PC Building

[nec_v20]

For those of you wondering if they should get a 7000 series vs a 5000 series AMD CPU, let me show you the following that may make your choice a bit easier.

Let's face it, the Tech Media/YouTubers have shown themselves to be as useful as a chocolate teapot when it comes to reviewing Ryzen from the 3rd Gen onwards (a tradition they have not broken with the 5th Gen).

Going from 7nm to 5nm with my Ryzen 5950X and Ryzen 7950X I get the following results

At the same performance level (maximum CineBench R23 score for my 5950X) I get the following:

1) CPU voltage
5950X 1.3 Volts
7950X 0.83 Volts
For the same performance vs 7nm the 5nm uses 63% of the Voltage (or rather the 5950X uses 56.6% more Voltage)

2) CPU Clockspeed
5950X 4.675 GHz
7950X 4.115 GHz
For the same performance vs 7nm the 5nm needs 89.2% of the clockspeed (or rather the 5950X needs 12.7% more Clockspeed)

3) CPU Wattage
5950X 180 Watts
7950X 54 Watts
For the same performance vs 7nm the 5nm uses 30% of the Power (or rather the 5950X needs 333% more Power).

Now I am going to stay within the 7950X performance numbers but going from the maximum CineBench R23 score I got for the 5950X to the maximum score I can achieve with 7950X at the same maximum power level in terms of Wattage of the 5950X maxed out (around 180 Watts) I get the following:

1) CPU Voltage
7950X at 4.115 GHz 0.83 Volts
7950X at 5.35 GHz 1.2 Volts
For the performance increase it needs 44.5% more voltage

2) CPU clockspeed
7950X at 4.115 GHz
7950X at 5.35 GHz
For the performance increase it needs 29% more clockspeed

3) CPU Wattage
7950X at 4.115 GHz 54 Watts
7950X at 5.35 GHz 177 Watts
For the performance increase it uses 321% more power

Difference in CBR23 score
7950X at 4.115 GHz 31,108
7950X at 5.35 GHz 40,210
The score increase is 29.2%

The bottom line here is that for 29% more clockspeed I am getting a score increase of 29.2%

I think it goes without saying that I am nowhere near 95 degrees Celsius when I am maxed out and fun fact, my temps are lower and performance a lot higher than what JayzTwoCents managed to achieve when he delidded his 7950X and decided to go direct die - what a scrub.

As far as my own personal use case is concerned, I worked out that going to the 7950X from my 5950X means that the 7950X hardware upgrade (CPU, Motherboard and RAM) will have paid for itself in terms of savings in electricity costs (I have a SeaSonic Prime Titanium 1000W PSU) within one and a half years.

[Weber462]

Nice write up!  Thanks

[johnnyenglish]

That is great info!!

Can I use this on a vídeo review of 7950x and give you credit for?

Im a "micro"tuber so... its not going to give you fame or glory but the info is quite good to be shown.

Cheers 

[nec_v20]

Of course you can, and if you wish, I wrote a revision to my guide on how to optimally configure any 3rd, 4th and 5th Gen Ryzen CPU on any motherboard in about five to ten minutes (exception being the 5800X3D because AMD nerfed it).

I originally wrote the guide here on this forum over three years ago. I have a friend Paul who is dyslexic and he had a bad time reading the guide and so I set about revising and condensing the guide according to the principle WWPR (What Would Paul Read) and I put it on reddit.

The original guide works the same on all the generations of Ryzen from the 3000 series to the 7000 series, except of course you don't need as much voltage for the 7000 series as you do for the other two (maximum safe voltage for the 5nm node7000 series is 1.2 Volts according to TSMC).

I posted the added info for the 7000 series in another guide on reddit. I will link to both below, so that you can check my numbers.

After all there is no point in telling you my numbers if I don't tell you how I got there.

The main guide for configuring any Ryzen:

https://www.reddit.com/r/ryzen/comments/tntrif/definitive_guide_to_configuring_3rd4th_gen_ryzen/

The updates for the 7000 series:

https://www.reddit.com/r/ryzen/comments/xr7iik/definitive_guide_to_configuring_all_ryzen_7000/

[Axxemann]

So, as a gamer who only very recently made the switch to AM4 from AM3+ (when Halo: Infinite and War Thunder started crashing to desktop mid game, it was time to upgrade from my FX-8120) are these 3rd/4th gen Ryzen optimizations going to do me any good? I'm still learning Zen3 and I skipped right past the previous generations. Budgetary constraints are going to keep me out of Zen4, and I might get on AM5 around Zen5 I think.

[nec_v20]

One thing to know about 3rd, 4th and 5th Gen Ryzen is that AMD thought it would be a great idea to bastardize the entire configuration to optimize single core performance so that they could put a bigger number up with regard to a boost clockspeed.

The thing is that the boost clockspeed only counts for a single core (this is why I call it a "Single Core Boast Speed") and with multiple cores engaged it punts in way too much voltage for way too little performance.

So using my guide you will get a far higher multi-core performance (good for games, because very few, if any, games are single core any more) at far lower temps.

[ajlueke]

"maximum safe voltage for the 5nm node7000 series is 1.2 Volts according to TSMC"

At what amperage?

[nec_v20]

I didn't look for that information, I was interested in the voltage and it was a friend of mine (who was also interested) who found the info.

On the other hand the point of diminishing returns starts at 1.175 Volts.

If you want to find out the amperage then you will need to look for that information yourself.

If you find it then I'd be interested in the results.

[ajlueke]

The results are pretty interesting.  As it seems the default TDP is way past the point of diminishing returns, and you can get most of the performance benefit at much lower wattage/amperage (or the 95C die temp).  

I'll see if I can find the TMSC 5nm white paper.  I imagine they would list amperage constraints as well.

The cost data is interesting as well.  Assuming I run the 7950X at the same performance level as the 5950X, I would be saving (180W-54W) = 126W or 0.126kW/hr.  Run 24 hrs a day full bore would be 3 kW/hr.  Average electricity price in the USA is $0.166 per kW/hr so that would be $0.5 per day, or $182.5 a year.   With those savings it would take over three years to earn back the price of the 7950X by itself.

That is also assuming the system is run full bore continuously.  In my scenario, where I have an X470 based motherboard, the X670 would draw more electricity any time the system is relatively idle (5W TDP vs 7+7W TDP).  Which would lengthen the time to parity even further.  Assuming about $200 for RAM and another $200 for a motherboard, it would take me well over 5 years to pay back the difference.  Factoring in the idle time vs actually full operation and I'm probably looking at well over 6/7 years.  So yeah, I'm not sure if the jump would really be worth it from a cost perspective, at least not in my case.  

[nec_v20]

My CPU temp  running CineBench R23 at 5.35 GHz all core delta (CPU temp minus ambient) is around 50 degrees Celsius and the wattage is 177 Watts, and my CB R23 score is 40,210 with an Arctic Liquid Freezer II using the offset mount. As opposed to JayzTwoCents who had a delta of 55 degrees Celsius with his delidded 7950X and a lower CB R23 score.

I am working on a massive post at the moment which will show you where the savings come from.

I live in Europe.

[ajlueke]

I'll keep an eye out for it.

I assumed as much.  The electricity prices in Europe are more than double those in the States currently. 

[nec_v20]

The price for electricity here in the UK where I live has gone through the roof. The change from the 5950X to the 7950X is saving me between £1.50 - £1.75 a day.

This is why I am so elated with the 7950X system.

I have been an enthusiast for the chiplet based Ryzen CPUs since the 3950X I had.

With the 7950X I have crossed the line into being a FanBoi in fact I would go so far as to say I am an AMDeboo 😂

[eebiii]

Great Info! Thank you