I'm finishing a gaming PC with a Ryzen 7 7800X3D and Radeon RX 9070 XT, mainly targeting 1440p. DDR5 prices are unusually high, and I'm comparing these 32GB (2×16GB) kits:
- €310: DDR5-5600 CL46 Crucial Pro
- €380: used DDR5-6400 CL32 with Hynix A-die and EXPO/XMP
- €440: new DDR5-6400 CL32 kit
Would DDR5-5600 CL46 cause any stability, 1% low, frametime, or EXPO-related problems with the 7800X3D, or would it simply provide somewhat lower performance than faster, tighter-timed memory? I'm leaning toward the €310 kit because it's much cheaper and easier to obtain, but I don't want to regret the decision. Would the used 6400 CL32 kit be worth paying €70 more for, or should I spend €130 extra on the new one?
3 Answers
The main weakness of the 5600 kit is the very loose CL46 timing. It will not cripple gaming, but certain CPU-limited titles may show a measurable difference in average FPS or 1% lows compared with a well-tuned 6000 or 6400 kit. I wouldn’t pay €130 more for the new kit purely for gaming, though. If the used Hynix kit is from a trustworthy seller and passes memory tests, the extra €70 is the option I’d consider; otherwise, save the money and get the 5600 kit.
DDR5-5600 CL46 will work normally with the 7800X3D. It won’t cause special stability or frametime problems just because the timings are loose; it’s simply slower memory. The performance difference is usually modest with an X3D processor, especially at 1440p where the GPU is often the limiting factor. Given the current prices, I’d be comfortable choosing the €310 kit.
The 6400 CL32 kit is clearly better on paper, and Hynix A-die gives you more room to tune timings or overclock later. Some CPU-heavy games can benefit from faster or better-tuned memory, so the used kit could be a reasonable middle ground if you can verify that it works properly. Still, DDR5-6400 is not guaranteed to run at its rated speed on every AM5 system; DDR5-6000 is often the easier balance for Ryzen.
You can always run the 6400 kit at 6000 or lower if the integrated memory controller doesn’t handle the full speed reliably.
If you’re worried about future regret, you could buy the faster kit and run it at a lower speed if needed, but that only makes sense if the extra cost is comfortable.