# 4 Cores vs 8 Threads



## choLOL

Correct me if I am wrong here, guys.

[4 cores and 8 threads @5GHz] =/= 2.5GHz 8 core. It actually means 4 real, physical, existent cores and 4 "pseudo"/virtual cores @5GHz.

1.) I think not, it will use the first 4 real cores @5GHz, then the 4 other threads are idle.
2.) yes
3.) It depends, some programs use single threads, others are multi-threaded.


----------



## yuksel911

4 cores are enough for everything


----------



## Devilmaypoop

Quote:


> Originally Posted by *jcrandall623;13747577*
> Ok, I know this has already been talked about. Basically, if you have a 5GHz 4 Core / 8 Thread CPU, then it's virtually a 8 core 2.5GHz CPU. However, for this to be there would have to be 8 threads running.
> 
> 1) Is this statement correct? "In a 8 thread configuration, if there are 4 process threads running, there will be using only 2 cores/4 threads @ 2.5GHz."
> 
> 2) Inversely: "If a 4 core / 4 thread configuration, if there are 4 process threads running, it will use 4 cores / 4 threads @ 5GHz."
> 
> 3) Typically, do "everyday computing" require multiple threads or meater threads (5GHz thread vs 2.5GHz thread)?
> 
> If I'm way off, then please explain to me how cores and threads work. Thanks.


1. No. It's 4 real cores running at 5ghz and 4 virtual threads running at 5ghz. Although the effective speed for the virtual threads will be massively less than real threads.

2. Yes.


----------



## Scorpii

The hyperthreaded cores are not nearly as powerful as the 'real' cores, but they still add to performance. so running 4 'real' cores and 4 hyperthreaded cores at 5GHz gives you a reasonable amount more power than just 4 real cores, but not as much as 8 real cores (at least in highly multithreaded applications).

It doesn't halve the effective power of each real core, as it uses a method of utilising extra CPU power that wouldn't otherwise be utilised on each 'tick' of the CPU.

Your last question is a little more involved to answer (except for pointing out again that it doesn't work like you asked, with the clock speed halving). Most applications do not need or utilise 8 threads, and it has been posited that hyperthreading actually slightly reduces performance in things like games or some other applications. Certainly at least hyperthreading tends to lower your maximum possible overclock (as it requires more power, hence you reach clock speed limit before you would otherwise), and for many applications you'd be better off with, say, HT off at 5GHz than HT on at 4.5 GHz (for example)

However, for highly multithreaded applications like encoding, rendering etc hyperthreading tends to help a lot.


----------



## mrcool63

but for rendering and 3d isnt 8 cores more better than 4 cores with HT? im highly confused here? will it not result in severe data crashing?


----------



## ____

Cinebench: i7 2600K

4C/4T: 6.03
4C/8T: 8.55
Single: 1.78
*Ratio 1T/8T: 4.8x*

Ideally, the ratio should be 8x, but it's closer to 4x. That means there's only a 20% gain.


----------



## Devilmaypoop

Quote:


> Originally Posted by *mrcool63;13759976*
> but for rendering and 3d isnt 8 cores more better than 4 cores with HT?


Yes, multiple times better, but HT is very cheap to make, cores are not.


----------



## DuckieHo

Quote:


> Originally Posted by *____;13760155*
> Cinebench: i7 2600K
> 
> 4C/4T: 6.03
> 4C/8T: 8.55
> Single: 1.78
> *Ratio 1T/8T: 4.8x*
> 
> Ideally, the ratio should be 8x, but it's closer to 4x. That means there's only a 20% gain.


20% gain for less than 10% silicon cost and only requiring a few watts more.








Quote:


> Originally Posted by *Devilmaypoop;13772098*
> Yes, multiple times better, but HT is very cheap to make, cores are not.


Exactly.


----------



## Asmodean

Personally, if i was to go higher then a quad, id go for the 8 cores, rather then threads, but at least for now, 4 cores are more then anough for most things, unless your in the encoding, VM's etc business. HT _seems_ more of a burden then a help for some things. But its still much better then a quad core, for desktop processing tasks etc.


----------



## WhiteDragon32

Quote:


> Originally Posted by *Scorpii;13747815*
> The hyperthreaded cores are not nearly as powerful as the 'real' cores, but they still add to performance. so running 4 'real' cores and 4 hyperthreaded cores at 5GHz gives you a reasonable amount more power than just 4 real cores, but not as much as 8 real cores (at least in highly multithreaded applications).
> 
> It doesn't halve the effective power of each real core, as it uses a method of utilising extra CPU power that wouldn't otherwise be utilised on each 'tick' of the CPU.
> 
> Your last question is a little more involved to answer (except for pointing out again that it doesn't work like you asked, with the clock speed halving). Most applications do not need or utilise 8 threads, and it has been posited that hyperthreading actually slightly reduces performance in things like games or some other applications. Certainly at least hyperthreading tends to lower your maximum possible overclock (as it requires more power, hence you reach clock speed limit before you would otherwise), and for many applications you'd be better off with, say, HT off at 5GHz than HT on at 4.5 GHz (for example)
> 
> However, for highly multithreaded applications like encoding, rendering etc hyperthreading tends to help a lot.


On the games couldn't u just set up the game to use the 4 real cores via affinity option in task manager and then wouldn't that let the game perform like it would if u had HTT set to OFF?


----------

