Thursday, December 26th 2024
AMD Ryzen 9 9950X3D Carries 3D V-Cache on a Single CCD, 5.6 GHz Clock Speed, and 170 Watt TDP
Recent engineering samples of AMD's upcoming Ryzen 9 9950X3D reveal what appear to be the finalized specifications of the top-tier AM5 chip. The 16-core, 32-thread processor builds upon the gaming success of the Ryzen 7 9800X3D while addressing its core count limitations. The flagship processor features AMD's refined cache design, combining 96 MB of 3D V-Cache with 32 MB of standard L3 cache. Unlike its predecessor, the 7950X3D, the new Zen 5 architecture incorporates a redesigned CCD stacking method. The CCD now sits above the cache, directly interfacing with the STIM and IHS, eliminating thermal constraints that previously required frequency limitations. The processor features asymmetric cache distribution across its dual CCDs—one die combines 32 MB of base L3 cache with a 64 MB stacked V-Cache layer, while its companion die utilizes a standard 32 MB L3 cache configuration. In total, there is a 128 MB of L3 cache, with 16 MB of L2.
This architectural advancement enables the 9950X3D to achieve a 5.65 GHz boost clock across both CCDs, matching non-X3D variants. The processor maintains a 170 W TDP, suggesting improved thermal efficiency despite the additional cache. AMD's software-based OS scheduler will continue to optimize gaming workloads by directing them to the CCD with 3D V-Cache. Early leaks indicate the 9950X3D matches the base 9950X in Cinebench R23 scores, both in single and multi-threaded tests—a significant improvement over the 7950X3D, which lagged behind its non-X3D counterpart due to frequency limitations. AMD plans to expand the Zen 5 X3D lineup in Q1-2025 with both the 9950X3D and 9900X3D models. Full performance benchmarks and pricing details are expected at CES 2025, where AMD will officially unveil these processors alongside their RDNA 4 GPUs.
Sources:
@94G8LA, via VideoCardz
This architectural advancement enables the 9950X3D to achieve a 5.65 GHz boost clock across both CCDs, matching non-X3D variants. The processor maintains a 170 W TDP, suggesting improved thermal efficiency despite the additional cache. AMD's software-based OS scheduler will continue to optimize gaming workloads by directing them to the CCD with 3D V-Cache. Early leaks indicate the 9950X3D matches the base 9950X in Cinebench R23 scores, both in single and multi-threaded tests—a significant improvement over the 7950X3D, which lagged behind its non-X3D counterpart due to frequency limitations. AMD plans to expand the Zen 5 X3D lineup in Q1-2025 with both the 9950X3D and 9900X3D models. Full performance benchmarks and pricing details are expected at CES 2025, where AMD will officially unveil these processors alongside their RDNA 4 GPUs.
50 Comments on AMD Ryzen 9 9950X3D Carries 3D V-Cache on a Single CCD, 5.6 GHz Clock Speed, and 170 Watt TDP
I probably won't upgrade to this one until after 1 or 2 years. If this was like a 30% performance jump (its not, comparing 7800X3D to 9800X3D), then sure, but not $700 sure. :laugh:
Was kind of hoping they would do that as a 'lower' tier Ryzen 9 part and release a dual-CCD X3D top-tier Ryzen 9 CPU....
There's a reason, also with dual CCD, would having 32+32MB be as good as one CCD with 64MB 3D extra L3 cache ? if no, wouldn't 64+64 be too expensive ?
I think there are genuine cost and technological obstacles for dual CCD, it's not just them wanting to add a software director and more complexity, maybe further down the line
I'll be very disappointed if this turns out to be the final sku
There are still some limits like I said, they are not as big as gen 1, but there are still differences between 3D and non-3D clearly.
Anyway, as for the dual X3D part.... Someone will always pay for it even if the benefit is only 1% (or even less) over the next competitive product in the lineup, witness the 14900KS...
Heat dissipation wise 2nd gen X3D cache enabled chips are now identical to non-X3D chips:
gamersnexus.net/cpus/rip-intel-amd-ryzen-7-9800x3d-cpu-review-benchmarks-vs-7800x3d-285k-14900k-more
The above chart demonstrates that at a given heat load they are now about the same and thus the single limitation has been removed. Frequency has thus scaled according to that.
Lower binned parts having lower frequencies isn't evidence that said heat limit still exists, it merely demonstrates the obvious in the PC world that lower end parts often have lower frequency.
The technical hurdles for gaming (as opposed to the professional stuff with the Threadrippers) are not to be underestimated, however. Inter CCD latencies are still a thing and you would have to make sure that the scheduler always "fills up" a single CCD first (eight cores) before switching to the second CCD if more cores are needed (which will be the case in less than 1% of games btw).
AMD is doing the right thing here imo. A dual cache 99xx CPU would be very expensive and the real world returns would be minimal or even detrimental, depending on the game. The most critical factor for gaming is inter CCD latencies and you can only mitigate those latencies to a minor extent by having cache on both CCDs. You would still want any game to utilize only a single CCD for as long as possible before spilling over onto CCD #2.
The challenges with regard to scheduling would, in fact, become even more difficult. With 7950X3D it is "easy" because the 2nd CCD is simply put to sleep (core parking) but if you had dual cache on a 9950X3D, well, wow... that would open an all new palette of cans of worms when it comes to scheduling :) .
Games remain thread-limited. You can't just throw more cores at the problem and hope that all tasks are automagically split up between the cores. That's not how it works. Multithreading is very complex and most of the time other threads are waiting for one thread to finish their work.
Anyone who believes that they need more cores for gaming (should be very few people as only very few games effectively utilize more than four to six cores) is better off waiting for AMD to put more cores onto their CCDs. We'll have to wait and see if they will go straight from 8 to 16 or if there will be an intermediary step but for gaming that is the (our) ticket to success.
Dual CCDs will always remain a compromise for a home/gaming plus light productivity setup. Anyone with serious needs will go Threadripper/EPYC and anyone who is just gaming will always be better off with a single CCD CPU (9800X3D/7800X3D at the high end especially).
X3D only for 1 CCD blah, so are they still paring 1 good CCD and 1 worse CCD because that is the real crime. :laugh:
Give me hot or give me not !
j/k
/s
Someone really needs to do a performance per square mm (factoring in just the core size) to figure out how efficient Intel's big little is as compared to AMD. Should probably do one for AMD's dense cores as well.