The Intel Core i9-10910, which is believed to be an Apple-exclusive chip (opens in new tab), has shown its face on Geekbench 5 (opens in new tab) again. Without confirmation from Intel, of course, we can't be positive of the accuracy of the results, spotted by @Leakbench (opens in new tab). But this allows us to do an early pseudo-assessment of the CPU's (opens in new tab) performance.
The Core i9-10910 in question, as well as the current Core i9-10900, belong to the 10th Generation Comet Lake-S (opens in new tab) family. The 14nm processors find their home inside the new LGA1200 CPU socket. They're equipped with 10 CPU cores, 20 threads and 20MB of L3 cache. One theory as to the Core i9-10910's existence is that Apple wants a custom chip for its iMac.
For context, the Core i9-10900 has a 2.8 GHz base clock and a 5.2 GHz TVB (Thermal Velocity Boost) clock. Today's Geekbench 5 submission (opens in new tab) paints the Core i9-10910 with a 3.6 GHz base clock and a boost clock that almost hits 5 GHz. The most attractive aspect of the Core i9-10900 is the fact that the processor is rated for 65W, so it isn't overly demanding on cooling or power delivery. The finer details of the Core i9-10910 are still unknown at this point, so we don't know if there is a change in the TDP (thermal design power) or not.
The two Geekbench 5 results depict exactly what the specifications already hinted. The Core i9-10910 excelled in single-threaded workloads but ultimately lost to the Core i9-10900 when multi-threaded workloads are involved.
Despite the 28.6% higher base clock, the Core i9-10910 only delivered up to 6.9% higher single-core performance than the Core i9-10900 in Geekbench 5. The tables turned when it comes to multi-core performance though. The Core i9-10900 outperformed the Core i9-10910 by 9.6%.
Assuming these results are correct, it shouldn't be hard to pick between a Core i9-10910 or Core i9-10900. You'd just have to identify the type of workloads you commonly execute on your system. The Core i9-10910 purportedly has better single-core performance, and the Core i9-10900 is expected to offer superior multi-core performance.