Intel has used the same basic processing core layout in its desktop CPUs for many years, but the upcoming Arrow Lake architecture seems to change things up a bit. Whereas recent designs have featured two rows of main cores (performance cores) followed by several banks of efficient cores, Arrow Lake may change to a repeating arrangement of blocks containing two banks of four P cores and four E cores. And it could all be due to the use of rentable units.

The idea that Intel might change the core arrangement of its processors was suggested by Kepler_L2 at X and confirmed by Bionic_Squash.

The block diagram in this post is a mockup of the P- and E-core arrangement that Intel is said to be using in Arrow Lake, showing a design in which four P cores repeat the pattern of two banks of four E cores surrounding them.

This is markedly different from the core layout of the latest architectures, Meteor Lake and Raptor Lake Refresh, and if the diagram is correct, this would be the first major change in core This would be the first major change in core layout since Intel introduced E-cores in its Alder Lake desktop chips in 2021. In fact, Intel's layout has changed little since Sandy Bridge in 2011.

Back then, the Core i7 2700K, for example, had four cores side by side, all connected to a ring bus that allowed faster access to the shared L3 cache. With each generation of chip design, Intel added more cores by simply lengthening the rows and adding a second row. The last architecture before the hybrid era, Rocket Lake in 2021, consisted of two rows of four cores with a bus between the rows.

That did not change when E-cores were introduced in Alder Lake, they were simply added to the end of the P-core row and the ring bus lengthened accordingly; Raptor Lake Refresh still does so, and the small Meteor Lake laptop CPU's Even the compute tiles are laid out this way.

The Kepler_L2 diagram, however, is markedly different. However, the scale of this change suggests that it could be more significant than this, and another possibility is that Intel is road-testing the Rentable Units (RU) idea in Arrow Lake.

This was patented by Intel some time ago and is essentially a complex circuit that partitions threads based on instruction complexity and issues that partition to the appropriate P or E core, depending on what needs to be processed in that partition.

By having one block of four P-cores and eight E-cores, Intel was able to design Arrow Lake so that each block had its own RU, making it relatively easy to build something that could scale. The lowest tier models have one or two blocks and some cores are disabled, but the highest spec processors can have four or more blocks.

Intel will also want to take full advantage of the Skymont E-core design in Arrow Lake. This new efficiency core is claimed to have a higher IPC (instruction rate per clock) than Raptor Lake's P core, which is why Intel did not include hyper-threading (HT) hardware in Lunar Lake's P core.

It has long been rumored that Arrow Lake will not have HT either, so a 15th generation Core processor with 8 P-cores and 16 E-cores would only be a 24-thread chip. This is quite a drop from the 32 threads supported by the Core i9 14900K, so it is unlikely that Intel will do this for a high-end Arrow Lake desktop CPU.

However, they might do it for lower-end models like the i7 and i5 to make their most powerful processors stand out more. Then again, it doesn't make much sense to use RU and HT at the same time, since the general idea is that the former is more flexible than the latter.

Of course, two people on social media saying that this is what the core layout of Arrow Lake looks like is by no means concrete evidence of a change, nor is it a complete indication that rental units are on the way.

But if all of that is true, and Intel has been working on improving the use of P and E cores, this change would be very welcome, especially considering how much Intel has improved efficiency cores for Lunar Lake. [For PC gaming, 6-8 P-cores with HyperThreading is still more than enough for most games, so it probably won't make much difference, but for content creation, better multithreading performance is a must. 16-core Ryzen with AMD Zen 5 processors are coming to market soon and will almost certainly set a new bar for multicore speeds, this is especially important

.