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24-core CPU and I can’t move my mouse (2017)

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Re: 24-core CPU and I can’t move my mouse (2017)

#241

Post by mixmastamyk »

_Algernon_ wrote: post #61
mixmastamyk wrote: post #40

Earlier quoted context omitted.

Can still be done if all you want is a command-line to come up and be responsive. Most folks want web, email, images, and even a bit of security from their computer today. Could always be faster, but I think the days of "bam!" ready are past due to those requirements. Unless the computer is only sleeping, like an iphone for example.

>Most folks want web, email, images, and even a bit of security from their computer today. Could always be faster, but I think the days of "bam!" ready are past due to those requirements. Unless the computer is only sleeping, like an iphone for example. Sure, but a modern computer also has orders of magnitude more processing power than devices that only ran a command line. There is no reason that we cant have both, e…

Folks will pay for simple and ready immediately, or complicated, multi-user, and rich in a minute. (Plus significant backwards compat.) There is no big need for complicated and ready now. Pulling in the long tail of functionality often desired takes time, and it is mostly IO-bound not CPU bound, which hasn't increased as fast.

I suppose you could put a ton of OS and libraries in a (modern equiv of EEP)ROM for immediate access. The original Macintosh was kinda like that. But things went the other way when disk storage dropped in price a lot faster than chip storage.

Maybe we're back to a point where the former is economically viable, but there would be a lot of historic baggage to overcome.

Re: 24-core CPU and I can’t move my mouse (2017)

#242

Post by NobodyNada »

turol wrote: post #228
NobodyNada wrote: post #39

In the follow-up blog post ( https://randomascii.wordpress.com/2017/07/27/what-is-windows... ) he uses a sampler to try to find the bottleneck by looking at CPU instructions, but concludes: > But the main thing I always realize when using this technique is that modern CPUs are weird and confusing. Because CPUs are massively out-of-order and super-scalar it is not at all clear what it means for a sampling interrupt to…

It was Travis Downs: https://travisdowns.github.io/blog/2019/08/20/interrupts.htm...

That’s it, thank you so much!

Re: 24-core CPU and I can’t move my mouse (2017)

#243

Post by Oxidation »

Razengan wrote: post #135

Why don’t computer architectures have a separate CPU dedicated to the OS/GUI?

This will still not help when the UI CPU is busy-waiting for the application CPU to generate and send the contents of the menu after you click.

And if you can asynchronise separate CPUs, you can do it in separate threads on one CPU.

Re: 24-core CPU and I can’t move my mouse (2017)

#244

Post by rbanffy »

nailer wrote: post #235
rbanffy wrote: post #230

Earlier quoted context omitted.

This will probably change as we get more cores and performance/efficiency ones. Macs already run a lot of the low-priority tasks on their slow cores leaving the fast ones available for interactive activities. I don't disagree on the current approach though. If I start a, say, long build job from a terminal window, I have control over the resources it can take. If, OTOH, I start a program from the GUI, it's reasonable…

More cores won’t fix it. Some app will add more processes and use all available CPUs and there’s no reservations. You had it right with nice - phones and tablets and consoles and cars have it right with their techniques. Apps shouldn’t be able to make the system unusable by default.

> More cores won’t fix it.

By themselves, no, but there are limits to how many cores a workload can keep fed. You'll see declining returns at high core counts (which is one of the reasons we don't have Xeon Phis these days).

Re: 24-core CPU and I can’t move my mouse (2017)

#245

Post by int_19h »

scapp wrote: post #162
int_19h wrote: post #147

Earlier quoted context omitted.

I wish Ctrl+Alt+Delete would be reliable enough to work with full-screen games. But, half the time, when you try to launch Task Manager that way to kill the offending process, it ends up under the game's output. I've learned to kill processes using keyboard navigation by looking at Task Manager's thumbnail in Alt-Tab process list, but it's ridiculous that we still need to do this kind of dance in 2023.

There's a way to make it always appear above other windows. Let me see if I can find that again... Ah, it's in the options menu on the task manager itself (alt + O to access the menu without a mouse).

The problem is that it doesn't work reliably when a fullscreen game that is currently using the screen exclusively for itself suddenly crashes.

Re: 24-core CPU and I can’t move my mouse (2017)

#246

Post by bcrl »

zozbot234 wrote: post #225
bcrl wrote: post #223

Earlier quoted context omitted.

The Amiga's built in serial port was particularly atrocious as the hardware could only buffer 1 character at a time. This meant that it did not work particularly well at baud rates above 9600. Combined with the CPU being starved from accessing RAM when running in hires 16 colour modes (used when emulating ANSI "graphics" common at BBSes back then), this made it rather unpleasant as a terminal emulator.

The Amiga supported both chip and fast RAM, precisely to solve the problem you're talking about. What you mention here was at most an issue with your particular machine, not a limit of the platform itself.

No, that doesn't solve the problem -- I had a few megabytes of fast RAM, and it still sucked. The chipset bus is completely contended in 4 bitplane high res graphics in OCS/ECS, so any attempt to access the serial port registers is blocked until the horizontal blanking interval (as is chip or slow RAM). The faster and wider data path in the AGA chipset improved this substantially, but that data path was only used for video DMA, not for the blitter or other chipset register accesses. The only real solution was to use an aftermarket serial port card that wasn't on the chipset bus and used a real UART like the 16550 that had a 16 byte FIFO.

Re: 24-core CPU and I can’t move my mouse (2017)

#247

Post by brucedawson »

Sohcahtoa82 wrote: post #49
bakugo wrote: post #30

Earlier quoted context omitted.

> I can't think of a good principled reason to say SMT cores aren't "real". It really depends on your definition of "real", yes you can treat them like "real" independent cores but that's not ideal for performance because under the hood they're not actually independent. Your operating system is aware of this and will often avoid scheduling two tasks onto the same physical core unless it has to. If you have 20 logical…

I did an experiment and effectively proved this to myself many years ago. I had just upgraded to an i7-3770K (8 threads, 4 cores) from a Core 2 Quad (4 threads, 4 cores). I did a POV-Ray render several times using 1, 2, 4, and 8 threads. 2 was nearly double the speed of 1, 4 was nearly double the speed of 2, but 8 was only about 15% faster than 4. To ensure I wasn't bottlenecking RAM at that level, I tried again with…

An underappreciated consequence of this is that if doubling the number of cores doubles performance (meaning the multi-threading is good) but going on to the hyperthreads only gives a 15% speedup then that means that in the hyperthreaded case each hyperthread must be running 57.5% of normal speed - barely half as fast. That's just math.

This slowdown of each thread may not matter, or it may lead to increased latency.

TL;DR - when both hyperthreads in a core are in use it is highly likely that each one is running significantly slower than if only one was in use.

Re: 24-core CPU and I can’t move my mouse (2017)

#248

Post by NikkiA »

jacquesm wrote: post #186
dijit wrote: post #141

Earlier quoted context omitted.

The boot was fast on the c64. Essentially instant. It just dumped you into a prompt though, and loading any program was really quite painfully slow.

It could be just as fast if the bios on a PC did absolutely nothing other than initialize the motherboard and a small basic interpreter. A modern bios goes through more cycles during the boot phase of a typical machine than a C64 would see in its entire lifetime.

On early IBM PCs (up until around the introduction of the PS/2 anyway) there was a key sequence to boot direct to BASICA, and it was always about as fast as the 8bits were - except that most of the 8bits didn't have the slow memory check that IBM insisted on.

Re: 24-core CPU and I can’t move my mouse (2017)

#249

Post by deterministic »

WalterBright wrote: post #44

I use Thunderbird for my email. Its behavior shows it is a multithreaded program. But often, the mouse and keyboard will freeze and it becomes unresponsive for several seconds. This is indicative of suboptimal partitioning of the tasks into threads. The highest priority thread should be responding to user input. Heck, back in the 1970s, I designed and built a single board computer that was to be a glass tty. There wa…

It just shows that Thunderbird has room for improvement when it comes to how it uses multi-threading. You always want the UI thread to be non-blocking and react instantly when a user does something. Most games (for example) do this really well.

Re: 24-core CPU and I can’t move my mouse (2017)

#250

Post by [deleted] »

andrewstuart wrote: post #64

This is one of the primary resaons I ditched Windows for Macos. The multitasking on Windows is ridiculously bad. Also, applications that freeze and can't be killed/restarted are simply part of life on Windows. Add to all that, Window slows down over time - again, the periodic reformat and rebuild is part of life on Windows. After I switched to Mac I didn't need to rebuild the operating system essentially ever. Also,…

[deleted]
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