Intel's Monstrous 144-Core Sierra Forest Xeon CPU With 172MB Of Cache Gets Benchmarked

hero intel sapphire rapids xeon 4th generation
If you haven't heard about Intel's Sierra Forest Xeons, then no, you haven't had too much coffee, and yes, you read that headline correctly. These upcoming processors are massive chips that eschew P-cores entirely for a giant platter of tiny little E-cores. That's left some wondering about performance, and while we indeed have a benchmark leak today, it's probably not going to answer any of your questions.

The leak in question comes, as it often does, from the Geekbench database. There, the tearless retina of the Benchleaks bot noticed a result from a "Genuine Intel Xeon" machine with 288 cores. It describes itself as "Intel Corporation BeechnutCity", which just so happens to be a dual-socket reference evaluation platform for LGA 4677. Given the presence of 288 cores, we assume this machine is packing a pair of Sierra Forest parts, as the 288-core model will probably be exclusive to the LGA 7529 socket.

geekbench screenshot cropped beechnutcity

The benchmark scores appear to only be for one of the two CPUs in the machine, but even at that, the results aren't impressive in the least. The single-core score of 855 is somewhere in the approximate range of an Ivy Bridge Core i7-3770, while the multi-core score of 7770 is barely 9 times more than the single-core score—an awful showing for a system with 144 cores per socket. For perspective, a Ryzen 7 3700 scores around 7500 in this test.

Given that this is a reference platform, and given the outrageously poor score, we rather think that something went wrong with the benchmark or possibly the system itself. It's likely that the 2.2 GHz clock rate reported by Geekbench is indeed the intended base clock of the CPU, but perhaps it wasn't able to hit that, or possibly the benchmark was confused by the absurdly-high core count in the machine. Even if everything was working as intended, we doubt Geekbench will scale out to 144 cores—yet we know it will scale past 10 cores, so something is definitely wrong.

xeon processor roadmap

Whatever the case, we absolutely don't believe that these results reflect the final performance of Sierra Forest, so don't draw any conclusions about those chips from this benchmark. We can still glean useful data from the result, though. Geekbench confirms the rumored 96KB L1 cache per CPU core, and a 4MB L2 cache for each E-core cluster. The listing also confirms the enormous 108MB L3 cache; that should help considerably with inter-core communication.

Intel has committed to launching its 5th-generation Xeon Scalable family, codenamed Emerald Rapids, a week from now on the 14th. After that, Sierra Forest should be the next launch for the company's Datacenter and AI Group (DCAI). These parts are currently expected to arrive in Q1 of next year, with a possible announcement around CES.