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Introduction
CUDIMM, or Clocked Unbuffered Dual In-Line Memory Module, is a variety of DDR5 memory that integrates a clock driver (CKD) chip directly onto the memory module itself. This enables the electrical signal to be improved, thus allowing the memory modules to attain very high memory speeds, Mega Transfers per Second (MT/s) at stable frequencies. We’ve got one such memory kit to review today, the G.SKILL Trident Z5 CK RGB DDR5-8400 CL40-52-52-134 1.40V 48GB (2x24GB) memory kit. That is G.SKILL’s high-end offering in its Trident Z5 CU-DIMM series.
In G.SKILL’s memory lineup, it offers each traditional DDR5 U-DIMM memory modules and the brand new DDR5 CU-DIMM modules. G.SKILL has a plethora of well-known series of DDR5 RAM, with probably two of essentially the most well-known series within the flagship Trident series and the Ripjaws series. Among the many Trident series are sub-series of memory modules, similar to the Z5 CK RGB and Z5 CK (the CUDIMMs we’re reviewing today), Z5 Royal, Z5 Royal Neo, Z5 Neo, and Z5. These different series have some with RGB, and a few without, and vary in heatsink color and magnificence. As you’ll imagine, the Z5 CK RGB specifies using a CKD chip to inform you that these are CUDIMM memory modules. For those who want the non-CUDIMM, i.e. U-DIMM, the opposite Z5 models below this are UDIMM versions.
It also needs to be noted that certain models are geared more for Intel/XMP, while others are geared for AMD EXPO. The Trident Z5 CK RGB and Z5 CK are made for Intel Z890 motherboards and Intel Core Ultra CPUs, as they support CUDIMM memory modules and high-speed DDR5. The Trident Z5 Royal can be meant for Intel/XMP. The Z5 Royal Neo and Neo are geared for AMD EXPO speeds, while Z5 is Intel/XMP. After all, you’ll be able to run XMP profiles on EXPO motherboards, but you’ll be able to’t run CUDIMM’s yet on AMD motherboards, and high frequency isn’t guaranteed.
Under the Trident Z5 CK RGB (DDR5/Intel XMP) category on G.SKILL’s product page, there are five kits offered at different speeds. Note that every one five kits are of the 48GB (2x24GB) capability configuration, and all are CU-DIMM memory. The speeds offered are 8200MT/s (CL40-52-52-131), 8400MT/s (CL40-52-52-134), 8800MT/s (CL42-55-55-140), 9000MT/s (CL42-56-56-144) and even 9600MT/s (CL46-58-58-153) memory. All memory kits have the identical design, with RGB. The memory kit we’re reviewing is: F5-8400C4052G24GX2-TZ5CRK.
G.SKILL Trident Z5 CK RGB DDR5-8400 48GB
The G.SKILL Trident Z5 CK RGB DDR5 8400MT/s CUDIMM 48GB memory series is G.SKILL’s flagship CU-DIMM DDR5 memory series with a glossy piano black heatspreader and RGB. G.SKILL claims hand-selected memory IC’s and that this memory is built for overclockers and enthusiasts. It’s designed for Intel Core Ultra 200K series desktop CPUs and Z890 chipset motherboards.
The memory is DDR5 in a dual-channel kit and supports Intel XMP 3.0. It runs at 8400MT/s in Profile 1 XMP mode and has timings set at CL40-52-52-134 in Profile 1. It runs at an XMP voltage of 1.40V in an Unbuffered format Non-ECC. Its default SPD Speed is 6400MT/s on Intel Core Ultra CPUs (non-Plus series). The SPD Voltage is 1.10V. G.SKILL has a QVL list and links on its website.
XMP Memory Profiles
Inside this memory, there are two built-in XMP profiles, Profile 1 and Profile 2.
In XMP Profile 1, the memory runs at 8400MT/s CL40-52-52-134, and in Profile 2, it runs at 6400MT/s CL32-39-39-102. Profile 2 is essentially a faster timing SPD or default memory frequency mode. For instance, within the default (no XMP profile chosen) mode, it runs at 6400MT/s CL52-51-51-102. Subsequently, Profile 2 offers a much faster 6400MT/s default mode that sets the RAM right down to much tighter and faster timings.
Within the screenshots above, you’ll be able to see the primary screen at Default 6400MT/s with no profile chosen, then within the second screenshot, XMP Profile 2 is enabled at 6400MT/s with faster timings. Finally, the third screenshot shows XMP Profile 1 enabled on the overclocked 8400MT/s CL40 setting.
For a better take a look at the timings supported at lower frequencies, you’ll be able to see those listed here on this screenshot above for this memory kit.
Overclocking
For our overclock testing, we simply tried to push it up so far as possible without changing the Voltage or any power settings in any respect, by simply raising the frequency within the BIOS. In doing this, we were easily capable of take this RAM as much as DDR5 8800MT/s at only barely higher timings, CL42-55-55-141. It was as easy as upping to DDR5 8800 within the motherboard BIOS, and this RAM just worked, with no issues, and without having to boost the Voltage.
It is feasible it could run higher, with looser timings, and potentially higher with tighter timings when adding Voltage or tweaking power settings. This RAM seems quite able to being highly tweaked by enthusiasts and overclockers; it’s, in any case, built for it. For our overclocking today, we’ll go together with this stable, no-voltage-added overclock in our benchmarks just to point out it above the built-in Profile.