The Haswell-E platform and DDR4 standard opened up a door to new possibilities in regards to memory capacity. With the availability of high-performance X99 motherboards with 8 memory slots and 16GB memory modules, we find ourselves at the threshold of the 128GB era. Previously it was only possible to find support for memory at that capacity in workstations and servers. Those usually cost an arm and a leg. Kudos goes to Intel for bringing us the first consumer platform to support memory capacities up to 128GB.
Most of us can agree on the fact that general PC users, gamers and enthusiasts can get by with 8GB or 16GB. Professional users who rely on heavy memory programs and virtualization will certainly welcome the possibility to have more memory. Running 128GB of high speed DDR4 isn’t a simple task so plug-n-play shouldn’t be expected. Manual tweaking is required to achieve stability.
HyperX Savage DDR4 128GB (8 x 16GB) DDR4 2666
The 128GB memory kit featured in this setup comes from the HyperX Savage DDR4 line with model number HX426C15SBK8/128. It is comprised of eight 16GB DIMMS with a speed rating of 2666MHz and a voltage of 1.2V. The kit is available at Newegg for $607.99.
Motherboard BIOS
Support for the 128GB capacity was added through a BIOS update for the X99 motherboards. Luckily we can find out what shipping BIOS came with our motherboard without having to power it up.
Locate the long, thin sticker that contains a barcode and a bunch of numbers. The last 4 digits is the shipping BIOS for the motherboard we have in our hands. Depending on the model, this sticker can be found above the memory slots, beside the 24 pin power connector or on the side of one of the PCIe expansion slots.
The following table lists the different ASUS X99 motherboards that are capable of running 128GB of RAM and the minimum BIOS revision necessary. If your shipping BIOS is prior to the revision listed in the table, proceed to the USB BIOS Flashback section.
| Motherboard | BIOS |
| RAMPAGE V EXTREME | 1502 |
| SABERTOOTH X99 | 1801 |
| X99-PRO | 1801 |
| X99-A | 1801 |
| X99-DELUXE | 1801 |
| X99-E WS | 1201 |
| X99-S | 1801 |
USB BIOS Flashback
USB BIOS Flashback is a nifty feature to update your BIOS using a USB pendrive without a CPU or memory module present on the motherboard. The only requisite is that the motherboard must be receiving power.
However, here are some recommendations for the USB pendrive:
- Make sure the USB pendrive is FAT32 formatted.
- The USB pendrive should be empty.
- When possible, use USB pendrives that are small in capacity (2GB, 4GB or 8GB).
- Avoid using USB pendrives with hidden partitions.
Here’s the common procedure for using the USB BIOS Flashback feature:
- Download the latest BIOS along with the BIOS Renamer from the motherboard’s support page.
- Extract both to the same folder.
- Run the BIOS Renamer to have the BIOS file renamed automatically for the USB BIOS Flashback procedure.
- Copy the BIOS file to the USB pendrive.
- Insert the USB pendrive into the dedicated USB BIOS Flashback port.
- Press the USB BIOS Flashback button for three seconds until a LED starts to blink, then release the button.
- The LED will eventually blink faster and faster. Once it stops blinking, the process is finished.
Memory Tweaking
Configuring a 128GB memory kit to play nice on your motherboard requires a certain level of patience since a lot of trial and error takes place. Luckily, Rampage V Extreme owners can make use of the Safe Boot button that is located just right beside the Slow Mode Switch at the edge of the motherboard. The Safe Boot button forces the motherboard to reboot into the BIOS safe mode retaining all the previous settings that were changed.
Since each CPU is different, there isn’t a magic setting or a one configuration fits all. There are certain settings that can help us achieve stability. So it’s beneficial to add these settings in the My Favorites tab so we don’t waste time finding them one by one later on.
The QCODEs that pop up during post is a good indication which voltages to modify. A bd QCODE usually indicate insufficient System Agent Voltage. But since it’s a sensitive voltage, I don’t recommend you brute forcing it but rather use small increments.
A bf QCODE is a little tricky since it’s a memory instability error. As a starting point, change the Rampage Tweak option from Auto to Mode 1. If that fails, continue in Mode 1 and slightly increase the CPU Input Voltage, Core Voltage and Cache Voltage by a little bit. Some users increase the DRAM voltage but personally I don’t go that route. If none of the above works, then one must settle that his CPU’s IMC is below par and it might be necessary to consider running the memory at a lower frequency or with loosened primary timings.
Google Stressapptest
Stressful Application Test (or stressapptest, its unix name) is a memory interface test. It tries to maximize randomized traffic to memory from processor and I/O, with the intent of creating a realistic high load situation in order to test the existing hardware devices in a computer. It has been used at Google for some time and now it is available under the apache 2.0 license.
In order to use stressapptest, it is necessary to install Linux. Linux Mint Cinnamon is one of the best and most popular distro for desktops. Nevertheless, you can use whichever distro you’re most comfortable with. We will need to download the 64-Bit ISO and UNetbootin to create a bootable USB pendrive.
Once we’ve downloaded both files, run UNetbootin as administrator. Choose the Distribution you’re using and point the program to the ISO you’ve downloaded. The 64-bit version of Linux Mint is particularly small (less than 2GB) so a 4GB USB pendrive is more than sufficient.
Once the process has finished, restart your system and boot from the USB pendrive. You will be greeted with the following Linux Mint desktop. At this point you can continue to run the OS from the USB pendrive or install it to a spare HDD/SDD. If you prefer to run it off the USB pendrive, skip the following steps.
Double click the Install Linux Mint shortcut to start installation to a HDD/SSD. The install process is straightforward and identical to a Windows installation so you shouldn’t experience any problems with it.
Once the installation is over or if you skipped to this step, the next step is to download the Google Stressapptest. The quickest way to do so is to open up a Terminal and type the following command:
If done correctly, the application will download on its own and install itself automatically.
To run our newly installed stressapptest, we will input the following command:
The duration of the test is measured in seconds. As a minimum, I would recommend you run at least 1 hour. As always if memory stability is a matter of life or death for your system, you should run it for a longer duration. There should be 0 errors during the test. If any errors show up, stop the test and continue tweaking the various voltages and rerun the test.
I was able to overclock the HyperX Savage DDR4 kit from 2666MHz to 2800MHz since my 5960X’s IMC is average at best and seems to top out at 2800MHz when using 128GB. The kit is running with the exact timings except for DRAM voltage which was raised to 1.35V to accommodate for the overclock. In regards to the other settings, everything was on Auto except for the System Agent Voltage which I increased to 0.95V and the CPU Input Voltage to 1.9V.
Chino,
Very good guide, especially like the well explained Linux guide
Very good guide, especially like the well explained Linux guide
