What is physical core and logical core? + What better ?

[keavlar]

Hey guys. Could you please explain me in simple way:

1-What is physical core and logical core?  (I did read about, but wanna have another explanation)

2-When buying laptop or PC CPU, for better performance, what should I concentrate on?

3-Here I have example  : # of Physical Cores: &nbsp;<6 (2 logical cores per physical) > VS <4 (2 logical cores per physical)> 

should I look for Computer with more Physical Cores?  Or there is also a cpu with 4 logical Cores ?

 

Thank you in advance

 

 

 

[Enderman]

'logical cores' are called threads.

An 8 core CPU is better than a 4 core 8 thread CPU assuming same manufacturer and generation and frequency and all other specs identical.

An 8 core CPU is worse than an 8 core 16 thread CPU if everything else is identical too.

[suchamoneypit]

First know of a tech called called SMT, simultaneous multi-threading. Essentially it allows a single physical core, to do two calculations at once. For example, a 4690K has 4 cores, all 4 are physical. however a 4790k has Intel's Hyperthreading (Intel's SMT technology), so each core can do two things at once, so it has 4 physical cores, 8 logical cores. People would refer to this as a 4/8 CPU or 4 cores/8 threads. A Ryzen 7 1700x has 8 cores, with SMT technology, so I have 16 threads total (8/16). Most things refer to your "Logical" cores as the total cores the systems views. For example, to a program, in the case of a ryzen 1700x, it just views you as having 16 cores. Although you really only have 8 physical cores, since you have SMT, the system views this as a "logical" 16 total cores because its going to see and send data to CPU cores 0-15 (16 cores total) as they all can do things. 

[keavlar]

7 minutes ago, Enderman said:

An 8 core CPU is worse than an 8 core 16 thread CPU if everything else is identical too.

Wait, what?! 

Shouldn't they be the same!!??

[Enderman]

3 minutes ago, keavlar said:

Wait, what?! 

Shouldn't they be the same!!??

Nope.

Look at 9700K vs 9900K.

The 9900K has hyperthreading and that allows it to outperform the 9700K in multithreaded tasks, because it essentially can do 16 things at the same time instead of 8.

[SupaKomputa]

1. physical core is the real core that the cpu has, logical core is how many is how many execution it can perform per core, this is usually called multi-threading. Say if a core doing task only used 70% of its capacity, 30% is left unused, with multithread, you can use what's left to calculate another task.

2. All mattered, the CPU, GPU, Memory, Harddrive. You should concentrate on these 4.

- CPU, the more GHZ and more cores / threads the better. Depending on the task, Gaming favors high GHZ, while productivity task favors more threads.

- GPU, the performance usually scaled up with price, similar priced gpu will most likely perform the same. There are 4 different tiers, Low Cost (under $100 - 30fps), Budget (under $250- 60fps), Midrange ($250-$400-90fps), Highend ($400&up - 120fps), (Frame Per Seconds - in games).

- Memory, 16gb is comfortable now, 8gb is minimum, if you have only 4gb, add another 4. Memory size doesn't make your pc faster, it depends on your memory consumption. Memory is like a work table, bigger table doesn't mean you can work more quickly, depends on how many stuff you working on it.

- Harddisk, get a Solid State Disk, is much faster than regular spinning harddrive. But regular hdd got more space for much cheaper. Its best to combine the best of the 2, usually people use SSD for their C (windows) drive and a big HDD for their D drive.

3. Look for the Phisical & Logical combinations, 6 physical * 2 logical means you get 12 threads in total. There are some cpu that only has 1 logical like the 6 threads i5 9600k which has 6 physical but only has 1 logical, so you'll get 6 threads.

[keavlar]

7 minutes ago, Enderman said:

Nope.

Look at 9700K vs 9900K.

The 9900K has hyperthreading and that allows it to outperform the 9700K in multithreaded tasks, because it essentially can do 16 things at the same time instead of 8.

Didn't knew that Intel Core i7-9700K @ 3.60GHz doesn't have logical cores. That why I assumed that they are the same in numbers.

[Enderman]

2 minutes ago, keavlar said:

Didn't knew that Intel Core i7-9700K @ 3.60GHz doesn't have logical cores. That why I assumed that they are the same in numbers.

Haha no, there's a reason the 9900K costs a ton more than the 9700K

[keavlar]

Just now, Enderman said:

Haha no, there's a reason the 9900K costs a ton more than the 9700K

XD  I didn't knew, never was kinda into it. 

Have 4790k , and that is all I care , until I will be looking for a new build for my pc. 

[SupaKomputa]

2 minutes ago, keavlar said:

Didn't knew that Intel Core i7-9700K @ 3.60GHz doesn't have logical cores. That why I assumed that they are the same in numbers.

So Intel can set the pricing better, i7 9700K is basically the same chip as 9900k but the multithreading is disabled.

[keavlar]

6 minutes ago, SupaKomputa said:

 

- Memory, 16gb is comfortable now, 8gb is minimum, if you have only 4gb, add another 4. Memory size doesn't make your pc faster, it depends on your memory consumption. Memory is like a work table, bigger table doesn't mean you can work more quickly, depends on how many stuff you working on it.

 

About that!

Can be 8 GB enough for browsing with more then 16 tabs open +  have working on https://www.sketchup.com/

With i7-8750H (laptop)

[SupaKomputa]

8gb is good enough, but if you wan't to do other stuff, you may want to exit the other one.

Sketchup is pretty low on memory usage. But it scales with the complexity of your model / scene.

You'll be amazed how a browser app can consume very high memory, around 300mb / tabs.

Your laptop CPU is pretty good actually, no need to worry about that for another 3-5 years.

For some serious work i suggest you match it up with a 16gb.

 

[keavlar]

1 hour ago, SupaKomputa said:

8gb is good enough, but if you wan't to do other stuff, you may want to exit the other one.

Sketchup is pretty low on memory usage. But it scales with the complexity of your model / scene.

You'll be amazed how a browser app can consume very high memory, around 300mb / tabs.

Your laptop CPU is pretty good actually, no need to worry about that for another 3-5 years.

For some serious work i suggest you match it up with a 16gb.

 

Thx mate