I’ve heard they received some kind of government healthcare grant early on, which requires them to keep providing services under the TikTok name for at least 15 years.
What does uncorrectable error mean in RAM? I’ve read somewhere that they use Hamming codes for ECC RAM. Isn’t it the case that too many errors (more than floor((d - 1) / 2)) simply result in an incorrect codeword? Or do they know the error locations a priori? (i.e. erasure coding)
First, let's define a correctable error — that means an error where you have enough additional information (in your Hamming-code stream, in a parity bit, whatever) to repair the error, e.g. a one-bit error when you're using ECC RAM.
An uncorrectable error, then, is one where you do have enough information to detect the corruption, but not enough information to figure out the correct repair for the corruption. (The amount of information required to detect corruption is always less than the amount of information required to correct it.)
With ECC RAM, usually exactly two bit-flips will produce a detected, but uncorrectable, error on read-back.
With non-ECC but "with a parity-bit per word" RAM (which exists, and is a bit cheaper than ECC RAM), you can't correct anything, only detect. (Which is sometimes all you need, if you're willing to do the calculation over again.)
All that being said: completely separately from these hardware-level features, some operating systems (e.g. macOS) compress memory, and generate page-level checksums of memory pages as they're compressed. A checksum failure during memory-page decompression can also trigger the kernel to throw this kind of "uncorrectable error" itself.
There may also exist (i.e. it wouldn't be impossible for there to be) RAM modules that continuously calculate page checksums for each page on each write; and then check the contents of pages against these, perhaps asynchronously, in sort of the same way a ZFS scrub works. I've never heard of this being done, but it feels like the sort of thing you'd implement in hardware for an extremely "ruggedized" system like a Mars rover. If this approach were to be implemented, it would also emit "uncorrectable" errors.
> With ECC RAM, usually exactly two bit-flips will produce a detected, but uncorrectable, error on read-back.
>> HPE Fast Fault Tolerant (ADDDC)—Enables the system to correct memory errors and continue to operate in cases of multiple DRAM device failures on a DIMM. Provides protection against uncorrectable memory errors beyond what is available with Advanced ECC.
Your intuition is right. Hamming codes work by packing that bit-space full of spheres and assuming the middle of each sphere is the codeword. Then error detection/correction is just mapping to the middle and detecting if that's different than what you started with. Since the space is completely filled, too many errors simply result in an incorrect codeword.
However, you can cheaply extend Hamming codes with, e.g., a parity bit, so that errors in a slightly larger radius are detectable, though for obvious reasons you couldn't correct such an error.
No comment on what sort of algorithm is used for ECC, though it might be worth mentioning that the above is a pretty general feature of error correction, where it's possible to cheaply or even for free be able to detect errors in a larger radius than you're able to correct.
Why does debouncing increase latency? Can’t they report the keypress immediately on the first signal spike, and then use the debounce timer to ensure that no additional presses are reported within the debounce interval?
Or are switches generating spurious signal spikes even when left untouched? That would explain why they need to delay the keypress…
I've been typing for a long time, and I think I type pretty quickly. I've never felt that my keyboard is slower than my typing. At least not since ZX-81 days.
What an interesting person. I don't agree with about half of it but I respect the courage to act on those beliefs. Looks like the software is in public domain, for example.
I can agree with you. I also disagree with much of what they wrote (although I did not count how much), but I believe that anyone should have freedom of speech whether it is agree or not.
But, most of that is not important for the software, since the computer programs can be judged by their own merits instead of everything else that the author does (especially if they are public domain).
Exactly what I thought. Some of what he believes in is maybe a bit excessive, but then again, maybe it's just outside of what we currently believe to be normal.
I respect the guy for speaking up (doxxing himself in the process too!)
Even if neural networks were fundamentally incompatible with conventional computation, I don't see why you couldn't augment a neural network with a conventional ALU to do the numerical computations. This is exactly what humans do with pencil and paper - it's just a bit too slow.
Either the language model would need to know what it's doing or the host program would have to know what the AI is doing. Both seem out of reach. The latter seems more doable since you could hack something up for simple scenarios, but you'd effectively have to match the capabilities of the neural network in a classical way to handle every case (which would render using a neural net moot).
Why do you want to know? I can't imagine how knowing that answer is going to make anything better for anyone here. Are you a mod of a similar service and need something to negotiate with? Even as a negotiating datapoint, it's only valuable if YC would hire you to moderate (which I doubt) and you can use that as leverage.
If it was public, then random users might demand more of dang, thinking that his salary justifies it.
Keeping salaries public in an industry lets you use them as a negotiating datapoint anywhere in that industry.
Not too related to the discussion, but I'm really hoping Twitch moderators start asking for a paycheck once their streamer's realtime chat reaches a certain size, as they have to stay quick and attentive for hours straight. But sadly, they often start when the streamer is smaller and work for them on their own dime and remain that way.
It's definitely none of your business, but as someone who does similar work, I'd guess in the territory of $100k–150k. (That's not how much I get paid, but I work at a much smaller and less established org.)
