We’ve had a lot of different CPU tests here in recent weeks AMD Ryzen 9 9950X. It’s a new 16-core processor from AMD with the Zen 5 architecture. A lot of tests are about scaling performance with changing power consumption, and it’s no different here. The test was a benchmark Cinebench R23 in its multi-threaded version, and the author here tried to set the PPT consumption (i.e., the maximum consumption) from 40 W to an unrestricted state, which resulted in a consumption of 309 W. This is definitely not little, but on the other hand, the processor repaid it with very high performance . And how did it all turn out?
Just like last time, there will be two charts today. On the first one you can see the performance depending on the consumption. The relationship is not linear, and as you can see, with further growth in consumption (as you go further to the right on the graph), performance gradually stops growing (the orange line does not go up much anymore). On the other hand, on the left side of the graph, you can see that if you go too low with the consumption (to 40W), the orange line representing the power drops significantly. That is it’s not good to go too high with the consumption (the orange line doesn’t grow much anymore), but not too low either (the orange line drops terribly fast). We see a fairly rapid growth here between 60 and 160 W, then the orange line grows slowly.
The blue line on the graph shows the number of points per watt. The processor is thus most efficient at 60W PPT, when it has 400 points per watt. Then it drops and, for example, when working without consumption restrictions, this ratio is only 155 points per watt. That’s not even 40% efficiency against the maximum. Let’s also note here that in the default state the processor is set to 230W PPT (which brings 200 points per watt). So it can be seen that with the reduction of TDP and PPT, the processor will run slower, but more efficiently. However, as soon as you fall below 60 W, the efficiency starts to decrease. But you certainly don’t buy a 16-core processor to run it at 60 W. But what is the ideal?
Here it is again, from the opposite view. It can be seen how the consumption (orange line) gradually grows steeper and steeper. The more power you want, the faster the consumption will grow. The blue line shows the efficiency, i.e. the number of watts per 1000 points in the benchmark. Logically, it is the lowest at 60 W (we have already seen this in the previous graph), where it is only 2.5 W. But if you look at the shape of this curve, you can see that it grows more or less linearly up to 160 W PPT, but then it picks up significantly steeper direction. This could also be seen in the first graph, where we saw the power grow quite quickly up to 160 W, then it was quite slow. 60W consumption (26% of the maximum) is the most efficient, but you sacrifice 48% of the performance, which is a lot. Probably the ideal place where we have the best ratio between performance and efficiency (not consumption, but efficiency) is the 160 W. Although the processor there is not the most efficient, it is still significantly better than the standard 230 W PPT. It has 30% less consumption, but only 8% lower performance.
A comparison with Intel should not be missing either. If we take unlimited processors (or rather unlimited 309W AMD and 320W Intel on Extreme profile), then AMD wins over 14900KS by 12.5%. If we look at the 253W versions, AMD has a nice 13.6% lead.
We can also look at the 320W Intel and what consumption AMD needs for that. According to the graph, it’s somewhere between 160 and 180 W, it looks like somewhere around 165 W. That’s basically half the consumption (-48%) compared to Intel. If we were to look at the 253W Intel Core i9-14900KS, the AMD Ryzen 9 9950X only needs about 150-155 W (-40%) for the same performance.
Source: www.svethardware.cz
