Introduction

I recently bought a Gigabyte GA-AB350M Gaming 3 together with a set of Kingston HyperX Fury 8GB DDR4-2666(1333MHz) memory sticks. Since I’m using Prime95 regularly to search for Mersenne primes, it seemed best to figure out how to overclock my memory to get better performance. This article describes the steps I took.

CPU-Z

You’ll need to install CPU-Z to use to verify your changes, and also give you an idea on expectations. By default the motherboard and BIOS should auto detect any DDR4 RAM you install and set the correct multiplier values.

After booting up my machine and then running CPU-Z and clicking the “SPD” tab, the below screenshot is what I get:

CPU-Z Speed tab

The SPD tab shows the manufacturer’s built-in speed specifications. A lot of things are shown here, including the part number. I’ve circled the “Max Bandwidth” value, as that tells us the details about the DDR4 RAM. In my case, the rated speed is 2666 MHz. Notice it shows 1333 MHz in brackets. This is because 2666 is the Double Data Rate(DDR), which is 1333 MHz X 2 = 2666 MHz. So double the frequency rate.

Hardware Monitor

We’ll also need some sort of hardware monitoring software for when stress tests are run, in order to verify the temperatures aren’t getting too hot. The CPUID HWMonitor tool works well for this purpose, except the “Temperatures” names are indicated as TMPIN0, TMPIN1, TMPIN2… I had a tough time figuring out what each of those values (6 temperatures) represent.

CPUID HWMonitor Screenshot

I would recommend also installing the Gigabyte Apps which have the “System Information Viewer”, also seen as “SIV” in the Apps. Below is a sample screenshot when you click click the “Hardware Monitor” icon in the top right of the SIV window:

SIV Screenshot

Based on looking at this and comparing to the TMPIN values in CPUID HWMonitor, these are what I determine the mapping to be:

TMPIN0 = System
TMPIN1 = Chipset
TMPIN2 = CPU
TMPIN3 = ???
TMPIN4 = VRM MOS
TMPIN5 = VSOC MOS

So I have no idea what the temperature TMPIN3 represents. If you happen to know, please let me know.

BIOS Settings

In order to overclock the Gigabyte GA-AB350M Gaming 3, you will need to reboot the machine and press the Delete key on startup (when you see the Gigabyte logo) to access the BIOS.

In the BIOS screen, all overclocking is done in the M.I.T. main menu. For my memory overclocking I made the following changes:

Extreme Memory Profile(X.M.P.) -->Profile1
System Memory Multiplier -->30.66

Advanced Voltage Settings
DRAM Voltage(CH A/B) --> 1.230V

Note: to change certain values, you need to use the Page Up and Page Down buttons on the keyboard to change them. This is not very intuitive, and you should keep this is mind when navigating the BIOS.

Checking Results

After saving the BIOS changes and restarting, make sure the PC boots properly. If it doesn’t, you’ll have to lower your speeds and/or voltage settings until it boots normally. Once your PC boots and you login, start up CPU-Z, then click on the Memory tab. For me, it looked like the following:

CPU-Z Memory

Notice the DRAM Frequency which is circled in red, which shows 1529.7 MHz; which is roughly half of 3066 MHz. So this is good.

Prime95 Tests

After making any overclocking changes, I highly suggest you download Prime95 and use the “Options > Torture Test…” and select “Blend“, then let this run for at least 6 hours to ensure stability of your system. Open up either CPUID HWMonitor or the Gigabyte SIV Hardware Monitor to constantly monitor your temperatures. You shouldn’t see anything get close to 100 °C, and if you do, you might need to either add more cooling or reduce your overclocking settings. Also if your PC crashes, or hangs or restarts, this is a sign that you’ve overclocked too much.

Enjoy, and happy computing!