Discussion Zen 5 Speculation (EPYC Turin and Strix Point/Granite Ridge - Ryzen 9000)

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FlameTail

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Dec 15, 2021
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Then the whole discussion side tracked into a sub-discussion of whether 5.7 or 5.85 Ghz was correct to use. This despite that it only leads to 2,6% difference, which is too little to matter for the original topic being discussed as I understand it.
If we can't come to an agreement, let's take the average of 5.7 and 5.85, which is 5.75! Is everybody happy?
 

Thunder 57

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Aug 19, 2007
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Timorous

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Then the whole discussion side tracked into a sub-discussion of whether 5.7 or 5.85 Ghz was correct to use. This despite that it only leads to 2,6% difference, which is too little to matter for the original topic being discussed as I understand it.

The correct numbers are clearly the measured ones from the review in question. It may not make much difference or change the conclusion but if you have accurate data to use then use it rather than fudging it.
 
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Tuna-Fish

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Mar 4, 2011
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Holy image spam. Care to at least summerize what is being said?

Zen2 and Zen3 are both "6 wide", but 6 "what" wide differs. Zen6 is 6 uop wide, that is, in the frontend the incoming x86 ops get split into uops and at most 6 of them are submitted forward per clock. Zen3 is 6 macro-op wide, where each x86 op generally converts into one macro-op.

This is mostly significant for load-alu instructions, like "add rax, [rdx]", where Zen2 needs 2 uops per insn while Zen3 only needs one Mop per insn.
 

Fjodor2001

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Feb 6, 2010
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The correct numbers are clearly the measured ones from the review in question. It may not make much difference or change the conclusion but if you have accurate data to use then use it rather than fudging it.
I agree it's important for correctness sake to use the right numbers. However in this case I'm not sure which are the correct ones, and there seems to be differences of opinion about that. But it seems like all agree on that the difference is also so small at 2,6% that it should not affect the conclusion much.

But let's say we use the numbers you prefer, then what is the conclusion from the original topic? I.e. the relationship between the SPECint and Cinebench measurements?
 
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Timorous

Golden Member
Oct 27, 2008
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I agree it's important for correctness sake to use the right numbers. However in this case I'm not sure which are the correct ones, and there seems to be differences of opinion about that. But it seems like all agree on that the difference is also so small at 2,6% that it should not affect the conclusion much.

But let's say we use the numbers you prefer, then what is the conclusion from the original topic? I.e. the relationship between the SPECint and Cinebench measurements?

It is not really a difference of opinion. One is using the number measured by the reviewer for a single threaded workload, the other is using fmax.

Clearly the measured figure is the correct one to use when you are using that reviews single core Specint score and normalising to get a relative IPC delta.
 

Fjodor2001

Diamond Member
Feb 6, 2010
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It is not really a difference of opinion. One is using the number measured by the reviewer for a single threaded workload, the other is using fmax.

Clearly the measured figure is the correct one to use when you are using that reviews single core Specint score and normalising to get a relative IPC delta.
Ok, let’s go for that then. So using the numbers you said are the correct ones, what’s the conclusion regarding the relationship between the SPECint and Cinebench measurements?
 
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tamz_msc

Diamond Member
Jan 5, 2017
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It is not really a difference of opinion. One is using the number measured by the reviewer for a single threaded workload, the other is using fmax.

Clearly the measured figure is the correct one to use when you are using that reviews single core Specint score and normalising to get a relative IPC delta.
Just because it has been measured doesn't mean that it sustained that frequency through the benchmark run.

It is a moot point, because a benchmark usually takes orders of magnitude longer to run compared to the total time for which fMax is observed during that time.
 

tamz_msc

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Jan 5, 2017
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Ok, let’s go for that then. So using the numbers you said are the correct ones, what’s the conclusion regarding the relationship between the SPECint and Cinebench measurements?
Conclusion is that if the PPC improvement in SPECint is, for argument's sake, 10%, it is very unlikely that the PPC improvement in Cinebench wouldn't be in the same ballpark.

Unless the CPU design is out-of-whack where it breaks the benchmark itself, 40% core-for-core improvement in SPECint will not likely result in an 18% improvement in Cinebench.
 

Hitman928

Diamond Member
Apr 15, 2012
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Ok, let’s go for that then. So using the numbers you said are the correct ones, what’s the conclusion regarding the relationship between the SPECint and Cinebench measurements?

First, my original reply on this subject was simply because one of the numbers looked suspiciously different than the generally accepted increase for SPECint. So I asked how it was calculated which led to a whole series of deflection and defensive posts and exposed a rather casual attitude toward data accuracy which makes me not trust any of the numbers, tbh (which is the more important point than exactly how much it changes the results). However, even if we take the numbers at face value, let's just look at how the two tests matchup.

Cinebench R23SPECint 2017
Zen+ -> Zen 219.3%16.8%
Zen 2 -> Zen 314.9%19.7%
Zen 3 -> Zen 45.1%5.6%

If we take the SPECint numbers as the baseline, here is the "error" margin in how well Cinebench represents IPC gain in SPECint.

Cinebench IPC increase relative to SPECint 2017 IPC increase
Zen+ -> Zen 214.9%
Zen 2 -> Zen 3-24.4%
Zen 3 -> Zen 4-8.93%


If we assume that the 40% SPECint increase is true for Zen 5 and use this possible range of values, here are the predicted Cinebench IPC numbers.

Zen 4 Cinebench (ST) IPC prediction based upon previous Cinebench to SPECint IPC error calculation
Zen+ -> Zen 245.96%
Zen 2 -> Zen 330.24%
Zen 3 -> Zen 436.43%

So, it seems that given the presented numbers (which have questionable accuracy for at least one entry), Cinebench is not a great predictor for SPECint IPC increases. There will be some correlation, obviously because you are improving the CPU which will effect both results, but that is very different than saying one is an accurate predictor of the other.

Edit:

If you use the corrected Zen3 -> Zen 4 SPECint 2017 number (7.8%), you get the following:

Cinebench IPC increase relative to SPECint 2017 IPC increase
Zen+ -> Zen 214.9%
Zen 2 -> Zen 3-24.4%
Zen 3 -> Zen 4-34.6%

Zen 5 Cinebench (ST) IPC prediction based upon previous Cinebench to SPECint IPC error calculation
Zen+ -> Zen 245.96%
Zen 2 -> Zen 330.24%
Zen 3 -> Zen 426.16%

So, as you can see, even though the absolute number only changes from 5.6% to 7.8%, the error margin actually grows significantly. So yes, getting the right number here does make a big difference in terms of the subject at hand. If the argument is that Anandtech's sample might not have sustained the 5.75 GHz frequency, then that only makes the error margin worse as the frequency will drop and the SPECint IPC number will go up, as will the error margin.

Edit: Fixed tables from Cinebench ST score to IPC prediction. Also, as I stated in reply to the original tweet, the scores shown in the tweet are literally just a random poster's speculation from a Chinese forum, so none of this actually matters in regards to Zen 5 performance.
 
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tamz_msc

Diamond Member
Jan 5, 2017
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First, my original reply on this subject was simply because one of the numbers looked suspiciously different than the generally accepted increase for SPECint. So I asked how it was calculated which led to a whole series of deflection and defensive posts and exposed a rather casual attitude toward data accuracy which makes me not trust any of the numbers, tbh (which is the more important point than exactly how much it changes the results). However, even if we take the numbers at face value, let's just look at how the two tests matchup.

Cinebench R23SPECint 2017
Zen+ -> Zen 219.3%16.8%
Zen 2 -> Zen 314.9%19.7%
Zen 3 -> Zen 45.1%5.6%

If we take the SPECint numbers as the baseline, here is the "error" margin in how well Cinebench represents IPC gain in SPECint.

Cinebench IPC increase relative to SPECint 2017 IPC increase
Zen+ -> Zen 214.9%
Zen 2 -> Zen 3-24.4%
Zen 3 -> Zen 4-8.93%


If we assume that the 40% SPECint increase is true for Zen 5 and use this possible range of values, here are the predicted Cinebench IPC numbers.

Zen 4 Cinebench (ST) IPC prediction based upon previous Cinebench to SPECint IPC error calculation
Zen+ -> Zen 245.96%
Zen 2 -> Zen 330.24%
Zen 3 -> Zen 436.43%

So, it seems that given the presented numbers (which have questionable accuracy for at least one entry), Cinebench is not a great predictor for SPECint IPC increases. There will be some correlation, obviously because you are improving the CPU which will effect both results, but that is very different than saying one is an accurate predictor of the other.

Edit:

If you use the corrected Zen3 -> Zen 4 SPECint 2017 number (7.8%), you get the following:

Cinebench IPC increase relative to SPECint 2017 IPC increase
Zen+ -> Zen 214.9%
Zen 2 -> Zen 3-24.4%
Zen 3 -> Zen 4-34.6%

Zen 5 Cinebench (ST) IPC prediction based upon previous Cinebench to SPECint IPC error calculation
Zen+ -> Zen 245.96%
Zen 2 -> Zen 330.24%
Zen 3 -> Zen 426.16%

So, as you can see, even though the absolute number only changes from 5.6% to 7.8%, the error margin actually grows significantly. So yes, getting the right number here does make a big difference in terms of the subject at hand. If the argument is that Anandtech's sample might not have sustained the 5.75 GHz frequency, then that only makes the error margin worse as the frequency will drop and the SPECint IPC number will go up, as will the error margin.

Edit: Fixed tables from Cinebench ST score to IPC prediction. Also, as I stated in reply to the original tweet, the scores shown in the tweet are literally just a random poster's speculation from a Chinese forum, so none of this actually matters in regards to Zen 5 performance.
Wow, somebody missed their basic statistics class in school. Instead of meandering with silly mafs you could have simply calculated the correlation coefficient.

Here, I did it for ya -

With 5.6% change it is 0.940594.
With 7.8% change, it is 0.926675.

Across the entire data set - for the three cases each for Intel and AMD.
 

Hitman928

Diamond Member
Apr 15, 2012
5,339
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Wow, somebody missed their basic statistics class in school. Instead of meandering with silly mafs you could have simply calculated the correlation coefficient.

Here, I did it for ya -

With 5.6% change it is 0.940594.
With 7.8% change, it is 0.926675.

Across the entire data set - for the three cases each for Intel and AMD.

I know how to calculate the correlation coefficient but that doesn't tell us what you seem to think it does. You can't use strong correlation to mean small variance between data sets (e.g., that the trend of one can be replaced by the value of the other).

To visualize this, take the following data sets:



They have perfect correlation (coefficient = 1). However, one does not represent the growth of the other in absolute terms and the data sets diverge significantly over their range (they just do so linearly which is why they have a correlation coefficient of 1). What you are claiming cannot be supported by calculating the correlation coefficient, especially when the data set is ridiculously small which makes the coefficient basically meaningless. I thought showing the projected Cinebench IPC numbers based upon past generations would make that obvious, but I guess not. Maybe if we look at it from already known values.

Let's take the first two generations calculated and pretend like Zen 2 hadn't been tested with SPECint yet. If Cinebench is a good representative of SPECint IPC increases, then we should be able to predict Zen 2 SPECint IPC based upon the Zen+ to Zen2 Cinebench numbers.


Cinebench R23SPECint 2017
Zen+ -> Zen 219.3%16.8%
Zen 2 -> Zen 314.9%12.97% predicted / 19.7% actual


But the actual value of Zen 2 -> Zen 3 IPC increase was 19.7%. That means the predicted value was off by 34.2% (absolute). That's a terrible error percentage, it was more than 1/3 off from the actual value.

Feel free to continue to believe how you want, but the numbers show that Cinebench is a terrible predictor of SPECint IPC.
 
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StefanR5R

Elite Member
Dec 10, 2016
5,532
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136
Wow, somebody [...]
[...] has never observed a set of different computing algorithms running on a set of different microarchitectures.

(PS, actually even different implementations of one and the same microarchitecture show different performance scaling with power, thermals, memory subsystem etc. for different algorithms. PPS, envisioning a correlation between INT and FP takes the cake though.)
 
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tamz_msc

Diamond Member
Jan 5, 2017
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I know how to calculate the correlation coefficient but that doesn't tell us what you seem to think it does. You can't use strong correlation to mean small variance between data sets (e.g., that the trend of one can be replaced by the value of the other).

To visualize this, take the following data sets:

View attachment 97350

They have perfect correlation (coefficient = 1). However, one does not represent the growth of the other and the data sets diverge significantly over their range (they just do so linearly which is why they have a correlation coefficient of 1). What you are claiming cannot be supported by calculating the correlation coefficient, especially when the data set is ridiculously small. I thought showing the projected Cinebench IPC numbers based upon past generations would make that obvious, but I guess not. Maybe if we look at it from already known values.

Let's take the first two generations calculated and pretend like Zen 2 hadn't been tested with SPECint yet. If Cinebench is a good representative of SPECint IPC increases, then we should be able to predict Zen 2 SPECint IPC based upon the Zen+ to Zen2 Cinebench numbers.


Cinebench R23SPECint 2017
Zen+ -> Zen 219.3%16.8%
Zen 2 -> Zen 314.9%12.97% predicted / 19.7% actual


But the actual value of Zen 2 -> Zen 3 IPC increase was 19.7%. That means the predicted value was off by 34.2% (absolute). That's a terrible error percentage, it was more than 1/3 off from the actual value.

Feel free to continue to believe how you want, but the numbers show that Cinebench is a terrible predictor of SPECint IPC.
Correlation coefficient is NOT used for prediction.

Correlation coefficient is used to accept or reject the null hypothesis.

In this case, the p-value is roughly 0.025, which is less than 0.05 for 95% confidence interval.

So you have to reject the null hypothesis.
 

tamz_msc

Diamond Member
Jan 5, 2017
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[...] has never observed a set of different computing algorithms running on a set of different microarchitectures.

(PS, actually even different implementations of one and the same microarchitecture show different performance scaling with power, thermals, memory subsystem etc. for different algorithms. PPS, envisioning a correlation between INT and FP takes the cake though.)
This discussion has nothing to do with CPU architectures or benchmarks.
 

Hitman928

Diamond Member
Apr 15, 2012
5,339
8,107
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Correlation coefficient is NOT used for prediction.

Exactly. . .

Correlation coefficient is used to accept or reject the null hypothesis.

The p-value is used for this, not the correlation coefficient.

In this case, the p-value is roughly 0.025, which is less than 0.05 for 95% confidence interval.

So you have to reject the null hypothesis.

Sure, but the entire analysis is in question due to the tiny sample size.

At this point, I don't even know what your argument is related your original post on the subject:

Doesn't look too good for "40% core-for-core faster than Zen 4 in SPECint 2017" claims, if [Cinebench numbers are] true.

I'm just going to leave it at this, like I said earlier, believe what you want, others can make up their own minds as well. We'll see what Zen 5 really is soon enough.
 
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tamz_msc

Diamond Member
Jan 5, 2017
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Sure, but the entire analysis is question due to the tiny sample size.
So use the individual scores, across each of SPECint and SPECfp, throw in the individual scores of Geekbench, add every benchmark that spits out a number that implies the higher the better, get the dataset size to acceptable standards for the analysis, and you will still find that what I showed remains unchanged across CPU architectures.
 

DrMrLordX

Lifer
Apr 27, 2000
21,657
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This discussion has nothing to do with CPU architectures or benchmarks.

If that's the case, then unless it's a leg of some larger argument (by this point, that doesn't seem to be true), it might be best to drop it and wait for actual data on Zen5.

Feel free to continue to believe how you want, but the numbers show that Cinebench is a terrible predictor of SPECint IPC.

. . . which is to be expected. Why would an fp benchmark track with integer performance or vice versa across multiple generations of CPUs?
 

Schmide

Diamond Member
Mar 7, 2002
5,587
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And the AVX instructions in that graph are mostly scalar additions and multiplications. Very little vector instructions.

Everything in avx is vector, even when it isn't. (below) A scalar operation would just involve a broadcast (putting the same value into all elements of the vector) then a vector operation.

All processing happens in the same area. The upper elements are just ignored in lesser operations.

If you do a simple

add exx, exx

it is the same as a

vpaddd ymm, ymm, ymm

(with the caveat that 3 operands are allowed in the avx2 operation)

The above is why mixing vector levels (ex sse and avx) often incurs a penalties as the upper values of the register need to be preserved.
 
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Fjodor2001

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Feb 6, 2010
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Only 43 days left until the AMD keynote at Computex on June 3 and still not any solid leak. I wonder if we’ll get any credible and precise performance numbers or pricing info before that, or if AMD will manage too keep everything secret until we hear it from Lisa Su directly. Any opinions, based on e.g. past track record?
 
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Goop_reformed

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Sep 23, 2023
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Only 43 days left until the AMD keynote at Computex on June 3 and still not any solid leak. I wonder if we’ll get any credible and precise performance numbers or pricing info before that, or if AMD will manage too keep everything secret until we hear it from Lisa Su directly. Any opinions, based on e.g. past track record?
My daughter's friend's uncle's newphew said Zen 5 > Arrowlake by a good chunk
 
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