8 Threads Vs 6 cores

[AnTicXz]

So I'm going to upgrade to ryzen. If the single core performance is the same what would be better 6 cores or 8 threads 

[iBabySlapper]

Six cores is better than four with hyperthreading.

[Sprawlie]

that's not a straight forward questions:

 

8 "threads" could be a mix of physical and logical cores. For example, an i7-7700 will have 8 threads but 4 of those are physical cores and 4 of those are logical.

 

So it's not easy to answer your question, you have to understand what the breakdown between Logical and Physical thread/core count is. at the end of the day, just remember, Physical Cores > Logical cores 

 

 

[EunSoo]

Ask this question when it comes out. There will be plenty of guides, reviews and benchmarks that will be much more accurate than anything anyone can give you know.

 

Does the 6 core processor have 12 threads or only 6? If 6, I would still go for the 6 core

[BingoFishy]

1 minute ago, Sprawlie said:

that's not a straight forward questions:

 

8 "threads" could be a mix of physical and logical cores. For example, an i7-7700 will have 8 threads but 4 of those are physical cores and 4 of those are logical.

 

So it's not easy to answer your question, you have to understand what the breakdown between Logical and Physical thread/core count is. at the end of the day, just remember, Physical Cores > Logical cores 

 

 

He's aware of this. He's looking for a specific answer of "how much better," which we'll need Ryzen to come out for to find out.

[Enderman]

4 minutes ago, ibabyslapper said:

Six cores is better than four with hyperthreading.

Nope, threads perform almost identically to cores.

That's why in a recent LTT video a 2 core 4 thread i3 performed identically to a 4 core i5.

[Ensho]

Are there definitely going to be 6 core Ryzen cpus?  The latest article on Guru3D stated only the 8 core parts are going to launch on time and that the 4 core parts were being delayed by 4 months to work out bios bugs...and that there has been no mention of 6 core parts.

 

http://www.guru3d.com/news-story/amr-ryzen-new-speculation-on-prices-and-release.html

[dalekphalm]

2 minutes ago, CODboyX said:

So I'm going to upgrade to ryzen. If the single core performance is the same what would be better 6 cores or 8 threads 

You're not asking a clear question.

 

8 threads are the same as 8 cores. Unless they're not. If you have an 8-core CPU without hyperthreading/SMT, that has the same number of threads as a 4-core w/ hyperthreading/SMT.

 

Now, I assume you're actually comparing a 4c8t CPU to a 6c6t CPU. In that case, it depends on what you use it for. A full dedicated core (w/o SMT) will run the same speed as an equivalent thread in a CPU with the same architecture/clock rate, assuming it's just the one thread being used.

 

Once you start to introduce additional threads and tasks, it begins to stop scaling perfectly.

 

So, for example, if you're running a program that will utilize 6 threads, it will run faster on the 6c6t CPU over the 4c8t CPU. The reason why is because there's still the same hardware per core there. Hyperthreading/SMT doesn't magically give you more cores or free processing. What it does do, though, is allow unused hardware resources in a core to be utilized by another task.

[Ensho]

2 minutes ago, Enderman said:

Nope, threads perform almost identically to cores.

That's why in a recent LTT video a 2 core 4 thread i3 performed identically to a 4 core i5.

No it didn't.  Not one single review stated that.  Physical cores > Logical cores.

[Sprawlie]

4 minutes ago, BingoFishy said:

He's aware of this. He's looking for a specific answer of "how much better," which we'll need Ryzen to come out for to find out.

hence why it's impossible to answer based on the limited exchange of his question, but instead of just answering without merrit, I gave him reasoning why one would be better than the other.

 

at the end of the day, the simple math stll applies.

 

Physical cores > Logical cores.

 

a CPU with 4 cores is better than a CPU with 2 physical cores and 2 logical cores.

a CPU with 6 cores would be better in most cases than a CPU with 4 and 4 logical

 

But he didn't ask that. he asked is 6 cores better than 8 threads. To which we can only answer that it's an impossible question to answer because we don't know the make up of those 8 threads. I would prefer to have a 6 physical core CPU over a 4+4, but that wasn't what was stated in the question

 

it also failes to take into account power of those cores, since not all cores themselves are created equal. For example, if I were gaming, I would opt for the 4c+4ht CPU to take advantage of faster single core performance, than a 6 core CPU with lower clocks.

 

at the end of the day, the question itself is very vague and cannot be accurately answered without providing more context to the question. in absense of that context, i have attempted to provide the user sufficient information to be able to understand his own question better

 

 

[Enderman]

1 minute ago, Ensho said:

No it didn't.  Not one single review stated that.  Physical cores > Logical cores.

Go watch the video again, it's almost identical.

 

[TheRandomness]

2 minutes ago, Enderman said:

Nope, threads perform almost identically to cores.

That's why in a recent LTT video a 2 core 4 thread i3 performed identically to a 4 core i5.

Well, it depends on the workload. Because no way in hell can you replace an actual core with a thread.

[Enderman]

1 minute ago, TheRandomness said:

Well, it depends on the workload. Because no way in hell can you replace an actual core with a thread.

Plz go watch the video posted above.

It is very close.

[ARikozuM]

6 minutes ago, Enderman said:

Nope, threads perform almost identically to cores.

That's why in a recent LTT video a 2 core 4 thread i3 performed identically to a 4 core i5.

In a video that used 4K to test performance...

[dalekphalm]

3 minutes ago, Enderman said:

Nope, threads perform almost identically to cores.

That's why in a recent LTT video a 2 core 4 thread i3 performed identically to a 4 core i5.

Link? Historically, logical threads have never performed quite as well as physical cores. In some tasks, yes. But those tasks weren't utilizing the full resources of that core.

 

2 minutes ago, Enderman said:

Go watch the video again, it's almost identical.

 

I'll have to rewatch that to see what you're talking about. I do recall there being tons of issues with that particular review/video though, so I'm not really sure it's a reliable metric. In any case, I'll revisit after I've rewatched it.

[EunSoo]

2 minutes ago, Enderman said:

Go watch the video again, it's almost identical.

 

I can't watch the vid rn but I think that it was compared to a 2500k, not a 6600k or 7600k

[Enderman]

3 minutes ago, SCGazelle said:

I can't watch the vid rn but I think that it was compared to a 2500k, not a 6600k or 7600k

It was a 7400.

Same architecture.

[Mr.Meerkat]

3 minutes ago, Enderman said:

Plz go watch the video posted above.

It is very close.

Plz, the i3 is running at a higher clock speed...3GHz stock and 3.5GHz boost vs 4.2GHz stock, I wonder...

Also, did you know that the 7350K is more expensive than a 7400? 

[EunSoo]

3 minutes ago, Enderman said:

It was a 7400.

Same architecture.

u sure? i don't think that th 7400 is that much worse than a 6600k. I agree that the 7350k is a very good option but i'm just saying that its not exactly the same as an i5, at least in multicore. That single core tho

[Mr.Meerkat]

3 minutes ago, SCGazelle said:

u sure? i don't think that th 7400 is that much worse than a 6600k. I agree that the 7350k is a very good option but i'm just saying that its not exactly the same as an i5.

No, the 7400 is slower than the 7350K...but the i5 is cheaper so...it makes sense?  

http://cpu.userbenchmark.com/Compare/Intel-Core-i5-7400-vs-Intel-Core-i3-7350K/3886vs3889

 

edit: Also when all 4 threads are utilised, the i3 has a 1.2GHz~ advantage over the i5 so there's a reason why the i5 is slower...

[ARikozuM]

2 minutes ago, Enderman said:

It was a 7400.

Same architecture.

It was the 7700K downclocked to "be" an i5-7400 as he says at 3:00.

 

The 7400 is also slower than the i3 when it comes to frequency.

 

 

[EunSoo]

3 minutes ago, Mr.Meerkat said:

No, the 7400 is slower than the 7350K...but the i5 is cheaper so...it makes sense?  

http://cpu.userbenchmark.com/Compare/Intel-Core-i5-7400-vs-Intel-Core-i3-7350K/3886vs3889

ok. Especially when you have to buy a z270 board along with it.

[ARikozuM]

23 minutes ago, CODboyX said:

So I'm going to upgrade to ryzen. If the single core performance is the same what would be better 6 cores or 8 threads 

Whichever the faster chip is.

[Ensho]

16 minutes ago, Enderman said:

Go watch the video again, it's almost identical.

 

Oh, I thought you were talking about the i5 7600k...which is a 4 core part.

[Mr.Meerkat]

1 minute ago, Ensho said:

Oh, I thought you were talking about the i5 7600k...which is a 4 core part.

He should have been using the i5 7600K for his argument about HT threads, obviously the CPU with a 1.2GHz higher base clock advantage is going to make up the considerable difference between a thread an a core