Monday, May 8th 2023
Latest AMD AGESA that Nerfs Ryzen 7000X3D Voltage Control Also Limits Memory Overclocking
The latest AMD AGESA 1.0.0.7 AM5 platform microcode that the company recently released to improve stability of machines powered by Ryzen 7000X3D processors, more importantly, prevent them from physical damage due to increased voltage in voltage-assisted overclocking scenarios; reportedly impacts memory overclocking capabilities, too, reports g01d3nm4ng0. The "PROCHOT Control" and "PROCHOT Deassertation Ramp" toggles that were available in the oldest versions of AGESA for AM5, are not available in the latest production AGESA.
The memory compatibility is also affected. AMD recently added support for odd-density DDR5 memory modules, such as 24 GB and 48 GB, which make up 48 GB and 96 GB 2-module (dual-channel, four sub-channel) kits. It is possible to max out 192 GB, but while the older AGESA 1.0.0.6 allowed memory frequencies of up to DDR5-6000 with SoC voltage of 1.3 V, the newer AGESA is only stable up to DDR5-4400 at this density. To be fair, most motherboards advertise maximum memory frequencies of under DDR5-4800 for memory configurations where there are two DIMMs per channel, and both DIMMs are dual-rank (so four dual-rank DIMMs in all, which is the least optimal memory configuration from a memory frequency and latency perspective).
Source:
g01d3nm4ng0 (Twitter)
The memory compatibility is also affected. AMD recently added support for odd-density DDR5 memory modules, such as 24 GB and 48 GB, which make up 48 GB and 96 GB 2-module (dual-channel, four sub-channel) kits. It is possible to max out 192 GB, but while the older AGESA 1.0.0.6 allowed memory frequencies of up to DDR5-6000 with SoC voltage of 1.3 V, the newer AGESA is only stable up to DDR5-4400 at this density. To be fair, most motherboards advertise maximum memory frequencies of under DDR5-4800 for memory configurations where there are two DIMMs per channel, and both DIMMs are dual-rank (so four dual-rank DIMMs in all, which is the least optimal memory configuration from a memory frequency and latency perspective).
73 Comments on Latest AMD AGESA that Nerfs Ryzen 7000X3D Voltage Control Also Limits Memory Overclocking
1.35 VDD for your memory is absolutely fine and 100% safe.
Not sure what SOC needs to hit 6000 cl30 but that seems to be the sweet spot.
I’ve seen a few posts with 7000-7200 if I recall, but then you can’t maintain mclk:uclk @ 1:1, so performance takes a nose dive.
With 6600 c28-c30 you can shave another 2-3ns off latency and get some additional bandwidth over 6400. Requires a lot of VDD(vdimm) and good 7000 chip.
This is the max difference I could find without tuned subs between 6200CL34 and higher ram speeds (13900K with 4090) -- the jump of 1000mhz on the ram netted 3fps at the lows and 7.6% at the averages - so with less headroom than this... scaling is what - 5% max? I wouldn't say that's plenty -- that's basically you couldn't tell the difference unless you were staring at a framerate graph.
If you're saying "Im nerfing memory from 8000 to 6000" then yes- that's a huge nerf... outliers that can do 6600 aside (and even then) at most this is a 5% difference given the same timings? Probably less once you tighten timings on the faster kits as low as they will go.
As Long as I can install 32GB of DDR5-6000 CL30 or faster, then like a lot of users, I would never run into the issue above. But its seems the memory compatibility pages for mobo makers still need updating -
www.msi.com/Motherboard/MAG-X670E-TOMAHAWK-WIFI/support#mem
It will vary from game to game, but from personal testing going from c36 6000 expo to 6200 c30 tightening primary/secondary/tertiary was about a 6% gain in CP2077 at 1080p low preset. I can probably test 6400 now that I have a good kit of A-die.
That being said -- most people don't really tune subs, and to them 6000 to 6600 or 6400 EXPO is going to be very little difference for the reason above. For the people that DO tune subs the focus on OCing will fall to the timings -- and a C26/C28 6200 with aggressive primary/secondary/tertiary will still net a huge performance boost, -- maybe you will lose 5% not being able to go to 6400/6600 if that's the sweet spot of the kit... but the difference isn't going to massive in either case.
They could have a c32 6000 kit and a c32 6400 kit with a 1% difference or less when set to expo. The 6000 kit could have very tight sub timings like trfc, terfi, for some hefty gains. The 6400 kit could have the most abysmal trfc and trefi at almost double/half the other kit. This will vary from kit to kit, brand to brand, and even worse mobo vendor to mobo vendor as most of them will define their own timing rules for secondary/tertiary as dram vendors don’t always seem to define those values in xmp/expo profiles (or autocorrection takes over).
So technically to say there’s no scaling just is not true; ticking expo and dialing up the frequency while having no idea what the motherboard is setting sure.
Id say overclocking has changed, and requires a lot more finesse and understanding than previous brute forcing methods in the past. And again, sadly, reviewers don’t have the time or luxury to spend actually testing or showing this.
Every IMC will be different but this is what I'm needing for stability. Basically at least on this GB Elite AX motherboard you need to manually set the VDDIO_Mem because it just stays at 1.1V otherwise. I assume the DDR5-6000 is still a thing, but some for some that may be 5600 now. Dependent on the IMC.
Yes, Gigabyte still allows over 1.3V, you just get a warning now is all...
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Just looked at the listenings over at heise.de. 170 kits listed with AMD EXPO, and their voltage specs:
If you narrow it down to kits that are specified for 6000MHz (AM5 sweet spot) there are left 65 kits. Their specified voltages are:
Which means you have only 5 kits that run within AMD's specs at 6000MHz (from TeamGroup, Apacer & Lexar). 60 kits are certified by RAM vendors to run outside of AMD's specs! Which btw. does not mean they won't run with lower voltages. It's just not guaranteed to run at lower voltages. Each kit is of different qualitiy and RAM vendors just set higher voltages to guarantee compatibility across the board.
I guess the solution would be to use/develop RAM kits that run with lower voltages. It kinda reminds me of the DDR3 times when all vendors had kits running on 1.5+V and G.Skill came around the corner with their "G.Skill ECO Series" which did run on only 1.35V. It also marked the rise of the 1.35V kits.
On a side note regarding the AMD burnout issues in general, my number one question is how will all this be wrapped up after the issue is fully resolved. The issue is rare but people don't want to be left hanging on a thread wondering if their motherboard could have degraded their CPU. AMD should make it clear to customers the scope of potentially affected CPUs, whether that be all AM5 CPUs on any AM5 board or just certain motherboard models and only if EXPO was enabled and offer an expedited RMA to all those potentially affected CPUs. I think the worst thing AMD could do is fix the issue but not clarify to customers who could have had their CPUs potentially degraded, especially for those that enabled EXPO.