What is Hyper Threading Technology as Fast As Possible

Intel's Hyper-Threading Technology allows their processors to intelligently schedule the tasks that are performed by a single core to make data processing more efficient. Watch the video to learn more of course ;)

[XxmecaxX]

Your food analogy really made this so easy to understand. Thanks Linus! Now I'm going to get some pizza.

[Raptor]

First I was just confused. Now I'm confused and hungry. Thanks.

[PozdraviteKevu]

"In an ideal world, lots of physical processors, each with hyperthredding, is where it's at"
Fast forward to 2021 when we can get reasonably fast 8 cores 16 thread processors for 300$
I really love watching old tech vids because it feels like I'm from the future

[Rakshasa]

I hyper threaded 2 slices of cheese pizza for dinner today.

[laymanexpert]

so: 4 cores with 4 threads > 2 cores and 4 threads?

[Manysdugjohn]

In an Ideal world lots of physical processors each with hyperthreading, is were its at.
AMD : YES.

[hababhalil]

dude. i've been watching your vids from this channel and linustechtips and ncix techtips for the past few weeks. i've always love all about computer but never really know much about them. your videos really helps me understand the basic. thank you.

[Xilver_]

so lets review: what is hyperthreading? "Sewing really fast"

[TheMaggots]

so hyper threading has to do with food?

[wenqiweiabcd]

The hand-mouth analogy is actually perfect for explaining the fetch-execute cycle, but having two hands has little to do with simultaneous multithreading; it's analogous to increasing the memory bandwidth, i.e. the amount of food that can be delivered to the mouth per minute.

[SethanderWald]

9 years later, and this mouth/hand eating analogy is still by far the best way I've heard to explain hyper threading. :)

[georgegeoffrick]

Linus: OK speaking of...
Me : ok time to go

[talkysassis]

The part of decrease is real. I wrote a quicksort program in c using openmp, and put an argument to limit the thread number to the value I want. Running this on a i7 dual core 4 threads was way faster on 2 threads than on 4. That's because in 2 threads, when I split the program in two cores, they execute it directly, but on 4 threads, they where always changing process, and that made them slower.
Hyper-thread is good for very small, parallel tasks, and not to split heavy ones.

[DrRChandra]

Think of it more this way...HyperThreading uses pieces of the processor which are not otherwise in use.  For example, if an instruction for a floating point multiply of one floating register with another is followed by a memory fetch to an integer register, while the FPU is computing the product, the memory fetch circuitry would be otherwise unused/idle.  So instead of waiting for the FPU to finish, the memory fetch goes straight to the ALU, thus executing a floating multiply and the memory fetch at the same time.  Obviously, this can only be scheduled thusly if there are no conflicts, for example the floating multiply cannot reference the same memory area as output which is being fetched in the next instruction (which is why above I specified the FPU was working with registers).

[pauls]

Wow! I have a great example of this. Just last week, I took a process I have and made it into a multithreaded process. It's the building of a navigation mesh for pathfinding in video games. The process I started with was single threaded and it took 52 minutes to build for my huge level. I made it work on building two tiles at once and this brought it down to 26 minutes exactly. Then, I made it use 4 threads and, as expected, the build time dropped to 13 minutes! WOW!

I know that it's only a quad core so, if I try for more than 4 threads, it's going to try to use hyper threading. What the heck, let's try! 6 threads....12 minutes!! :( 8 threads, 11.5 minutes! HA... hyper threading didn't help me much at all. More CORES freakin' rules!

[gabriellopez]

This was really informative and easily understood, thanks Linus! I still haven't stopped learning from you yet, even after almost three years.

[bccabernet]

this was really helpful. I always assumed I needed a more "powerful" processor because I watch dvd& bluray movies (I rip my discs and watch the mkv files) and stream online. I do a bit of photo editing, but that's about it. I play no games. And I had no idea what the terms core or hyper threading meant until I watched your videos. Thanks.. you make learning about computers exciting and easy to understand. It's not such a scary world afterall..

[jetjazz]

I remember the advent of dual cores, it was a massive breakthrough in computing for the average consumer. At that point in time waiting for common things like browsers, media players, and folders basically went extinct. The ability of the computer to have a free processor open for you to access those things instantly meant that it didn't have to drop background processing to open the program you'd requested. Even going from a 3.8ghz single core to a 1.86ghz dual core is a big improvement just because of this fact.

[DarkKillerMMO]

Linus is a cpu CONFIRMED..Spread the truth

[WoundedEgo]

Oh, I thought this was about sewing...