Anandtech has managed to procure a Core i7-11700K retail unit via Mindfactory and found that Intel’s Rocket Lake-S CPU suffers from high power draws and high temperatures indicating the pitfalls of backporting a 10 nm architecture to 14 nm. The Core i7-11700K did have a significant advantage in the esoteric AVX-512 tests but fell behind the Ryzen 7 5800X in a majority of CPU benchmarks. Despite claims of a 19% IPC uplift, gaming performance took a hit due to higher L3 cache latency.
So far, Intel only spoke about the “flagship” Core i9-11900K Rocket Lake-S processor during CES 2021. Details about the rest of the lineup are still under embargo till March 30 although we have seen price leaks already.
Recently, it came to light that German retailer Mindfactory apparently sold nearly 120 pre-launch Core i7-11700K units for €469 apiece weeks before the official embargo lift. Anandtech managed to get hold of the Core i7-11700K from Mindfactory and put out an early review while managing to work around Intel’s embargo conditions.
Spoiler alert: The Core i7-11700K has turned out to be a disappointment, especially in gaming.
We encourage you to read Anandtech‘s excellent review, but here are some key takeaways. Do note that Intel hasn’t seeded the final microcode for these processors yet, so minor performance improvements can be expected in the run-up to the official launch.
Right off the bat, Anandtech‘s AVX2 and AVX-512 tests show increased temperatures and power draws. Though Intel lists the TDP of the Core i7-11700K as 125 W, there is no real upper power limit for turbo performance. An AVX2 workload such as POV-Ray causes the power consumption to rise to 200-225 W with a temperature peaking at a decent 81 °C and all-core turbo at 4.6 GHz. Do note that Intel originally said that an “8-core Rocket Lake-S” will have a PL1 of 125 W and a PL2 of 250 W.
Shifting the load to AVX-512 shows the power draws rising to 292 W and core temperatures hitting 104 °C overall. On a related note, many industry veterans including Linus Torvalds feel that Intel is pushing AVX-512, which is traditionally meant for servers, to consumer products as a gimmick just so that it can demonstrate a lead over AMD in such benchmarks. Incidentally, the Core i7-11700K scored way higher in AVX-512 loads than any other processor in comparison, particularly the AMD Ryzen 7 5800X.
Elsewhere, the Core i7-11700K is seen to trail behind the Ryzen 7 5800X in benchmarks such as Cinebench R20, 7-Zip, Handbrake 1080p30 to 4K60 H.264 encode, and web-based benchmarks. However, Rocket Lake-S does seem to have a slight lead over Zen 3 in Blender and POV-Ray.
Coming to gaming, Anandtech‘s results show a regression in performance despite Intel’s claims of a 19% IPC uplift over the previous generation. In all gaming tests, with the exception of Gears Tactics, the Core i7-11700K seems to have been outclassed by the Ryzen 7 5800X, particularly at 720p and 1080p resolutions where the CPU often tends to become a bottleneck. The performance difference between the Ryzen 7 5800X and the Core i7-11700K becomes even more apparent at resolutions lower than 1080p.
Overall, the initial benchmarks seem to point out the disadvantages of backporting a 10 nm architecture to a 14 nm process. That, along with forced AVX-512, seems to have resulted in a bigger chip that tops-out at just eight cores and is more power hungry than its predecessors and the competition.
Anandtech notes that Intel’s 19% IPC uplift claim isn’t entirely false, but it applies largely to floating point workloads than the more common integer ones, where the benefits lie in the 7-13% range. The regression in gaming performance is likely to due to the higher L3 latency (51 cycles compared to last gen’s 43) going up to 28-30 ns compared to 18-24 ns in Comet Lake. The reason for this higher L3 latency is not yet known, and we may have to wait till the official architecture presentation closer to launch to know more.
Ultimately, Rocket Lake-S’s success will depend on pricing and availability. With the current uncertainty in CPU stocks showing no signs of abating soon, DIY PC builders aren’t left with too many choices but to go for whatever SKU is available in stores.
With Intel touted to launch the hybrid Alder Lake-S processors on a new LGA 1700 socket in just six months from now with support for DDR5 and possibly PCIe Gen5, the company may have a tough time in getting to convince customers to go for a Rocket Lake upgrade.
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