JUHOR DDR5-6400: The memory that isn’t DDR5-6400 anywhere, not even in China!
When we talk about memory on this page, it’s usually in the context of a review or overclocking experiment. However, this time, we have to address a different topic and issue a warning to those who purchase DDR5 memory from AliExpress.
Let’s introduce the memory kit in question, which is sold by JUHOR on AliExpress. With their DDR5 memory modules, they offer models ranging from 4800 to 6400 MT/s, in 8 GB or 16 GB modules, which can be purchased separately or in 16 GB or 32 GB kits. The product we’re reviewing here is a 16 GB kit with two 8 GB modules, which on paper boasts a clock speed of 6400 MHz, timings of 39-39-39-80, and an operating voltage of 1.4V.
The memory sticks are packaged in a transparent blister pack, which provides a clear view of the product. The packaging also includes a printed label for brand identification. It’s worth noting that we purchased these memory modules as two separate “8 GB 6400MHz” units, although they are also available as a 2x8GB kit, which may feature different packaging. Overall, the packaging is fairly standard and doesn’t offer any notable features or extras. Nonetheless, it serves its purpose of protecting the memory modules during shipping and storage.
The JUHOR DDR5-6400 memory module features a simple white aluminum heatsink without any lighting. However, one thing that might put off users looking for a more stylish build is the green PCB, which looks outdated compared to the trend of RGB lighting and aesthetically pleasing components.
Upon removing the heatsink, we discovered that the thermal interface only covered the memory chips, leaving the PMIC exposed. This design choice may not be an issue with an 8 GB module due to its lower power consumption, but it could present challenges with higher-capacity modules, such as the 16 GB or 32 GB kits. This is because the PMIC can get quite hot under heavy loads, as more ICs draws more power.
Regarding the memory chips, JUHOR opted to use the Hynix H5CG46MEB0, also known as Hynix M-Die. This is the first-generation DDR5 chip from the South Korean manufacturer and, so far, one of the best options for those seeking performance with aggressive timings combined to reasonably high frequencies. It is only surpassed by the more recent Hynix A-Die, which is capable of even higher clocks.
With DDR5, the DC-DC converter responsible for powering the memory modules has been moved from the motherboard PCB to the memory module itself. This move is intended to increase efficiency and minimize losses by placing the converter as close as possible to the load.
This converter is called PMIC and corresponds to an integrated circuit that does all this “dirty work”, where in the case of this DRAM kit, a unit from Renesas was adopted, which is compatible with the “High Voltage Mode”, that is, these memories can go beyond the 1.43V on VDD/VDDQ if the motherboard allow it.
Someone might be wondering: “But what’s wrong with these memories? So far, they seem to be a good option!”
The problem started right after the first post, as when attempting to activate XMP, there was only one profile available, “6000 40-40-40-80”, which is suspicious on its own as this was supposed to be a 6400 CL39 model.
Confirmation that there was indeed something wrong came when reading the SPD, which revealed that the “Part Number” of the modules is “JHE6000U4008JG” and the only XMP profile available was really the 6000 CL40 1.35V one.
“Ah, but that’s not such a serious problem, you can just set it manually…”
While this is technically true, in practice, the 6400 model is much more expensive than the 6000 model, with a difference of more than 20 USD per module. Therefore, it is possible to save a good amount of money by opting for the cheaper model, especially considering that they are identical in terms of specifications.
The idea behind getting a memory with higher frequency and more aggressive timings is that these kits usually use more carefully selected (binned) chips that can typically can do better on overclocking. Unfortunately, this turned out to be false for the JUHOR “6400” kit, which couldn’t even reach the results obtained by another Jazer 5600 kit, which also uses Hynix M-Die chips and is sold by the same company, the “ShenZhen Juhor Precision Technology”.
In this case, JUHOR only managed to complete the y-cruncher 1b @ 6400 MT/s after relaxing the tCL to 32 and reducing the voltage to around 1.41V, whereas the Jazer kit, which in theory should be inferior, achieves the same 6400 with CL30 and has no issues working with higher voltages, as was tested live in a livestream (in PT-BR).
In conclusion, it’s best to avoid these DIMMs because you’ll be paying a lot more for a DDR5-6000 module with a dishonest label on the heat spreader, where there is no advantage to this product, as even the chips are not of better quality compared to the Jazer DDR5-5600, for example.
If you’ve already purchased these memories, it’s worth taking a look at the “Part Number” recorded in the SPD. If it’s the same as the DDR5-6000, it’s recommended to file a dispute on AliExpress, attaching screenshots of the SPD and requesting a refund for the price difference between the two models since this is a typical case of being misled.