effie

Now he made a shallow acolyte video which seems like it should have been a paid marketing by the IBM mainframe division. I hope he got payed well, otherwise Dave is even more self-unaware that I thought. I get this is what Linus Tech Tips would do for a living, but really, a senior programmer with gobs of money is doing this superficial reporting on a what IBM told him on his trip there???

Seriously, this video (and YT comments it has) is a naive uncritical sucker reverberating most of the standard phrases from the mainframe sphere, although admittedly, with nice high-def shots of the machine components. I expected more serious adult commentary, not a teenage boy fan ravings.

Mainframes by IBM are a niche expensive product that is an interesting concept and history, but it is not an "amazing machine" to be put up today. There is no perspective for most young people working on mainframes, they will be phased out eventually. It's a solid product for the captured audience, which is like 2 banks and card payment processors, but that's it.

"Woo, they don't rely on ECC, they have multiple independent modules, because cosmic radiation, so cool" Get real, this is not an important problem, ECC works already, and good software has to account for occassional HW errors anyway.

I suspected as much. Thanks for saying so, maybe I'm not that out of touch yet.

This is not certain except for single threaded programs not accessing main memory, for which this claim is trivial and mostly academic. It is well-known that increase of frequency of CPU by a factor of k does not always result in equal factor k for increase of performance, mainly because of memory access speed not increasing in the same way.

"Appear faster" depends on instruction translation, exploitation of paralelism and memory access speed getting faster in some commensurate way, and nobody has yet built a machine doing those all those things at close to 30GHz to see how fast they are. It's possible that while very small CPU can possibly run at 30GHz, other bigger and more distant ingredients can't, e.g. main memory (heat and frequency causing too many errors to be practical). Already the present-day CPUs are too fast for the main memory they use. In intensive data processing, often CPU wastes most of the time waiting for memory. Making it wait faster won't help performance.

https://ir.amd.com/news-events/press-releases/detail/1146/am...

(of an action or situation) likely to arouse or incur resentment or anger in others. "she'd put herself in an invidious position" synonyms: unpleasant undesirable ungrateful

Pretty apt name, considering what the software does.

More generally, do you have to legally agree to Terms and Conditions to communicate with service provider's servers over HTTPS? Do you legally agree to them after you communicate one packet in such a way?

I don't think when Google crawls various websites, that Google has to agree to various licenses those website owners may have, or that its crawling of them implies such agreement.

It's ridiculous to believe that a magazine publisher, or a TV provider can require users to watch or hear the ads. Real life shows many people intentionally don't, using various methods, and I see no reason why Youtube provider should be different in this.

>

> Answer: “Sometimes yes, but only if you are seeking to avoid a ground loop. You likely don’t have to worry about this. If you are running shielded Ethernet between two structures that have their own separate AC systems or separate grounding rods installed, then YES, you should worry about what is known as a ground loop. A ground loop occurs when you have actual conflicting AC ground systems. Merely bonding your Ethernet cable at multiple points to the same AC grounding system in a single structure does not create ground loops. Think in terms of ground rods. How many ground rods are involved? If you have more than one with more than one structure involved then you are wise to bond to ground at a single end only.”

From https://www.truecable.com/blogs/cable-academy/residential-bo...

In a brushless DC magnet rotor, there is little energy loss, the magnets aren't very conductive.

Here, we have additional current and newly introduced Joule losses in the rotor. It is not clear that these can be kept low enough so the result is as good.

Stronger magnetic field due to high current in the rotor does not directly imply higher efficiency, it only directly implies higher torque, which gives the car higher acceleration. We don't need to increase this strength, current motors are plenty strong. This top torque mode of operation usually goes with decreased efficiency, due to high currents and high Joule losses. The best efficiency is likely to be achieved when ohmic and friction losses are kept low, thus currents as low as possible everywhere, induction coupling frequency dynamically governed to be at the optimal value dependent on the angular speed.

The only obvious advantage of the marketed motor is smaller size and likely lower weight. I'm afraid price will be a disadvantage.

The EM induction is present in the winding of the stator, and to some extent has to be present, to keep the current there low enough, otherwise we would get locked stator situation, and the winding would burn out.

Is there some way to specify that nothing except internal-sftp is allowed, as opposed to setting each option explicitly to "no"? The latter way seems error-prone, one is bound to miss some obscure option there.

And I wonder why do you suggest using the LOCAL6 log facility? In sftp-server, the default is AUTH...

FTP is close to such a thing, but it is somewhat archaic, slow and not sure about its security.

In the past they prevented people from running consumer GPUs on Xen systems.

https://www.thefpsreview.com/2022/10/20/intel-core-i9-13900k...

https://zsmith.co/bw-table.php

First row for Intel Core i7-930, DDR3 2000 MT/s he should be getting at most 16GB/s for reading from DRAM modules (not cache), but he's actually getting 18.4 GB/s, big 15% more. Maybe more cores were used, then the theoretical limit of that processor is 25.6GB/s, and the result is not that great.

But then for i5-520M, 1066MT/s he should be getting 8.5GB/s per core, but he's getting less, only 7.1GB/s.

Maybe contact the author (his email is in README.txt) and ask for clarifications on these discrepancies and help on your problem.

I think there is a problem somewhere with your system/measurements. With 6000 MT/s, there's no way getting 25GB/s is fine - that's what DDR4 3200MT/s should able to do. You should be getting close below 48 GB/s on one core, and 89.6GB/s multicore. And writes should be slower than reads.

https://zsmith.co/bandwidth.php

Make sure all power saving stuff is disabled in BIOS, that XMP is being used, and Linux is not booting with some weird ACPI/APIC flags. Try ganged/unganged mode (DCT) in BIOS.

One a 13900 core, with default clock, should be able to read at max. rate 89.2/2 = 44.8 GB/s (small gigabytes = 10^9). One DDR5 module running at 6000 MT/s has maximum throughput 48 GB/s. Granting some unknown slowdowns due to error corrections and other things I would be expecting to see at least above 40 GB/s. With two RAM modules and two or more cores working, one should be able to get above 80GB/s.

Perhaps memtest does something that limits its memory performance (maybe it uses old less-efficient instructions for reading memory instead of SSE/AVX) or maybe it makes a factor 2 error in calculation of the speed.

This, right here, screams the whole premise is nonsense. You don't label something very dangerous if you want to prevent primitive people from accessing it.

This project is not really about storing radioactive materials, but about the question "how do we spook stranger future people 10000 years from now so they won't dig here". Utter pseudo problem.

A high-level radioactive material ("waste" in the language of the current primitive nuclear technology prism) that you don't want to use anymore does not need "proper signage". Proper signage is needed only if you plan for people to access it.

If you really care that nobody can access it anymore, you dump it in inaccessible way, e.g. at big depth of Earth's crust at a not exactly known location, and then completely collapse the access holes. Most likely nobody will ever find it and get there.

If you do not really care about that (present governments), just dump it in a water pool near the power plant, or store it in a protected, easily accessible underground dry deposit. Much of "nuclear waste" is still a precious unburned nuclear fuel that people will want to use, after all.