It is. If you don't mind, I will explain how it works for you.
The 12-core Ryzen 9's have an unique topology, as they're basically two 6-core Ryzen 5's conjoined. For example, both the 5900X and 7900X are built out of two 5600X and 7600X "compute dies", respectively. The 5950X and 7950X processors are likewise built out of two 5800X and 7800X, respectively. With the new Ryzen 9 X3D's, AMD did something different: one compute die is identical to its standard counterpart, while the other is identical to its X3D counterpart. This means that they carry both the strengths and weaknesses of both types of CPUs - so the 7950X3D is built out of one 7800X and one 7800X3D die, and the 7900X3D is built out of one 7600X and one "7600X3D".
A long standing weakness of the 12-core Ryzen 9's has been the fact that they have 6 cores per CCD, which causes a relative performance regression compared to the 8- and 16-core models on applications which spread across 8+ CPU threads. This is because there is a certain penalty for synchronizing and accessing data on the other compute die, as well as a bandwidth bottleneck involved. The 16-core model isn't affected as badly because both partitions contain a full 8-core 16-thread processor complete with all of its resources, so in the worst case scenario for the 7950X3D, it'll not scale as well as the standard 7950X or an eventual model that would have two X3D-equipped compute dies. To help optimize scheduling and making sure that applications perform as well as they can, AMD provides a software driver that will cause Windows to attempt to throw certain workloads to a "side" of the processor, necessarily depriving programs of some of the other side's resources.
Specifically, in the case of the 7900X3D, you get hit by this problem two-fold: one is that it's 6+6 and thus affected by the aforementioned problem, and the other is that due to one of its compute dies being X3D equipped, one of the dies is slower and has even higher operating latencies, which causes this penalty to become more severe. The end result is that the 7900X3D is a master of none, all while also being unable to become a competent jack of all trades. It will perform at best like a 7600X or an eventual 7600X3D in a best case scenario - but it will never perform as well as a 7800X, 7800X3D or 7950X3D because of the nature of its design.
If you're curious about how a Ryzen 5 X3D would be, AMD made a limited run for the United States of the 5600X3D, and there is a review:
95% of the 5800X3D’s gaming performance for 20% less cash
www.tomshardware.com
Unfortunately, it was not released worldwide, and since W1zzard is based in Germany, I believe he was not sampled as there is no TPU review of it.
Someone can't help themselves
But it's OK, take our advice to heart and buy the 9800X3D this time around.
