AMD Zen 5 Memory Performance Scaling: When Too Fast is Bad

The adoption of DDR5 memory on modern platforms has brought significant advancements in bandwidth and data transfer rates, and AMD's Ryzen 9000 AM5 platform is no exception. As DDR5 memory becomes more mainstream, the potential for performance scaling across various memory speeds offers an opportunity to understand how different configurations impact overall system behavior. In this review, we investigate the scaling of DDR5 memory on Ryzen 9 9950X, running speeds from DDR5-8000 down to the JEDEC baseline specifications of DDR5-5600 and DDR5-4800. These tests aim to highlight the performance gains and any potential trade-offs when pushing DDR5 memory beyond the standard specifications. We're also doing testing at the interesting DDR5-6000 CL28 setting as well as DDR5-6400 with UCLK 1:1.

Intel Core i5
Core i5-12400F
Core i5-13400F
Core i5-12600K
Core i5-13600K
Core i5-14600K
AMD Ryzen 5
Ryzen 5 8500G
Ryzen 5 5600X
Ryzen 5 7600
Ryzen 5 7600X
Ryzen 5 9600X
Intel Core i7
Core i7-12700K
Core i7-13700K
Core i7-14700K
AMD Ryzen 7
Ryzen 7 5700G
Ryzen 7 5700X
Ryzen 7 7700
Ryzen 7 7700X
Ryzen 7 9700X
Ryzen 7 5800X
Ryzen 7 5800X3D
Ryzen 7 7800X3D
Intel Core i9
Core i9-12900K
Core i9-13900K
Core i9-14900K
AMD Ryzen 9
Ryzen 9 5900X
Ryzen 9 7900
Ryzen 9 7900X
Ryzen 9 7900X3D
Ryzen 9 9900X
Ryzen 9 5950X
Ryzen 9 7950X
Ryzen 9 7950X3D
Ryzen 9 9950X

[pfandahalf]

I like how techpowerup gets straight to the point.

[blleman]

Ahhh there's a techpowerup channel. Subscribed !

[spladam]

I wish all tech videos could be more like Tech PowerUp. Thanks folks.

[exscape]

It's very misleading (actually strictly speaking incorrect) to say AMD officially supports DDR5-6000. The highest officially supported (guaranteed to work) speed is DDR5-5600. 6000 almost always works (1:1), but is not supported.

[datsweetsansabooty]

Went straight into the video and didn’t even asked me to subscribe, so I’m subbing.

[weirdodude]

For my 9700X I have a DDR5-6000 CL30 kit that is running at 6200 CL30 with slightly increased voltages, it seems really good. Thumbs up!

[TheRealDlo]

I've been using DDR5 6400 CL32 for awhile and everyone said I didn't know what I was doing... 👍

[PowellCat]

1:30 6400 is very doable on Ryzen 9000 now due to IOD improvement. Recent batches of Ryzen 7000 can also run 6400 with low SOC voltages.

[read]

This video fails to mention infinity fabric, there is a noticeable dip in latency when running FCLK at exactly 2/3 UCLK so that would be 2133 @ 3200 UCLK or 6400 MT/s (2133 is about where AMD FCLK tops out at which is why you never see anyone going for 7200-8000 etc.)

Edit: I saw in a comment that you guys did your tests @2100, try bumping to 2133 @ 6400 and you should get your best results by far

[PadPoet]

Never knew you guys had a YouTube channel, subbed!

[AceStrife]

The memory timings being all over the place does not make this a 1:1 test between any single instance, especially the 5600 with massively loose timings compared to 6000 (CL especially).

I get it's extremely difficult to find a memory kit capable of the same timings at higher speeds, but still, this variance does impact results, quite significantly in some cases.

[RobloxianX]

Good thing that G.Skill just released it's DDR5-6400 CL30 kits, it'll be perfect for a Ryzen 7 9800X3D and RTX 5090 build

[StudyWithNika]

looking forward to similar ram testing videos for upcoming intel cpus ❤

[tanmay]

most detailed ddr5 scaling I have ever seen. Thank you

[syncmonism]

Great video. Usually you don't see such accurate, useful, and empirically backed up information about such a complex topic in such a short and concise video.

[irataoforfun]

I read the complete article, but the video resume beatifully, thanks for the work.

[mikeramos]

Upgraded from 32gb 6000mhz cl36 to 64gb 6600mhz cl32 & noticed a difference.

[Crossfire]

When running my Kingston memory kit at EXPO-6400MT/s CL32, or at EXPO-6000MT/s CL30 with my Ryzen 9 9950X, MemTest86 would display errors, so I had to drop the frequency at 5800MT/s while keeping the EXPO-6000 timings (CL30-36-36-80, 1.4V) in order to have a 100% stable system.

I guess, there's a reason why AMD only supports, officially, DDR5-5600...

[marknikolich]

AES Encryption is accelerated with higher bandwidth so technically 8000 is still better 🙂 But in all honesty its not worth the money for the average user, but for a power user depending on what programs were tested, I'm not sure what techpowerup used for every single setting and test but my tests show up to 25% performance increase if latency is balanced between the optimum frequencies ie. 6400 and 8000. but some applications and even games can also have a negative hit so it depends on the owners use case. For example, a single PC streaming setup using cpu rendering, I seen a performance boost up to 10% for 1% lows in games if the ccd's are split with process lasso with the Game & OBS, since bandwidth is increased overall thorouput is also inscreased. So my conclusion is if you have the money and need the bandwidth do 8000, but if not, then you just don't waste your time. It is very hard to optimized and tighten the timings with Ryzen at 8000 to the point I deemed it not really worth it lol. Cheers all.

[Nintendokater]

0:06 "Fast" is a very unsharp word. Fast in terms of clock rate, or in FP32 performance? Anyway, depending on the definition, there are several models that are "faster"