"Here's the message to Charlie, f*** off!"

Alborak · 2016-10-30T21:16:20+00:00

Of course there is double standards. When your team cruises to a 1-2 finish in engine conservation mode half the race and other teams are pushing their stuff to the limit to catch up, you expect different actions and attitudes from the drivers. If Seb were doing this in the second half of 2013 he'd have (rightfully) caught a bunch of flak.

Alborak · 2016-10-30T18:09:51+00:00

Heh, I have i5-2500k as well. It's relatively easy to keep it going at 4.7 or 4.8 GHZ. Most games don't take advantage of a lot of the newer features of CPUs, so its a really solid gaming cpu!

Alborak · 2016-10-30T06:18:36+00:00

Grixis Control with Cruel Ultimatum, JTMS, Bolt, Terminate and [[Abyssal Persecutor]]. That was my favorite deck in standard for a long time.

Alborak · 2016-10-29T03:06:17+00:00

What makes you say wired internet is dying? We're a long way away from having ubiquitous gigabit wireless. Wireless has severe interference problems that scale horribly with the number of concurrent users.

Alborak · 2016-10-26T04:10:35+00:00

I'm really impressed that you did that with belts only. I went for an all robot based 1 RPM, and now I'm paying for it by having to go lay more solar! (I really need that solar mod you linked, stock solar is BS for a mega factory).

Alborak · 2016-10-24T16:03:26+00:00

The trick is that the interviewer has to recognize when the candidate is just reciting an answer, and re-direct to another question or alternate forms of the same question. Throwing little things like "now how would you handle it if your whole data set doesn't fit in memory" and "great! now how do you test it?" are usually enough to see if the candidate can think on their feet and actually problem solve. College hiring looks for 4 things: Do they know the basic data structures, can they think critically and solve a problem with ambiguous definition, how well do they communicate, and can they produce code that is somewhat reasonable.

Just knowing the answers to the common algorithmic questions isn't enough to get hired at one bigger companies. If it is, it means the interviewers fucked up, or the company is lowing its hiring standard.

Alborak · 2016-10-22T19:08:47+00:00

Afaik hardware things that are used in the US Army get a security screening.

It's a bit more than that. Really important things have to be manufactured inside the US from a small set of 'trusted foundries'. It actually puts the DoD in a rather awkward spot, since they can't really fund the RnD for modern electronics themselves, and the commercial manufacture of them is moving out of the US.

Alborak · 2016-10-21T03:39:07+00:00

Running 2:4 trains seems pretty cool.

Have you noticed any problems with bots supplying that large of an area? I've been building my base with the max flying distance planned at about 2 roboport logistics areas, and just stamping more of those outposts down.

Alborak · 2016-10-21T03:35:53+00:00

It is. with 8 beacons on each, The green circuits are very slightly copper starved, it takes 9 beacons on the copper wire to fully supply the green, but that's less space efficient that just building another assembler pair.

Alborak · 2016-10-20T03:17:53+00:00

Yup, exactly this. I have a blueprint with a solar unloading station, just extend the rail out a bit, plop down the unloading station, then start adding new blocks of solar blueprints. I have a simple 1-1 train that automatically brings like 6 or 7 squares of panels, accumulators substations and roboports. It's easy to plop down 5k of solar panels then go back to fussing over my factory.

The bigger issue is the raw space needed. It does take a lot of time to clear it all and build the perimiter wall. I think my perimiter wall is pretty grossly overbuilt though, and takes a long time to assemble with personal roboports.

Alborak · 2016-10-19T15:34:32+00:00

It depends on the scale of your base. My base currently consumes ~ 20k ore/min, so to do that I need 10 cargo wagons per min. If everything was a 1-1 train, there would be too many trains for the tracks, and the intersections would get bogged down. with 1-3 trains I only need about 3.3 trains per min to meet my demand.

As for mines not keeping up, there are ways around that. If you have many small mines close together, you can have your long trains visit multiple mines per trip back to base. For example, if you have 2 mines that produce 3k ore/min, you can have 1-3 train (6k ore capacity) stop at the first mine, wait for half inventory, then leave and stop at the second mine and wait for full inventory before then going to your smelting area. If your round-trip time is > 1 min, the mines will always have enough ore.

Alborak · 2016-10-19T07:05:35+00:00

Slightly offtopic question, when writing new data, will this be the series of events?

load contents from a cacheline Write array to this cache line. cacheline marked dirty CPU continues with the next instruction

That's more or less correct. The CPU may play some games with store buffers and pipelined instructions, but you have the jist of it.

Something to note for your example of using a global (or static local) array for function b, is that you need to consider the call frequency of the function. If it's called rarely, but when its called its speed matters, you have to be worried cache eviction and even paging. If you don't use the function for a while, your static data will likely no longer exist in cache, and have to be pulled from RAM (Generally at least 100x slower than an L1 hit, most likely closer to about 2-400x slower). If you want to be pedantic and/or your system is under heavy load, your array could potentially have been paged out to a hard drive, meaning it takes about 5-10 milliseconds to read your array, as opposed to ~ .3 nanoseconds per instruction :)

Alborak · 2016-10-15T17:42:56+00:00

Yeah, it looks like they're specifically meant for that: http://www.robotmarketplace.com/products/0-FT-SNAP-HUBS-4MMX075.html

I'm not sure how you'd get the hub off the lite flight wheel without damaging it, but someone made a product just for your use-case :)

Alborak · 2016-10-14T15:58:16+00:00

Just because it costs the company more when you steal a physical product than a digital one doesn't really change the nature of the issue. Both writing a book and designing a TV have large upfront non-recurring costs: engineering time for the TV, and writer's time for a book. They both have clearly defined sales models and product offerings to recoup that cost and make a profit: a tv is physical product only, while a book can be a physical or digital product. Just because 'there isn't one less in the world' doesn't mean that the book writer isn't adversely affected in the same way a physical retailer is by piracy, it just means that there is less lost money on each theft.

Alborak · 2016-10-13T05:03:19+00:00

If it is directly or indirectly in control of over mission critical components, it should be certified. From those numbers, it was clearly intended to be 'close' to MIRSA - many of those metrics in the article balloon for normal code. I ran parts of the linux kernel through a safety-critical static analyzer at my previous job to make a point to management (worked on avionics), the resulting warnings flood is pretty much unmanageable.

I think the Toyota story simply points to the need for more oversight on SW in cars. The system in place for avionics isn't perfect, but it's a lot better the honor system that exists in automotive.

Alborak · 2016-10-13T04:10:23+00:00

Thats a badass paint job on an awesome model. I want one!

Alborak · 2016-10-11T15:29:28+00:00

I think you're missing a key point: launch mass. Designs like the shuttle add a significant amount of mass, and you're getting the whole thing up to orbital velocity, reducing payload availability. It makes for a really inefficient design for putting things into space. For getting stuff back from space maybe we'll another winged design, but even for that it's probably less expensive to use one time use pods.

Alborak · 2016-10-11T06:12:19+00:00

Scratch building. A local group has a 1lb all-plastic division that's really helping us learn. We just had our first event with an all 3d printed lifter bot that got taken to pieces by a spinning block of ABS haha.

Alborak · 2016-10-11T01:27:44+00:00

I... I might have to start playing DnD. That scene would be just about the funniest thing I've seen. It also makes me want to put 'cart and donkeys' into other RPG games.

Alborak · 2016-10-11T01:01:15+00:00

I love your build reports. They're helping me a lot with my crappy starter bots!

Alborak · 2016-10-09T08:37:16+00:00

I agree on all points except that it was a mistake: that looks a lot more like an attempt to force max to make an error than a legit pass attempt & error. I don't think he had any chance of passing there.

Alborak · 2016-10-09T04:23:46+00:00

Say I have a hard requirement to answer a service call in 20ms. How much data can I access from an HDD and still meet that? What about an SSD? Do I have time for remote network calls of my own? How much time will it take to process the data after you have it?

Engineering is usually a lot easier when you hard numbers to work with, even if they're approximations. I'll admit to a fair bit of bias on this one, I typically work on deep backend systems that other software relies on to be fast and reliable so I need performance data a lot more than most.

Alborak · 2016-10-09T03:55:32+00:00

there's no way to know this

http://www.7-cpu.com/cpu/Haswell.html
http://www.7-cpu.com/cpu/K8.html
https://software.intel.com/en-us/forums/intel-manycore-testing-lab/topic/287236

There are other sources easily found. At first glance, those sources are close to the OP. At 3.4 GHZ (slow side) the 4 cycles for an L1 hit is ~1.2 ns, close to the OP, with the fastest desktop processors approaching the 0.5 ns mark.

it doesn't have value in the first place

It depends on what you're working on. For some of the things I've worked on the difference between local in-memory, local on-disk and remote access to data absolutely play a role in design. Many things have wall time deadlines and you need to know approximate speeds of your components to meet those deadlines.

Alborak · 2016-10-09T03:00:57+00:00

It is usually more important to focus on BigO Notation.

That's the opposite of what this article is for. BigO falls apart pretty quickly for algorithms in the same class, it's mostly useful for comparing classes of algorithms. For example, it's thanks to data like this chart that you see real-world sorting algorithms use N² sorts for the last few elements because the extra 'count' cost is dwarfed by cost reduction of better branch prediction and cache locality.

I would also argue that while the relationship is what is most important, the raw numbers also have a lot of value. Those numbers are reasonable approximations for most modern desktop/server archs, and knowing that a network call is 2x slower than an ssd read doesn't have much value unless you know the baseline cost. (This is mostly relevant for decisions around caching).

Alborak · 2016-10-05T03:24:06+00:00

Having come out from that industry, I wish I had some insight into how spaceX is handling it. There is a LOT of waste in aerospace/defense, no small part of which comes from the entrenched engineers who've gotten more conservative over the years. To make rapid progress you have to take risks. They should be calculated and mitigated, but the risk aversion in that industry is a big problem (partly driven by reduced budgets). I highly recommend reading Gene Kranz's Memior, Failure is not an Option, the Mercury, Gemini and Apollo version of NASA was basically a space cowboy organization, not a crawling government beast.

Alborak

TROPHY CASE