not just a current peak that goes into storage for later consumption. Normal-ESR electrolytics might have a heat problem when used at a few kHz in switching applications, but certainly not at 0.1 Hz.

ytjohn 13y ago

From what they said about these reading sensor data, I'm picturing a factory, industrial, or field type scenario. I'm picturing a very small embedded computer with some sensors attached and an internal ssd. Referencing a 1.5gb OS like they did makes me think they just have a normal OS installed, but it's entirely possible that they have a modified kernel and fast boot process. Essentially, it sounds like they have a single unit that gets turned on, gathers sensor readings, and then get turned off. I'm guessing these are not handheld devices, otherwise they most likely would have a battery attached. If a non 24/7 factory, these could be turned off with the rest of the assembly line by someone throwing breakers off on the way out (very common).