See https://www.phoronix.com/review/amd-ryzen-9-9950x3d-linux/10
> Here is the side-by-side of the Ryzen 9 9950X vs. 9950X3D for showing the areas where 3D V-Cache really is helpful:
Coincidentally, it looks they filtered to all benchmarks with differences greater than 2%. The biggest speedup is 58.1%, and that's just 3d vcache on half the chip.
I’m curious to see whether the same benchmarks benefit again so greatly.
So for 9950X3D half of the cores use a small L3 cache.
For applications that use all 16 cores, the cases where X3D2 provides a great benefit will be much more frequent than for a hypothetical CPU where the same cache increase would have been applied to a unified L3 cache.
The threads that happen to be scheduled on the 2nd chiplet will have a 3 times bigger L3 cache, which can enhance their performance a lot and many applications may have synchronization points where they wait for the slowest thread to finish a task, so the speed of the slowest thread may have a lot of influence on the performance.
Agree. The article's 2nd para notes "AMD relies on its driver software to make sure that software that benefits from the extra cache is run on the V-Cache-enabled CPU cores, which usually works well but is occasionally error-prone." - in regard to the older, mixed-cache-size chips.
> I'm curious to see...
Yeah - though I don't expect current-day Ars Technica will bother digging that deep. It could take some very specialized benchmarks to show such large gains.
How critical of the lazy writers I am may seem outsized, but I grew up reading and learning from the much better version of Ars -one I used to subscribe to.
I might even shell out for an upgrade to AM5 and DDR5. On the other hand, my 5900X is still blazing fast.