| ▲ | Data Has Weight but Only on SSDs(cubiclenate.com) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 41 points by LorenDB 3 hours ago | 20 comments | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| ▲ | tliltocatl 3 hours ago | parent | next [-] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
I think the article is wrong in its core premise. While the electrons get added or removed from the floating gate, the total number of electrons in the SSD chip stays the same. Gates are capacitors, in order to add electrons to one capacitor plate, you have to remove an equal numbers of electrons from the other plate, i. e. from the transistor channel. The net charge of a SSD chip is always zero. Otherwise it would just go bang. <s>2.43×10^-15</s> [my bad 1] 2.67×10^15 electrons is about 300µC - that's a lot of charge to separate macroscopically. Therefore the mass (weight is a different thing, through it is proportional to mass at a given constant gravity potential) of the data on a SSD isn't fundamentally different from a HDD - they both are caused by a change of internal energy without any change in the number of fermions. I'd expect data on SSD to have larger mass change because a charged capacitor always store more energy than a discharged one, while energy of magnetic domains is less directional and depends mostly on the state of neighbor domains - but I'm not sure about this part. [1] Thanks stackghost. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
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| ▲ | TazeTSchnitzel 9 minutes ago | parent | prev | next [-] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Lights in video games are real, but only if you're using an OLED or CRT. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| ▲ | nwellnhof 2 hours ago | parent | prev | next [-] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Reminds me of an old April Fools' prank in German c't magazine. They offered a defragmentation-like tool for HDDs that claimed to distribute 0s and 1s more evenly on the drive to make it run more smoothly and extend its lifespan. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
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| ▲ | tlb 36 minutes ago | parent | prev | next [-] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
The rate at which molecules of plastic sublimate off the surface of the enclosure is probably a much larger amount of mass. The rate increases with e^kT, where k is such that it doubles about every 10 degrees C. So if you get a drive and fill it with data (which warms it up significantly) the lost casing material will dominate the mass balance. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| ▲ | stephbook 18 minutes ago | parent | prev | next [-] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Light bulbs in video games use real electricity. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| ▲ | alanh 14 minutes ago | parent | prev | next [-] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
"Data has weight, but only on SSDs" - Not just SSDs! Unless you always hang the chad, surely writing data onto punchcards reduces the weight of that 'storage medium'! | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| ▲ | epx 2 hours ago | parent | prev | next [-] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Was expecting Boltzmann and entropy to be involved at some point :( | |||||||||||||||||||||||||||||||||||||||||||||||||||||
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| ▲ | antimatter15 an hour ago | parent | prev | next [-] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Another fun calculation is that due to special relativity, a hard drive that is spinning gains a certain amount of mass due to the rotational kinetic energy and E=mc^2. Assuming the platter is 100g, 42mm, spinning at 7200RPM, there is about 25J of rotational kinetic energy, whose mass equivalent is 2.8x10^-13g (0.28 femtograms). Assuming 200 electrons per NAND floating gate with 3bits/cell TLC on a 2TB SSD, there would be 5.3x10^14 electrons, weighing about 0.5 femtograms. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| ▲ | themafia an hour ago | parent | prev | next [-] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
More appropriately data has a temperature. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| ▲ | jmclnx 2 hours ago | parent | prev [-] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
interesting, I wonder if one can translate this into the amount of data on the drive ? Maybe it does not matter unless one cleared the drive using dd(1). Also would trimming cause a different value even though the data size remains the same ? I would think so, assuming I understand trim. | |||||||||||||||||||||||||||||||||||||||||||||||||||||