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A typical CPU (or SSD even) uses a voltage of 0.9V currently, surely it doesn't matter whether the motherboard is converting 12V to 0.9V or 5V to 0.9V. Back wh

by jleahy 7y ago

A typical CPU (or SSD even) uses a voltage of 0.9V currently, surely it doesn't matter whether the motherboard is converting 12V to 0.9V or 5V to 0.9V. Back when this stuff was originally designed 12V, 5V and 3.3V was all you needed (actually with the AT standard it was just 12V for motors and 5V for logic, that was pre-CMOS). Now every component requires a different voltage (if there's any standard it might be 1.8V or 1.2V), and to get several hundreds watts of power at 0.9V would require cables about an inch thick. 12V is the defacto standard for powering pretty much anything these days. Converting 12V into whatever you want is utterly trivial and incredibly efficient.

michaelt 7y ago
Maybe for a lot of things, but I've seen plenty of SSDs that only need 5v power, and I've never seen one that only needed 12v.
- btian 7y ago
  You mean 3.3V (since M.2 is 3.3V only)? It's trivial to convert 12V to 3.3V tbh
  - michaelt 7y ago
    No, I mean if you look at 2.5" SSDs with datasheets specifying the operating voltages, they will commonly specify 5 volts. Intel SSD 530? "5.0V SATA Supply Rail" [1] Seagate 600 SSD? "+5V Max" [2] Toshiba SG5? "Supply Voltage 5.0 V ±5%" [3] Swissbit X-60? "5V± 10% (3.3 V available upon request)" [4] Apacer SV250-25? "5.0V ±10%" [5] So the statement that "12V is the defacto standard for powering pretty much anything these days" isn't accurate in the case of 2.5" SSDs. I acknowledge desktop computers often supply 12v to the motherboard and graphics card, of course! (Some 2.5 inch SSDs, like the Micron 5100 Series use both 5v and 12v [6] - and I agree that M.2 is 3.3v only) [1] https://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/ssd-530-sata-specification.pdf https://www.intel.com/content/dam/www/public/us/en/documents... [2] https://www.seagate.com/files/www-content/product-content/ssd-fam/600-ssd/en-us/docs/600-ssd-data-sheet-ds1780-3-1305us.pdf https://www.seagate.com/files/www-content/product-content/ss... [3] https://toshiba.semicon-storage.com/content/dam/toshiba-ss/asia-pacific/docs/product/storage/product-manual/SSD-SG5-Series-Brochure-Revision1.0.pdf https://toshiba.semicon-storage.com/content/dam/toshiba-ss/a... [4] https://www.mouser.co.uk/datasheet/2/615/X-60_fact_sheet-1633266.pdf https://www.mouser.co.uk/datasheet/2/615/X-60_fact_sheet-163... [5] https://www.mouser.co.uk/datasheet/2/24/SV250-25_AE2.255XXC.XXX04_Spec_rev1.1-1602155.pdf https://www.mouser.co.uk/datasheet/2/24/SV250-25_AE2.255XXC.... [6] http://www.mouser.com/datasheet/2/671/5100_ssd-1283974.pdf http://www.mouser.com/datasheet/2/671/5100_ssd-1283974.pdf
- wtallis 7y ago
  SSDs all have their own power management chips to manage their onboard voltage regulators. The flash memory itself is usually operating with 1.2V and/or 1.8V supply, and the SSD controllers are also in the neighborhood of 1V. Approximately nothing inside a modern PC uses 3.3V or 5V directly. Feeding 12V directly to the SSD won't make its power management circuits any more complicated or expensive, but it does get rid of the brown-out problem M.2 (3.3V) has with high-power drives.

by jleahy 7y ago

michaelt 7y ago

Maybe for a lot of things, but I've seen plenty of SSDs that only need 5v power, and I've never seen one that only needed 12v.

btian 7y ago
You mean 3.3V (since M.2 is 3.3V only)? It's trivial to convert 12V to 3.3V tbh
- michaelt 7y ago
  No, I mean if you look at 2.5" SSDs with datasheets specifying the operating voltages, they will commonly specify 5 volts. Intel SSD 530? "5.0V SATA Supply Rail" [1] Seagate 600 SSD? "+5V Max" [2] Toshiba SG5? "Supply Voltage 5.0 V ±5%" [3] Swissbit X-60? "5V± 10% (3.3 V available upon request)" [4] Apacer SV250-25? "5.0V ±10%" [5] So the statement that "12V is the defacto standard for powering pretty much anything these days" isn't accurate in the case of 2.5" SSDs. I acknowledge desktop computers often supply 12v to the motherboard and graphics card, of course! (Some 2.5 inch SSDs, like the Micron 5100 Series use both 5v and 12v [6] - and I agree that M.2 is 3.3v only) [1] https://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/ssd-530-sata-specification.pdf https://www.intel.com/content/dam/www/public/us/en/documents... [2] https://www.seagate.com/files/www-content/product-content/ssd-fam/600-ssd/en-us/docs/600-ssd-data-sheet-ds1780-3-1305us.pdf https://www.seagate.com/files/www-content/product-content/ss... [3] https://toshiba.semicon-storage.com/content/dam/toshiba-ss/asia-pacific/docs/product/storage/product-manual/SSD-SG5-Series-Brochure-Revision1.0.pdf https://toshiba.semicon-storage.com/content/dam/toshiba-ss/a... [4] https://www.mouser.co.uk/datasheet/2/615/X-60_fact_sheet-1633266.pdf https://www.mouser.co.uk/datasheet/2/615/X-60_fact_sheet-163... [5] https://www.mouser.co.uk/datasheet/2/24/SV250-25_AE2.255XXC.XXX04_Spec_rev1.1-1602155.pdf https://www.mouser.co.uk/datasheet/2/24/SV250-25_AE2.255XXC.... [6] http://www.mouser.com/datasheet/2/671/5100_ssd-1283974.pdf http://www.mouser.com/datasheet/2/671/5100_ssd-1283974.pdf
wtallis 7y ago
SSDs all have their own power management chips to manage their onboard voltage regulators. The flash memory itself is usually operating with 1.2V and/or 1.8V supply, and the SSD controllers are also in the neighborhood of 1V. Approximately nothing inside a modern PC uses 3.3V or 5V directly. Feeding 12V directly to the SSD won't make its power management circuits any more complicated or expensive, but it does get rid of the brown-out problem M.2 (3.3V) has with high-power drives.