Average CPU power draw
With the little (E) cores turned off, the Core i5-13400(F) becomes a 6-core processor with 12 threads in the same way that the older Core i5-12400(F) is. This intergenerational comparison is also a side product of tests main goal of which is to show the impact of E cores not only on computational and gaming performance, but also on operational characteristics. The biggest differences occur in the situations that mainstream PCs run into most often.
The level of benefit of Intel processors’ E cores with the big.LITTLE concept is a subject of frequent debate and controversy. In the Raptor Lake generation, small cores concern even the lowest models of the Core i5 class, which compared to their predecessor Core i5-12400(F) achieve significantly higher computational performance precisely because of the fact that they already have one cluster with E cores active. Core i5-13400F is no longer “only” a 6-core processors, but a 10-core one. However, the basis in the form of six P cores is the same as in Alder Lake. In the case of some variants (stepping C0), as you already know, an identical die with native 8 P and 8 E cores is even used. Others (Core i5-13400/F, stepping B0) are based on a larger die, which have 8 more E cores. We have already published a more detailed analysis of this. We will now focus on two other things:
- How E cores affect the Core i5-13400(F)’s computational (and “gaming”) performance and operating characteristics
- What is the practical difference of the Core i5-13400(F) versus the Core i5-12400(F), as long as there are only 6 P cores active in 12 threads – i.e. the same composition across generations. For this analysis, we will also make use of test results of the Core i5-12400 in different steppings (C0 and H0), where H0 is a variant with the little die that does not physically contain E cores (it only has 6 P cores) and C0 is based on the bigger, 16-core die. Just as a reminder. For details, see the article The same and yet different. Intel Core i5-12400 duel (H0 vs. C0)
Consider the tests in this article as just a sort of “baseline”, to be followed up later by going through the full gaming tests you’re used to from the standard CPU tests. For now, we will focus only on a selection of those tests in which, in addition to processor speed, we also monitor temperature, achieved clock speeds and power draw. The latter is measured with current clamps directly on the power cables. Thus, these are not distorted measurements by the rest of the components in the build, but only the net CPU power draw, which is only slightly affected by some power inefficiency of the VRM. However, we always use significantly over-dimensioned motherboards so that these external distortions are negligible, and especially for each processor (and across platforms) to a comparable degree.
What components we use, how we methodically approach the measurements of individual electrical and non-electrical quantities can be found in this chapter of this article and in the chapters that follow it.
Test results – 6+4 vs. 6 cores…
All charts with results can be found in Chapters 2 to 7, from which we draw conclusions in the following text.
To the first point, the comparison of the Core i5-13400(F) features in the complete configuration (i.e. with 6 P and 4 E cores) and in the configuration with only 6 P cores. The multi-threaded performance difference is very significant, up to 27% with active E cores with a 20% increase in power draw. If we convert this into efficiency, or a kind of efficiency ratio (ratio of computing power per unit of power draw), it is higher as long as E cores are used. Naturally, this comes at the cost of an increase in power draw, but it doesn’t drive the processor into inefficiency, on the contrary.So when Intel refers to E cores as “efficient” cores, everything agrees.
When it comes to gaming performance in the three titles tested (F1 2020, Shadow of the Tomb Raider and Total War Saga: Troy), the activity of the E cores doesn’t have much of an impact. In F1 2020 and TWST, the results are virtually identical and the biggest difference is in SOTTR. The difference in average fps is again negligible, but the drop in minimum fps after turning off E cores is already 10%. The latter can be attributed to the fact that a task that runs on a fully enabled processor on little cores and doesn’t need high performance, now reduces performance on P cores by leaps and bounds. We will release a more comprehensive impact of E cores on Core i5-13400F gaming performance later, as we announced. This is just sort of the first shot, from which the power draw analysis is most attractive.
The difference in power draw is always greater than the difference in gaming performance. The latter is minimal (around 1–2% on average), as mentioned above. However, without E cores, the processor is always more efficient and its power draw is at least 6% lower in some games (Shadow of the Tomb Raider), or even up to 16% lower in F1 2020.
And now to the really dramatic differences. Without E cores, the power draw of the Core i5-13400(F) is as much as 10 times higher. Yes, 10 times. Instead of a very pleasant 1.9 W, it’s up to the level of 17.8 W – between Core i5-12400 stepping C0 and Core i5-12400 stepping H0. This is probably because the operating system overhead can no longer run on low-power E cores and P cores require more aggressive power supply, and the whole operation is already quite inefficient compared to an optimal state.
Weaker efficiency is also the case for single-threaded performance, where power draw without E cores is significantly higher for the same reasons, and even at lower computational performance.If only P cores are enabled, the processor does not hold the multiplier of 46 on the key cores so steadily, but here and there during the test it drops to 41 (i.e. to the level of all-core boost), at which point it loses time. Minimally, but still, and we can conclude that shutting down the E cores has a negative impact even for running single-threaded tasks. This is both in terms of computing performance and in terms of power efficiency, which is almost half of it with only P cores.
… 6 vs. 6 cores (Raptor vs. Alder Lake)
And how does it compare between generations if the Ci5-13400F processor is limited to 6 P cores? Computing and gaming performance is always a bit higher for Raptor Lake, equivalent to higher clock speeds. At all-core boost and in games it’s 100 MHz and in single-core it’s 250 MHz on average (in favor of the Ci5-13400/F). In a multi-threaded load, the increase is 3%, single-threaded up to 5%.
The power draw of the Core i5-13400F on 6 P cores is virtually identical to the Core i5-12400(F) stepping H0 under high load (Cinebench R23). And in fact the efficiency as well, the differences in computational performance are minimal.
Efficiency in games is also similar with exceptions (SOTTR, where the Core i5-13400/F is a significantly more efficient processor). That is, if you compare a Core i5-13400(F), regardless of stepping (B0/C0), to a Core i5-12400(F) stepping H0 (i.e. one with a little die that only has 6 P cores on the PCB). The power draw of stepping C0 (with the Ci5-12400/F) is higher, and as the load decreases, its efficiency decreases compared not only to stepping H0, but also to all Core i5-13400Fs.
The difference while idle (1.9 vs. 25.5 W) is truly abysmal. If the E cores work really well somewhere with respect to efficiency, it is at minimum load. In this respect, even chiplet Ryzens, whose efficiency is degraded mainly by the presence and activity of the I/O die, cannot compete with Intel.
English translation and edit by Jozef Dudáš
With the little (E) cores turned off, the Core i5-13400(F) becomes a 6-core processor with 12 threads in the same way that the older Core i5-12400(F) is. This intergenerational comparison is also a side product of tests main goal of which is to show the impact of E cores not only on computational and gaming performance, but also on operational characteristics. The biggest differences occur in the situations that mainstream PCs run into most often.
Performance tests
Computing performance
Gaming performance
Disclaimer: The results in Total War Saga: Troy do not reflect well the comparison of Raptor Lake and Alder Lake processors, including the Core i5-13400(F) and Core i5-12400(F). The motherboard used, Asus ROG Strix Z790-E Gaming WiFi, achieves lower performance than other motherboards in this game for some reason. This is also shown by our comparative analyses.
With the little (E) cores turned off, the Core i5-13400(F) becomes a 6-core processor with 12 threads in the same way that the older Core i5-12400(F) is. This intergenerational comparison is also a side product of tests main goal of which is to show the impact of E cores not only on computational and gaming performance, but also on operational characteristics. The biggest differences occur in the situations that mainstream PCs run into most often.
Memory tests…
… and cache (L1, L2, L3)
With the little (E) cores turned off, the Core i5-13400(F) becomes a 6-core processor with 12 threads in the same way that the older Core i5-12400(F) is. This intergenerational comparison is also a side product of tests main goal of which is to show the impact of E cores not only on computational and gaming performance, but also on operational characteristics. The biggest differences occur in the situations that mainstream PCs run into most often.
CPU power draw curve
With the little (E) cores turned off, the Core i5-13400(F) becomes a 6-core processor with 12 threads in the same way that the older Core i5-12400(F) is. This intergenerational comparison is also a side product of tests main goal of which is to show the impact of E cores not only on computational and gaming performance, but also on operational characteristics. The biggest differences occur in the situations that mainstream PCs run into most often.
Average CPU power draw
With the little (E) cores turned off, the Core i5-13400(F) becomes a 6-core processor with 12 threads in the same way that the older Core i5-12400(F) is. This intergenerational comparison is also a side product of tests main goal of which is to show the impact of E cores not only on computational and gaming performance, but also on operational characteristics. The biggest differences occur in the situations that mainstream PCs run into most often.
Achieved CPU clock speeds
With the little (E) cores turned off, the Core i5-13400(F) becomes a 6-core processor with 12 threads in the same way that the older Core i5-12400(F) is. This intergenerational comparison is also a side product of tests main goal of which is to show the impact of E cores not only on computational and gaming performance, but also on operational characteristics. The biggest differences occur in the situations that mainstream PCs run into most often.
CPU temperature