Thursday, March 17th 2022
AMD's Robert Hallock Confirms Lack of Manual CPU Overclocking for Ryzen 7 5800X3D
In a livestream talking about AMD's mobile CPUs with HotHardware, Robert Hallock shone some light on the rumours about the Ryzen 7 5800X3D lacking manual overclocking. As per earlier rumours, something TechPowerUp! confirmed with our own sources, AMD's Ryzen 7 5800X3D lacks support for manual CPU overclocking and AMD asked its motherboard partners to remove these features in the UEFI. According to the livestream, these CPUs are said to be hard locked, so there's no workaround when it comes to adjusting the CPU multiplier or Voltage, but at least AMD has a good reason for it.
It turns out that the 3D V-Cache is Voltage limited to a maximum of 1.3 to 1.35 Volts, which means that the regular boost Voltage of individual Ryzen CPU cores, which can hit 1.45 to 1.5 Volts, would be too high for the 3D V-Cache to handle. As such, AMD implemented the restrictions for this CPU. However, the Infinity Fabric and memory bus can still be manually overclocked. The lower Voltage boost also helps explain why the Ryzen 7 5800X3D has lower boost clocks, as it's possible that the higher Voltages are needed to hit the higher frequencies.
That said, Robert Hallock made a point of mentioning that overclocking is a priority for AMD and the Ryzen 7 5800X3D is a one off when it comes to these limitations. The reason behind this is that AMD is limited by the manufacturing technology available to the company today, but it wanted to release the technology to consumers now, rather than wait until the next generation of CPUs. In other words, this is not a change in AMD's business model, as future CPUs from AMD will include overclocking.
Hallock also explained why AMD didn't go with more cores for its first 3D V-Cache CPU and it has to do with the fact that most workloads outside of gaming don't reap much of a benefit. This is large due to how different applications use cache memory and when it comes to games, a lot of the data is being reused, which is a perfect scenario for a large cache, whereas something like video editing software, can't take advantage of a large cache in the same way. This means that AMD's secret to boosting the performance in games is that more game data ends up sitting closer to the CPU, which results in a 12 ns latency for the CPU to retrieve that data from the L3 cache, compared to 60-80 ns when the data has to be fetched from RAM. Add to this the higher bandwidth of the cache and it makes sense how the extra cache helps boost the performance in games.
For more details, please see video below. The interesting part starts around the 45:30 mark.
It turns out that the 3D V-Cache is Voltage limited to a maximum of 1.3 to 1.35 Volts, which means that the regular boost Voltage of individual Ryzen CPU cores, which can hit 1.45 to 1.5 Volts, would be too high for the 3D V-Cache to handle. As such, AMD implemented the restrictions for this CPU. However, the Infinity Fabric and memory bus can still be manually overclocked. The lower Voltage boost also helps explain why the Ryzen 7 5800X3D has lower boost clocks, as it's possible that the higher Voltages are needed to hit the higher frequencies.
Hallock also explained why AMD didn't go with more cores for its first 3D V-Cache CPU and it has to do with the fact that most workloads outside of gaming don't reap much of a benefit. This is large due to how different applications use cache memory and when it comes to games, a lot of the data is being reused, which is a perfect scenario for a large cache, whereas something like video editing software, can't take advantage of a large cache in the same way. This means that AMD's secret to boosting the performance in games is that more game data ends up sitting closer to the CPU, which results in a 12 ns latency for the CPU to retrieve that data from the L3 cache, compared to 60-80 ns when the data has to be fetched from RAM. Add to this the higher bandwidth of the cache and it makes sense how the extra cache helps boost the performance in games.
For more details, please see video below. The interesting part starts around the 45:30 mark.
222 Comments on AMD's Robert Hallock Confirms Lack of Manual CPU Overclocking for Ryzen 7 5800X3D
Energy efficiency SuperPI and CB
Since 5800X and 5950X has same power limits stock they generally use the same power when stressed max (140W-ish) and in multicore 5950X would win.
I never said 10900K was a toaster, 11900K on the other hand ;)
What you are seeing there is power consumption, not efficiency.
I'd be surprised if anyone buying Intel would be doing it because Intel is efficient
Intel has always been the choice for overclocking which is the opposite of what efficiency is in other words overclocking Intel systems can effectively score higher in benchmarks :laugh:
But in general 5800X beats the crap out of 10900K in almost every scenario on efficiency. In gaming stock it performs better and uses 30W less in the TPU test.
In gaming im sure they are pretty similar as well, zen 3 consume a lot during gaming, dunno why
Keeps the argument going.
Your statement was that they are equally efficient, mine is that they are not except in rare cases.
In what cases is a 125w 10900k not equally efficienct to a 125w 5800x? Can you show me some numbers?
Not really there are some people that just like to argue on lame points.
Professional forum instigators it's best to pass by them and not take the bait.
Forgot they also make snotty remarks to.
In cinebench 5800X is much more efficient at 125W since it already beat the 10900K stock while using less stock.
The argument comparing a 8 core against a 10 core is silly and should of been the first clue to pass.
Please hear what Steven says in the video: "That makes it more efficient that 10900K in just about every workload including games in almost every instance." Also see what the consumption numbers were on TPU, chekc Tomshardware, it performs similar to 5800X but consumes much more in viritually everything. Ryzen 7 5800X Power Consumption, Thermals - AMD Ryzen 7 5800X Review: The Pricing Conundrum | Tom's Hardware (tomshardware.com)
Handbrake:
106W vs 206W
Y-cruncher:
112W vs 185W