5 ms·

Yeah, but then you have a write amplification problem. Padding is write amplification from the start, and then GC is invoked many more times than it otherwise w

by kmxdm 3y ago

Yeah, but then you have a write amplification problem. Padding is write amplification from the start, and then GC is invoked many more times than it otherwise would be. There is a fundamental problem with (truly) flushing an IO that is smaller than the media write unit. It will cause problems if "abused." The SSD either needs to take on the cost of mitigation (e.g. caps) or it needs some way to provide hints to the host that don't exist today.

nijave 3y ago
I'm curious what the real cost of power protection is for the manufacturer. Adding caps or a bit of backup power seems like it _should_ be a fairly cheap compromise to maintain performance without lying about persistence
- kmxdm 3y ago
  M.2/2280 makes it hard. Can't use cheaper aluminum can capacitors due to their size/height. The low profile (tantalum?) capacitors are expensive and take up a lot of PCB area, forcing a two sided PCB design on 2280 (the 110mm version would be better here). M.2 only provides 5V. On other form factors you get 12V and can get more charge stored for the same capacitance (q=CV) without needing a DC-DC converter.
- justsomehnguy 3y ago
  define 'cheap'? You already have the device shipped to you under $40 with packaging, shipping from China, to the distributor, to you; with a profit at the every step.
  - nijave 3y ago
    $1-5 I'd gladly pay a few bucks extra for a drive that doesn't delete my data when the power fails
    - justsomehnguy 3y ago
      > $1-5 For a $20 device this is 5-25% of the cost the product, assuming $40 retail cost. It would be 1-5% for a $100 product, of course. You would pay for a such device, but 99% of people wouldn't. Now you have a product which costs 5-25% higher than all your competitors and in the world where the price dictates the sales you have no opportunity to sell your product. NB to be sure on the prices I've checked Amazon. There are SSDs what are cheaper than many mounting trays, enclosures (without drives) and tray kits.
      - nijave 3y ago
        I'm not so sure price is the only competing factor for SSDs. Devices generally also differentiate on performance as well. Even on consumer-oriented Slickdeals forum (where people are posting deals) there's pretty extensive breakdowns comparing different SSDs (controllers, flash, cache design). This has been floating around for a while https://www.reddit.com/r/NewMaxx/comments/dhvrdm/ssd_guides_resources/ https://www.reddit.com/r/NewMaxx/comments/dhvrdm/ssd_guides_... Whether consumers would actually pay more for a device with power protection is unclear.
        justsomehnguy 3y ago
        Oof. Im in the bar RN, if you interested - leave a note, I would try to explain what I meant

by kmxdm 3y ago

nijave 3y ago

I'm curious what the real cost of power protection is for the manufacturer. Adding caps or a bit of backup power seems like it _should_ be a fairly cheap compromise to maintain performance without lying about persistence

kmxdm 3y ago
M.2/2280 makes it hard. Can't use cheaper aluminum can capacitors due to their size/height. The low profile (tantalum?) capacitors are expensive and take up a lot of PCB area, forcing a two sided PCB design on 2280 (the 110mm version would be better here). M.2 only provides 5V. On other form factors you get 12V and can get more charge stored for the same capacitance (q=CV) without needing a DC-DC converter.
justsomehnguy 3y ago
define 'cheap'? You already have the device shipped to you under $40 with packaging, shipping from China, to the distributor, to you; with a profit at the every step.
- nijave 3y ago
  $1-5 I'd gladly pay a few bucks extra for a drive that doesn't delete my data when the power fails
  - justsomehnguy 3y ago
    > $1-5 For a $20 device this is 5-25% of the cost the product, assuming $40 retail cost. It would be 1-5% for a $100 product, of course. You would pay for a such device, but 99% of people wouldn't. Now you have a product which costs 5-25% higher than all your competitors and in the world where the price dictates the sales you have no opportunity to sell your product. NB to be sure on the prices I've checked Amazon. There are SSDs what are cheaper than many mounting trays, enclosures (without drives) and tray kits.
    - nijave 3y ago
      I'm not so sure price is the only competing factor for SSDs. Devices generally also differentiate on performance as well. Even on consumer-oriented Slickdeals forum (where people are posting deals) there's pretty extensive breakdowns comparing different SSDs (controllers, flash, cache design). This has been floating around for a while https://www.reddit.com/r/NewMaxx/comments/dhvrdm/ssd_guides_resources/ https://www.reddit.com/r/NewMaxx/comments/dhvrdm/ssd_guides_... Whether consumers would actually pay more for a device with power protection is unclear.
      - justsomehnguy 3y ago
        Oof. Im in the bar RN, if you interested - leave a note, I would try to explain what I meant