Does rebooting your pc clear your ram?

Does rebooting your pc clear your ram?

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Since the reboot doesn't cut power, technically not.

However, everything is being initialized a new and the OS does not give out memory pages before clearing it. So practically there is no way of recovering any of that information without having kernel level access.

Doesn't a reboot go through the whole power cycling and BIOS again, specifically to ensure that the state will be identical to what it would be after a cold boot?

Whether it power cycles or not depends on the Motherboard. In my case (laptops, Desktops) it doesn't power cycle.
You can't magically set RAM to clear. You have to zero out the cells. That takes a long time. So unless power to RAM is cut, nothing will clear it.

Modern kernels pre-zero parts of ram and keep it as a "hot spare" to give to programs who request it to save on latency. There is a great talk on this, though I can't remember where. (I believe it was analyzing why GNU's yes is so fast)

The info I can find says refresh time for a cell in the DDR standard is 64 ms max, so I would expect a sub-second power cycle to completely clear the data.

64ms max?
Holy shit that's horrible. Today's clear times are measured in nano seconds.
A RAM cell holds a single bit.
8gb of RAM = 8,589,934,592 byte = 68,719,476,736 bits stored in cells.

You can only access one RAM channel at ones. You can queue commands, but cannot make them execute parallel. So in single channel mode this would be a worst cause scenario of 140 years.

You can clear RAM by the speed of it's write bandwidth. Intel lists 68gbit/s as the theoretical max for DDR4 with all channels exhausted and the max rated ram speed.
So in the best cause scenario (quad channel included) it would take a second to clear 8gb ram.
In reality we have bigger capacities, not quad channel and slower rated speeds, so expect 16gb of ram to clear in 5 - 10 seconds.

The specs have a lot of additional info on how a full cell clear has to be spluit up in over 8k smaller clears, which are then split up even further.
I doubt they were talking about individual bits, "cells" are probably much larger units and defined somewhere else in the spec.

No. Absolutely no. It's a clearly defined as something that can only hold a single bit.

Doesn't matter if the spec allows you to pack multiple things. The clear has to be written and that happens at the max possible write speed.

It's lower in practice. Refresh period is defined by tREF/tREFI timing which stands for DRAM refresh interval. For DDR3-1333, JEDEC standard sets it to 5200, and that is about 7.8ms. Higher frequency standards increase tREF accordingly to maintain 7.8. Some DIMM modules will tolerate the period being bumped to 20ms, but it depends in ICs, temperature, and voltage. I have some Samsung HCH9 based DDR3 sticks that don't like going beyond 16ms. If the refresh period is too large, the charge in the cells will deteriorate, and data corrupts. I doubt the CPU IMC/MoBo MC keeps constantly refreshing memory without skipping a single beat even during the reboot cycle, so while it won't be clean as in zeroed out, the data also won't be pristine.

Some server/workstation firmware will clear on boot if memtest is enabled.

Most of the time, yes.

Fast startup or fastboot just dumps the startup stuff loaded on the RAM into your disk and during boot up it just dumps back what's on the disk into your RAM so rebooting on windows won't do.
But most of the time it is up for your mobo to decide not to mention if that mobo is glow.

That refresh time specification is about how frequently it needs to be refreshed in order to reliably maintain full data integrity. It is not any sort of guarantee that all the data will be gone, which is likely to take much longer

How much longer though? If I remember right, a cell is considered charged (logical one) if the voltage of the charge in it is higher than Vref, and if the voltage dips below Vref, the cell counts as discharged (a zero respectively). Vref normally is half of VDDQ, so refresh interval can be described as denoting the time it would take for at least one cell to lose half the voltage of its charge under normal conditions. The standard obviously has a very safe time estimate of that, but the need to be constantly refreshed limits throughput of DRAM, so I doubt the actual refresh limit is, say, an order of magnitude bigger. Once the voltage in all cells drops below Vref, the module is effectively clean.

It's temperature dependent, but potentially long enough to recover stuff, as these researchers demonstrated.

No it doesn't. Face it, you're going to get caught, you sick fucking scumbag. I pay my taxes every year with a smile, knowing part of it goes to keeping deviants like you locked away from the rest of us.

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>The observation that the computer’s volatile memory can maintain content for certain seconds even minutes after shut down of power supply, was recently confirmed by a team of researchers from the University of Princeton (Halderman et al., 2008).
So unless a full memory flush is performed at shutdown, the data retention after warm boot (and possibly even after cold boot following a short power off duration) is good enough for bioluminescent melanin hoarders to bother extracting. Answers OP's question.

why not clear memory the same way you would clear a hard drive
make a ramfs
dd if=/dev/zero bs=4096 of={ramfs}

I don't know what happens when it maxes out your ram, probably starts swapping
if you have a swap maybe only write enough data to ramfs to max memory and a tiny bit of swap so the system doesn't totally crash.
If I remember correctly shutting down and waiting 15 minutes should be enough.

This will not clear memory of open applications/the operating system.

of course this wouldn't clear any open applications, they are open and running.

this could be hooked into the shutdown sequence somewhere. most of the shit that people care to be wiped would be applications in userland, once that's all closed during a shutdown this could be run to clear memory

The Tails project have done work on this. The residual operating system complicates the task greatly, so the most effective approach is to have the final shutdown action of the OS be to kexec into a new single-purpose "kernel", dedicated to the function of wiping RAM then shutting down or rebooting. They tried modifying memtest86+ for this purpose, and it was pretty effective. I'm not sure where they are with it now:

You must be new here.

The first point that you need to note is that Whites were historically a great civilization. I don't deny that, after all, they controlled over 3/4 of the world at some point.
The second point that you need to note is that Asians are autistic bug-people with no empathy. No empathy = less societal progress since they let people die randomly despite their worth to society.
The third point that you need to acknowledge is that white people have lost any and all traits which made them a powerful and superior race. You NEET-Sock larpers take achievements from the last great men in NS Germany and attempt to make them your own. You haven't done shit. White people are 100% jew controlled, and this isn't because the jew is particularly powerful. This is because white people are emotionally weak. Why? Whites have been undergoing severe devolution over the past 100 years. The two jew-induced world wars killed off entire generations of strong, brave white men, and this has KILLED THE WHITE RACE. You pathetic Nig-Sock larpers need to understand this. There's no coming back from this.
White people are weak and pathetic. They have lost 100% of what made them great through a jewish dysgenics program, and while this is unfortunate, it is also irreversible. So forget about it.
Hapas, more specifically White/Asian hapas, are the new ubermensch, so to speak. We are superior to both whites and asians since the properties of both races are polar opposites, yet meet in the middle to form an optimal combination. Whites are too cucked and have too much empathy, so much so that they feel excessive empathy to subhuman races like niggers, jews and arabs.
On the opposite side of the scale, asians have too little empathy, being perfectly content to watch their fellow countrymen run over by trucks, poisoned by fake food products, gassed by the very air in their cities, and executed by their own government for petty reasons.
These two qualities are, as I mentioned, polar opposites, and neither are beneficial to the well-being of society. Hapas possess something in the middle of these polar opposites. We are much more racist than white people. And at the same time, we have empathy towards each other. Our women are far less slutty than white roasties, contrary to /poo/ disinformation - white men prefer white or asian women, not hapas. I know this not only due to theoretical knowledge but due to actual life experience talking to others of my own kind. We only require the tiniest push to fully support anti-nigger, anti-shitskin and anti-kike ideology, whereas whites never go all the way. Whites can only become magakikes, or anti-illegal-immigrants at the ABSOLUTE best.
Hapas are small in number at the moment but with further degeneration of the white race, racemixing between whites and asians will become more frequent. Hapas will rise from the ashes of the white race and inherit the world.
It is often stated by Nig-Socks that racemixing is evil and bad because "the product of racemixing contains neither of the desirable qualities of the two parent races". This may be true under ideal conditions, but Whites and Asians don't have any desirable qualities by themselves. The races have been degenerated by decades of communist (i.e. jewish) dysgenics (in the case of asians) or decades of war-induced jewish dysgenics (in the case of whites). As such, the ordinary Zig Forums theory no longer applies. Neither of the parent races, whites or asians, actually are suited to their environment. They also happen to have polar opposite qualities, which conflict with the goal of societal stability. This is why hapas are not inferior, but superior to both races.
Note that what I said only applies to White/Asian hapas. Any mixtures containing shitskin or nigger genetics is just as bad as the shitskin or nigger genetics would be by themselves, since shitskins and niggers were never a part of great civilization.