Hi
Updoot if you get the reference
- Posts
- 3
- Comments
- 218
- Joined
- 3 yr. ago
- Posts
- 3
- Comments
- 218
- Joined
- 3 yr. ago
- JumpDeleted
Permanently Deleted
- JumpDeleted
Permanently Deleted
In addition to the other comment, a lot of companies typically sell support for their software, not the software itself. That counts for a lot in the business world
Sewing/designing clothes really clicked for me. Haven't tried woodworking, but I imagine it scratches the same itch and utilizes similar skills: 90% of sewing is just planning, calculation, and measuring. Then, watch everything just fit together into place
Good question. I had to modify my code to run more efficiently, since not throttling implies that the copper block reaches a steady state with very little temperature changes over time.
But, with the changes, I can say that there is no copper block length that would prevent throttling with a 120 W CPU. It seems the heat transfer within the block is slow enough over such long lengths that you get diminishing returns with longer and longer copper blocks. Here's a graph I made summarizing the different block lengths that I tested
With a 65 W CPU, a 32 cm (double the original length) copper block is sufficient to prevent throttling, but it'll reach steady state at 97 C
I left another comment going into more detail about the model specifications, if you'd like to read into it. But briefly: I took the copper heat conductivity coefficient and the air heat transfer coefficient. I sliced the copper block into thin slices and modeled heat transfer between each slice, as well as heat transfer between each slice and the surrounding air.
It seems that both heat transfer and heat loss do actually matter quite significantly, but they just cancel each other out almost entirely.
If we assume instantaneous heat transfer, thermal throttling time goes up from 592 seconds to 703 seconds (about 2 minute difference).
If we assume no heat loss to the air, thermal throttling time goes down from 592 seconds to 500 seconds (about 1.5 minute difference).
Copper conductivity is fast, sure, but it's not fast enough to have equal temperatures at the top and bottom for such a big chunk of copper. That does affect the time to thermal throttle pretty significantly, actually. If we assume completely homogeneous temperatures across the block (ie, instantaneous heat transfer), according to my model, it'll take 703 seconds to thermal throttle. With heat transfer, the time drops to 592 seconds - a difference of about 2 minutes
Was intrigued, so made a simulation to figure it out.
TLDR: 592.2 seconds, or 9 minutes and 52.2 seconds. Very similar to the other comment - it appears temperature differentials and heat loss to the air have opposite effects on thermal throttle time and mostly cancel themselves out. For the most part, heat transfer and heat loss appear to affect the thermal throttle time less than the sheer heat mass of the block by several multiples
Assumptions:
- Copper's heat conductivity is 400 W/m-K, and specific heat is 0.4 J/g-K, and density is 9000 kg/m^3, and these values do not change over the range of temperatures
- Air's heat transfer coefficient is 20 W/m^2-K and does not change over the range of temperatures
- The surrounding air does not change in temperature and remains at room temperature (25 C)
- The input wattage is actually 120 W and not just random marketing bullshit
- The copper block's size is 4 cm x 4 cm x 16 cm (same as other comment)
- The temperature within the copper block differs only by the vertical axis; it is assumed that temperature does not change if you move horizontally into the block
Modeling conditions:
- The block is sliced into 100 equally-sized slices, stacked vertically.
- Each slice starts off with a temperature of 25 C
- 120 W is input directly into the bottom slice
- Heat transfer is modeled between each slice
- Heat loss into the air is modeled for each slice (top slice has more heat loss due to more contact with the air)
- Temperature changes are calculated per millisecond
- Final time is calculated by the total number of milliseconds it takes for the bottom slice to reach a temperature greater than 100 C
Fun facts I found from playing around with the model:
- According to this model, at the time that the CPU thermal throttles, the top of the block should be 85 C
- If we assume instantaneous heat transfer, time to thermal throttle goes up to 703 seconds (11 minutes and 43 seconds). Difference is about 2 minutes.
- If we assume no heat loss to the air, time to thermal throttle goes down to 500.0 seconds (8 minutes and 20 seconds). Difference is about 1.5 minutes.
- The copper block should be able to prevent throttling as long as the CPU remains idle (30W for AMD CPU's). The CPU should cap out at around 82-83 C.
- The copper block can prevent thermal throttling for a 170 W CPU for 368.1 seconds, or 6 minutes and 8.1 seconds
- JumpDeleted
Permanently Deleted
You're confusing 2 different but related concepts. Blueshift and redshift does depends only on velocity. In the cosmological sense, redshift (the opposite of blueshift) occurs because everything is moving away from everything else due to the expansion of the universe, and so the distance of an object can be calculated based on how much redshift there is in the light. Basically, on a cosmological scale, distance and velocity are connected
Hmm, I think at minimum calculus will need to be involved here. Because we can't just assume that the heat is spread evenly in the copper - it'll likely be hotter at the bottom, leading to thermal throttling earlier than expected. On the other hand, there's going to be heat dissipation into the air, which will help cool the block somewhat
Edit: made a program to model heat transfer and heat loss. It seems to only affect final time by a handful of seconds. So actual time in real life is probably somewhere in the ballpark of 10 minutes
If I were to guess, probably heat stroke due to rising temperatures. Which, if true, would also be worsened by having more data centers
- JumpDeleted
Permanently Deleted
That's just how ERK looks like. It's 44 kDa and 42 kDa, which makes it so that you either see 2 bands, or, more likely, you get 1 big fuzzy band
- JumpDeleted
Permanently Deleted
I think, at the core, my argument is simply this: don't rush into sex. Take your time to figure out if this is really what you want.
I believe everyone can agree to that statement. But my perspective is that quantifiable, actionable advice is more helpful than advice in which the recipient has to apply their own judgment (what's the purpose of giving the advice then?), and so I have semi-arbitrarily chosen that 6 months to wait is a safe bet and 1 year is ideal.
And I acknowledge that waiting a year is unusually chaste - that's why I consider it to be an ideal circumstance rather than a practicable target. Is waiting a year for sex unusually risk-averse? Yes, undeniably. But you also can't deny that waiting that time would give you the best perspective on whether or not it's a good idea to have sex with someone
- JumpDeleted
Permanently Deleted
I think we're actually on the same page then. I don't think you're wrong in any way, I just also don't think these 2 perspectives are necessarily mutually exclusive
- JumpDeleted
Permanently Deleted
Very true, I acknowledge that safe sex can be had much earlier. But I don't think my advice is as absurd as it sounds at first glance.
6 months seems long on paper but from what I've observed, it's really not that long in context. By my estimate, that's around the time when a casual relationship transitions into a more serious relationship. So really, all I'm saying is to make sure that you're serious before you commit to taking the risk. I'm just drawing a semi-arbitrary line to delineate a casual and a serious relationship. I consider it to be more actionable to have a solid number, especially for someone who doesn't yet know what a casual or a serious relationship looks like.
In context, I know an acquaintance whom I would describe as very free-spirited. She ended up waiting something like 4 months before her first sexual contact with her significant other, and that was without any advice. So 6 months is quite doable in my opinion.
There's certainly nothing morally wrong with casual sex, I do not hold it against someone if they choose to have sex before 6 months. But practically speaking (and I would argue that an inexperienced person is in most need to hear practical advice), I still stand by my stance that it's a good idea to err on the side of caution. It's always more preferable to start having sex too late than to start having sex too early. And that's especially true when you factor in that we are starting off this potential relationship with some concerning red flags
- JumpDeleted
Permanently Deleted
I think sexual intimacy can be okay at an earlier stage, as long as you ensure clear and honest communication beforehand about expectations and comfort zones.
Completely fair point. It's definitely a lot more nuanced than I wrote.
In my eyes, I find that there's a lot of pressure to have sex, and very little pressure to hold off. This is especially true for inexperienced people. People will tend to rationalize themselves into having sex, even when in hindsight they really weren't ready. So to avoid having to consider edge cases and/or irrational thinking, I find that just setting a hard-and-fast rule where you just really should not have sex for x amount of time ends up being the simplest and most applicable advice
Science Memes @mander.xyz This bad boy here can fit so many still-adhered cells in it
Science Memes @mander.xyz Make sure to put it back once you're done using it
Science Memes @mander.xyz Inspired by another post
For anyone reading this who doesn't understand, shikata ga nai is a common saying in Japanese that literally translates to "nothing can be done." It's used very similarly to the English saying "it is what it is." It's not a reference insofar as just speaking in another language isn't really a reference to anything