Core i5-12400, Core i5-12400F Hit eBay For $365 and $323. A significant number of Intel Core i5-12400 "Alder Lake" engineering samples (ES) have been listed on eBay. The Intel i5-12400 is a mid-range processor with 6-core/12-thread processor that only has 6 Golden Cove performance cores and no Efficiency cores 

These procs now have been spotted on eBay as engineering samples, but you'd be better off to dismiss these. The ES chips now in circulation may be plagued by incompatibility difficulties with the Z690 motherboards currently available on the market.

It seems there are two unreleased iterations of the i5-12400 floating around Videocardz noticed, designated C0 and B0, with the former serving as a QS or qualifying sample and the latter serving as an ES or engineering sample. The maximum boost frequency of the two devices is different: 4.40 GHz versus 4.00 GHz. Additionally, they differ from the S-SPEC codes QXDY and QYHX. It appears that even with production versions of firmware and Intel ME, retail Z690 motherboards do not guarantee compatibility with the samples in this report.

There is a significant difference between the two, such as a different boost frequency of 4.4 GHz against 4.0 GHz, among other things. In addition, the QXDY sample features a different integrated GPU than the other samples. Instead of the anticipated UHD 730 graphics, it is equipped with HD 770 graphics instead. For all intents and purposes, it could just as easily be an Intel Core i5-12600 prototype that reportedly includes similar graphics. On Zhuanlan, you may find a lengthy and detailed description of each of the engineering samples that were used. In the case of a purchase of an early engineering sample, it will simply mean that the CPU will not function unless it is connected to a motherboard that has an older microcode/management driver.

Core i5-12400 Engineering Samples Hit eBay, Reveals Lots of Compatibility Issues