The following link has some charts for just the ethanol. They look about as expected. Some things get better the more ethanol you use, some get diminishing returns, some have an inflection point and get worse, some are just worse as you increase ethanol percentage.
Fundamentally, ethanol will always be less efficient per gallon than gasoline. It has significantly less specific energy compared to gasoline. This is a fact known by anyone that has tried e85 either for racing or for flex fuel compatible normal vehicles.
But look at figure 8. At 40%, volumetric efficiency is at its peak. It's very important to note that these results are neither monotonic nor linear, so while the public only has access to E85 and E10/E15 (at least where I've been), those are almost ends of extremes and a middle ground can synergize. Yes some metrics always get worse the more ethanol you use, but hopefully you looked at the paper and saw that isn't nearly the full story.
I'm not sure what that proves? Volumetric efficiency is just about air efficiency. Higher VE is better, yes, but you need to compensate for higher VE by adding more fuel to utilize the air, otherwise you run lean, which is bad. Turbocharging a car, for instance, directly increases VE.
None of this directly equates to fuel efficiency although it can be related, which is what the GP was asking about presumably. You still need to content with the fact that ethanol has ~30% less specific energy per gallon.
Figures 8 and 9 show that both volumetric and thermal efficiency can be improved with nonzero ethanol in the right circumstances. Increasing efficiency metrics, while combining figure 7's showing that you get more power with ethanol, means that you're getting more power and doing so with greater efficiency.
You mention fuel efficiency. Figure 6 shows that in some cases, looks like the threshold is between 60 and 80% load, the story flips such that adding ethanol to the mixture reduces sfc. In other words, less fuel is needed for the same amount of power. Meaning, if it takes X hp or kw to sustain whatever test speed you're measuring efficiency at, the amount of fuel you use is lowered. I think this is very important to understand. Figure 6 shows that if your engine is sufficiently loaded, nonzero ethanol can improve the amount of energy you get out of the same mass of fuel relative to pure gasoline, which I believe would be directly proportional to better fuel efficiency.
Now very notably, if less heavily loaded, it seems better to use 0 ethanol. The ability to choose lets it get the best of both worlds.
> America put men on the moon without millions of foreign immigrants
Did you drop out of middle school?
America saw the highest rate of immigration in history between ~1910-1960. A majority of the scientists and engineers in the Apollo program were immigrants or children of immigrants.
> Why is it only ever white nations that are expected to let everyone else in?
They are not, have you considered moving to Russia?
Personally I use eBay and find the most barebones system I can, then populate the CPU+RAM with components salvaged from e-wasted servers. There are risks with this, as I've had to return more than one badly-bent workstation that was packed poorly.
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So the Dell Precision T7920 runs dual Intel Scalable (Skylake) and has oodles of DIMM slots (24!), but you'll need to use a PCIe adapter to run an NVMe drive. FlexBays give you hot-swappable SATA, SAS too but only if you're lucky enough to find a system with an HBA (or add one yourself). But if you manage to salvage 24x 64GB DDR4 DIMMs, you'll have a system with a terabyte-and-a-half of ECC RAM - just expect to deal with a very long initial POST and a lot of blink codes when you encounter bad sticks. The power supply is proprietary, but can be swapped from the outside.
The T7820 is the single-CPU version, and has only 6 DIMM slots. But it is more amenable to gaming (one NUMA domain), and I have gifted a couple to friends.
If you're feeling cheap and are okay with the previous generation, the Haswell/Broadwell-based T7910 is also serviceable - but expect to rename the UEFI image to boot Linux from NVMe, and it's much less power efficient if you don't pick an E5 v4 revision CPU. I used a fully-loaded T7910 as a BYOD workstation at a previous job, worked great as a test environment.
Lenovo ThinkStation P920 Tower has fewer DIMM slots (16) than the T7920, but has on-motherboard m.2 NVMe connectors and three full 5.25" bays. I loaded one with Linux Mint for my mother's business, she runs the last non-cloud version QuickBooks in a beefy network-isolated Windows VM and it works great for that. Another friend runs one of these with Proxmox as a homelab-in-a-box.
The HP Z6 G4 is also a thing, though I personally haven't played with one yet. I do use a salvaged HP Z440 workstation with a modest 256GB RAM (don't forget the memory cooler!) and a 3090 as my ersatz kitchen table AI server.
>and a lot of blink codes when you encounter bad sticks
Which sadly happens quite a lot with ECC DDR4 for whatever reason.
>If you're feeling cheap and are okay with the previous generation, the Haswell/Broadwell-based T7910 is also serviceable
The T5810 is a known machine, very tinkerable, just works with NVMe adapters (they show up as a normal NVMe boot option in UEFI) and even have TPM 2.0 (!!!) after a BIOS update. Overall, they are the 2nd best affordable Haswell-EP workstations after the HP Z440 in my opinion.
>E5 v4 revision CPU
They are less efficient than V3 CPUs due to the lockdown of Turbo Boost, but then again on a Precision you'd have to flash the BIOS with an external flasher regardless to get TB back.
Forgot about Dell gimping Turbo Boost on that firmware.
Another route is the PowerEdge T440 (tower server), which does respect Broadwell-EP turbo logic without a reflash. Not quite as quiet as a workstation, though.
It's funny how machine code is a high level language nowadays, for this example the CPU recognizes the zeroing pattern and does something quite a bit different.
It's really impressive how powerful and efficient it has become. However, I find it so much more difficult to build mental model of it. I've been struggling with atomic and r/w barrier as there are sooo many ways the instructions could've been executed (or not executed!).
It's a consequence of keeping our general purpose single threaded programming model the same for five decades.
It has it's merits, but the underlying hardware has changed.
Intel tried to push this responsibility to the compiler with Itanium but that failed catastrophicically, so we're back to the CPU pretending it's 1985.
What do you mean that cpu does something different? Isnt cpu doing what is being asked, that being xor with consequence of zeroing when given two same values.
I think OP means that it has come a long way from the simple mental model of µops being a direct execution of operations and with all the register renamings and so on
> And, having done that it removes the operation from the execution queue - that is the xor takes zero execution cycles!1 It’s essentially optimised out by the CPU
> with consequence of zeroing when given two same values
Right, it has the same consequence, but it doesn't actually perform the stated operation. ASM is just a now just a high level language that tells the computer to "please give me the same state that a PDP-11-like computer would give me upon executing these instructions."
But it will not execute xor, nor will it actually zero out eax in most cases.
It'll do something similar to constant propagation with the information that whenever xor eax, eax occurs; all uses of eax go through a simpler execution path until eax is overwritten.
Yeah someone joining a good company as a senior engineer in 2015 would retire with about 15M in assets now assuming smart investments (say... half on big tech stocks, half in market indices)
Someone joining now on the other hand, might have to resort to physical work at some point in the next ten years of things go south.
If you are working for boring old enterprise companies like banks, airlines, insurance companies or even most YC funded companies, “senior” developers will top out at around $160K-$170K inflation adjusted in tier 2 cities.
I spent my pure developer career [1] in Atlanta GA. Well known companies based there like Home Depot, Delta, Coke, and GE Transportation are paying their top developers around what entry level developers getting in BigTech.
But choose your non west coast city and you will see the same.
Sure, just save 100k out of your 170k comp, that's totally how normal people operate. And not only that, also pick the right stocks rather than just sticking everything in an index!
I haven't got to 10m yet, but I saved 70-80% of my take home pay since ~2008 and I have enough to quit at any time and live the rest of my life without working. That is just by investing in the 3-fund portfolio and without the crazy SF salaries.
Before Covid, I lived on about 25K a year since I had a paid off condo then. Now, I am renting and live on around 36K a year. I realize my situation doesn't work for everyone. Some people cannot fathom not buying a new phone and computer every year and a new car every 3 years.
Also, now, I am fully working from home so that helps with saving on gas and not eating out as much. I make my coffee every morning instead of Starbucks on the way to work and I make my own lunch and dinner 95% of the time.
You could have looked up the numbers for indices yourself, but here you go -
S&P500 -> ~4 million
NDXT (top 100 tech) -> ~14 million.
> just save 100k out of your 170k comp
Yes, that was my starting salary, and that's almost exactly what I saved.
This calculation assumes your salary is somewhat constant and maxed out as the person I was responding to claimed, but in my experience you can expect your tech salary to double every ~5-6 years.
NDXT went from ~2300 in 2015 to ~12500 in 2025. That's ~5.5x return. So even if you had your whole 1M saving in 2015, you'd only have 5.5M now. No idea how you get nearly 3x that?
And it's way worse if you take the actual scenario which is 100k added every year instead of starting with the 1M.
S&P500 is worse yet, at about 3.5x total return if you had the whole million at the start.
Really appreciate your comment, literally the only comment in this long sub-thread that picked up on the nonsensical numbers fooker put out.
Realistically fooker's investment strategy into NDXT of 100k over 10 years would have produced around $2.5M depending on exact timing in the year and partitioning of that 100k. Way less than $15M nonsense. Also would have required extreme conviction alike the crypto types and completely counter how typically multi-million portfolios are managed (diversified).
Also, who needs 15M, at 5M net wealth there honestly is no reason to be working at a $200k/year job. You'll make way more after-tax income even assuming lousy 5% yearly return thru capital gains. Same story for 2.5M @ 10%.
Counting on 10% returns long term is way to aggressive especially when you have to consider sequence of returns risks during withdrawals. Even 5% is not conservative enough while you are in the withdrawal phase.
If I had $5 million of investments outside of my home, would I work? Maybe? My job is far from stressful, I work from home, I “retired” my wife over 5 years ago when she was 44 eight years into our marriage so she could pursue her passions and we could travel a lot.
All of my friends still work so what could I possibly do with my free time that I don’t do now? The only restrictions that not working would lift is that we could more easily spend an extended amount of time outside of US time zones.
> Counting on 10% returns long term is way to aggressive especially when you have to consider sequence of returns risks during withdrawals
Yes though the propose is not to retire. There's better things to do with your life (IMO) than work a standard 9-5 job for some corporation once you've accumulated sufficient wealth to have financial independence.
> Even 5% is not conservative enough while you are in the withdrawal phase.
Assuming you spend 5% per year. 5M@5% is 250k, 200k+ after tax for CG + eligible divs. That's a lot of money to spend every year, more than most families get to earn thru their labor yearly. Can be secured against downturns with higher 4%+ bond allocations too. 5M is financial independence for vast majority of households. 2.5M can be as well for many if their baseline spend remains at 100k.
> All of my friends still work so what could I possibly do with my free time that I don’t do now?
Financial independence provides vast opportunities for those with ideas but lacking time. There's a reason most businesses are pursued by those who have financial wealth on their side.
That’s true. I said “top out at”. When I left AWS working in the ProServe (cloud consulting division) in 2023, I was seeing “architect” positions in Atlanta - I didn’t live there any more, but most of my network was still there - topping out at $175k. But for “senior” developers it was even less.
I obviously decided to stay in consulting and work full time for a third party consulting company.
$170K a year after taxes is $9900 a month net if you are living in GA - with fairly low state taxes. I calculated this on paycheckcity.com. That’s without taking into account health insurance cost.
So to invest $100K a year let’s say some pretax and some post tax, they would have to live off of $1700 a month. They are not going to be buying a house with that.
As far as wealth through equity in a house, that’s not liquid. What are you going to do borrow against it?
And actually I can speak for one of the best case scenarios for buying a house. I had a house built in 2016 in the most affluent county in GA for $335K - a 5 bedroom, 3.5 bath - and sold it in 2024 for $670K and moved to state taxe free Florida and bought a condo in 2022 for half the cost (we kept both for awhile)
Even then, we could only do that because my (step)kids were both grown and I pivoted to customer facing cloud consulting in 2020. A niche that hasn’t suffered from the return to office mandates - ironically enough except for AWS ProServe (former employee) and Google’s equivalent internal department (who has been trying to recruit me for years).
Most people won’t and shouldn’t be picking individual stocks. Of course it’s easy to be a genuis saying what would have happened if you picked stocks that went up.
> There are plenty of people who have managed to do this, from fairly normal tech jobs.
Yeah, but there also isn’t enough wealth in the system for everyone to do this.
Like suppose that a) we’re now at a reasonably correct valuation for Nvidia b) assume a hypothetical where everyone in the US had plowed all of their savings into Nvidia in 2015. Result: The market cap of Nvidia is still $6 trillion, and the median American owns less than $10k in Nvidia stock.
Sure, but there was nothing stopping people with $10k in savings in 2015 from buying Nvidia. If someone with $10k in savings had bought Nvidia in 2015, they’d have $2.5m today. But that only works for a relatively small number of people before the $2.5m is no longer $2.5m - they’re all drawing from the same $6 trillion pot. “Everyone with a good tech job” is accurate, but besides the point, it would work exactly the same if you limited it to “everyone who’s a plumber” or “everyone who’s a fedex driver”, but literally cannot work for everyone at the same time.
> it would work exactly the same if you limited it to “everyone who’s a plumber” or “everyone who’s a fedex driver”
Yes, "Everyone with a good tech job" has a significantly higher chance of keeping or holding tech RSUs, and have conviction that investing in tech is going to pay off.
> but literally cannot work for everyone at the same time
Yes, that is how the world works. Anything that makes you successful would not work for everyone at the same time.
> Yes, that is how the world works. Anything that makes you successful would not work for everyone at the same time.
To me this reads as a particularly misanthropic view of the world that only considers zero-sum (or less than zero sum) actions.
Any investments in yourself that aren’t at the expense of others (education, exercise, diet, therapy, living space improvements, etc., etc.) or investments in family and community, benefit both you and others and would work for everybody; indeed, many such investments would work better the more people undertook them, rather than the fewer.
If more people bought Nvidia stocks, the value would be higher. If everyone bought, something would give (and that is exactly what we are starting to see).
170k after taxes leaves you with about 130k net, maybe 140k; if you live in a big city and have a family, it's almost impossible to save 100 grand of that 140k. More realistic you would save about 50k and still come out ok, but lets be realistic noone is saving 100k from 170k gross salary
In GA, after taxes your take home would be ~125k. So you think someone can live in a big city like ATL for 25k/year? What if they have a family? Ok, are you assuming their spouse is also in tech and making at least similar? The 125k also doesn't have healthcare deducted yet.
Some of the comments on this thread highlight just how disconnected many people were/are from everything outside of the FAANG bubble.
If you live in an expensive city and do not have a proportional salary, obviously you are going to save less.
> Ok, are you assuming their spouse is also in tech and making at least similar?
Yes, suppose spouse contributes to household expenses, but assume separate savings and investments for this calculation. Do you see you'd easily get to 100k saved?
The difference between having a large fraction of your savings in your bank account versus invested for the last 10 years can be quite a few millions, which is what most commenters here are failing to see. I'm sure the story was different between 2002 and 2012, but that was not what I talking about.
Ok, so you need 2 people working in tech making near top end salaries for the area? You do see how this simple idea of saving 100k/year isn't so simple for anyone outside of FAANG?
I managed to save about 100k per year in Denver and Salt Lake City with mid tier tech and govt lab jobs. I'm suspicious of the claim that Atlanta is significantly different. From what I have seen, it's usually bad financial decisions.
And for context, saving about double that during and post COVID by obtaining a remote job where the employer does not discriminate by location too much other than for maybe career growth.
I posted calculations. $170K a year after taxes is $9900 a month before health insurance. To save $100K a year since only some of it would be pretax means you are living off of around $1600 a month.
And while I work remotely, remote jobs are getting more scarce and more competitive. Every job gets hundreds of applications within the curse few hours.
> If you live in an expensive city and do not have a proportional salary, obviously you are going to save less.
I assure you that my hometown in South GA (a cheap city) didn’t have $170K a year developer jobs.
A friend who moved to Columbus GA after college in 1997 I doubt is making $170K now.
I know my friend who still lives in Atlanta and is a lead developer at Home Depot (one of the few F500 companies based in Atlanta) just crossed around $170K and he has been there 10 years.
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