Long story short, under a power outage SSD's need some time (fractions of a second) to write down some things, or else data corruption and even SSD bricking may occur.
Quality SSDs include a supercapacitor:
... or a troop of smaller caps:
... to auto grant themselves some miliseconds of grace.
But more pedestrian consumer SSDs lack any of these, and thus are vulnerable to power outages.
Now have a look at what this guy figured out
:
I've done a bit of testing with multimeter, and even a gutless wonder can keep the +5VSB alive for about seven seconds after switching off the PSU from the wall, plenty enough for the SSD to shut down safely in the event of a power outage
.
What do you guys think about the idea?
(And if possible please don't just tell me 'get an UPS!'
)
Quality SSDs include a supercapacitor:
... or a troop of smaller caps:
... to auto grant themselves some miliseconds of grace.
But more pedestrian consumer SSDs lack any of these, and thus are vulnerable to power outages.
Now have a look at what this guy figured out
:
"... was considering some means of delaying the loss of 5v power to the SSD over and above the general loss of usable power to the rest of the system during the power down sequence.
Possible solutions that I considered included using a low volt drop diode and a whacking great capacitor in the 5v line followed by an even better solution of using a diode with a whacking great capacitor in the 12v feed to a 5v switching converter to feed the SSD with 5v power.
In the end, I decided to try an even less exotic solution which was simply to transfer the 5v wire in the single SATA power connector feeding the SSD across to the 5vSB line ...
... the much more slowly decaying 5vSB line when I switch the mains supply off at the back of the PSU[4] a few seconds after the OS mediated shutdown has completed and take panic action to commit the data to the NVRAM with the much extended time interval before the 5vSB drops to the 4.75v lower critical limit (no drain on the HT caps from the main PSU rails should make the 5vSB rail decay a much more protracted process than that on the regular 5v rail).
The only downside with this modification is the extra power drain on the 5vSB line from the SSD. In my case, an extra 1.8W on top of the 3.8W the PC draws from the mains when it is in the shutdown state. Since, according to Intel's technical specs for this drive, it takes 600mW idle and 830mW active, the efficiency of the PSU in this mode looks to be just under 50%. Quite frankly, the extra 1.8W[4] is neither here nor there and is a price well worth paying if it solves the win2k powerdown SSD corruption issue.
... In my case, that extra 1.8W in standby due to using the 5vSB to power the SSD is effectively eliminated by my habit of switching the AC power off after each and every shutdown."
http://www.techiehq.net/diy-computer...ion-89269.html
Possible solutions that I considered included using a low volt drop diode and a whacking great capacitor in the 5v line followed by an even better solution of using a diode with a whacking great capacitor in the 12v feed to a 5v switching converter to feed the SSD with 5v power.
In the end, I decided to try an even less exotic solution which was simply to transfer the 5v wire in the single SATA power connector feeding the SSD across to the 5vSB line ...
... the much more slowly decaying 5vSB line when I switch the mains supply off at the back of the PSU[4] a few seconds after the OS mediated shutdown has completed and take panic action to commit the data to the NVRAM with the much extended time interval before the 5vSB drops to the 4.75v lower critical limit (no drain on the HT caps from the main PSU rails should make the 5vSB rail decay a much more protracted process than that on the regular 5v rail).
The only downside with this modification is the extra power drain on the 5vSB line from the SSD. In my case, an extra 1.8W on top of the 3.8W the PC draws from the mains when it is in the shutdown state. Since, according to Intel's technical specs for this drive, it takes 600mW idle and 830mW active, the efficiency of the PSU in this mode looks to be just under 50%. Quite frankly, the extra 1.8W[4] is neither here nor there and is a price well worth paying if it solves the win2k powerdown SSD corruption issue.
... In my case, that extra 1.8W in standby due to using the 5vSB to power the SSD is effectively eliminated by my habit of switching the AC power off after each and every shutdown."
http://www.techiehq.net/diy-computer...ion-89269.html
I've done a bit of testing with multimeter, and even a gutless wonder can keep the +5VSB alive for about seven seconds after switching off the PSU from the wall, plenty enough for the SSD to shut down safely in the event of a power outage
.What do you guys think about the idea?
(And if possible please don't just tell me 'get an UPS!'
)
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