32GB in a single slot, How?
While the JEDEC Solid State Technology Association, the organization that develops and defines open standards such as DDR4, allows up to 64GB per DDR4 module, the practical limit has been 16GB per module for consumer-oriented U-DIMMs.
ZADAK has teamed up with ASUS to bend the rules and enable users of a few ASUS Z390 based board to break the 32GB limit on compact systems limited to 2 DIMM slots and enable these high-performance machines to utilize a full 64GB.
Currently, the supported systems ready to work with Double-Capacity Memory are the ASUS ROG Maximus XI Gene, ASUS ROG Maximus XI Apex, and the ASUS ROG STRIX Z390-I Gaming which is what we will be testing with today.
When we first boot the system up and enter BIOS, we see something a little funny. We have two sticks of memory installed, one in each of the two available slots. Notice anything above? Yup, it’s showing as FOUR 16GB modules. When we tested this board previously with ‘normal’ memory, only DIMM_A1 and DIMM_B1 were visible here.
We took this picture before installing a CPU and putting it on the test bench, but yes, that’s only two memory slots.
ASUS’s SPD tool in the BIOS again shows four slots, with a 16GB module in each. All 64GB (65,536MB) shows correctly in the hardware monitor in the right pane.
Let’s go ahead and kick on XMP while we are here which brings us to 3200MHz effective at tight 14-16-16-36 Timings.
Once we get to Windows, CPU-Z shows all full compliment of 64GB, again spread over 4 slots with 16GB each.
It might be an interesting way to go about it, but the simple fact is, ASUS and ZADAK did it. 64GB of memory on an ITX system gives you serious power in a small space.
We had the ASUS ROG Maximus XI Extreme on hand, and with ZADAK being nice enough to send us a whopping 128GB of the new Shield DC, we just HAD to try it on an ‘unsupported’ board.
It does look amazing in a bank of four modules, doesn’t it?
Unfortunately, this unsupported board is indeed unsupported. It refuses to even POST and throws a memory detect code. We also tried on ASUS’s other Z390 board, the ROG Maximus XI Hero WiFi, but it also would not even POST with any of these installed. We had to try, but now you know. 128GB on a 9900K… is still just a dream for now.