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ROGBot
Users have been getting mixed results with getting their DDR4-3000 kits to work on the Rampage V Extreme. In theory, the setup process is quite straightforward. You enable the XMP profile in the BIOS and let the motherboard do the rest of the hard work. So why isn’t everyone getting the same results?
A Quick Explanation Of The Issue
The motherboard automatically assigns values to the different voltages for your CPU. Normally these values are on the Auto setting which means that they will scale accordingly when you enable the XMP profile for your RAM. ASUS sampled hundreds of CPUs to determine the scaling routines for the Rampage V Extreme. So unless you have a below average CPU, the Auto value is pretty much spot on.
The timings and the DRAM voltage for your memory kit is dictated by the XMP profile. But the motherboard also adjusts other memory related voltages as well. One of the more useful voltages for memory overclocking is the System Agent Voltage (also known as VCCSA on previous platforms). The System Agent Voltage is responsible for stabilizing the CPU’s integrated memory controller (IMC) to help you run memory with high frequencies.
Your memory goes through training at each system post. If your memory fails training because of insufficient System Agent Voltage, your system will halt with a bd QCODE visible on the Rampage V Extreme’s DEBUG LED.
The Kit Used In This Guide
I chose this G.Skill Ripjaws 4 F4-3000C15Q-16GRR kit mainly because of its excellent price/performance ratio. It’s currently one of the more popular DDR4-3000 kits in the market right now and most enthusiasts are rolling with this particular kit in their X99 systems. It’s comprised of four 4GB sticks rated at 3000MHz with 15-15-15-35 2N timings using 1.35V.
Preparations
At the time this guide was written, the latest BIOS was 0802. It’s highly recommended that you update your Rampage V Extreme to the 1801 BIOS since compatibility with XMP profiles and memory overclocking has been greatly improved. Many users were able to get their DDR4-3000 kit working on this BIOS without the need to tune the System Agent Voltage manually. But if it doesn’t work for you, continue on.
Since we’ll be focusing solely on the System Agent Voltage, we’ll add it to the My Favorites tab so we can get quick access to the option instead of scrolling all the way down the Extreme Tweaker tab to find it. So first we’ll open up the My Favorites tab.
Once inside, we’re going to select the Extreme Tweak option on the left and scroll down to find the CPU System Agent Voltage.
Click the + symbol beside the CPU System Agent Voltage to add it to the right column.
Methodology
This guide will assume you’ve enabled your XMP and restarted your system. Once your system hangs at the bd QCODE, there isn’t much you can do. Even if you hit the Power, Reset or the ReTry button your system will simply restart and halt at the same QCODE as before. While most users turn to the Clear CMOS button at the rear panel to reset the BIOS values back to factory default, we’re going to take a different approach.
If you closely at the overclocking area, you will notice the little red button called Safe Boot. Pressing it will force the motherboard to reboot into the BIOS safe mode retaining all the previous settings that were changed.
Once inside the BIOS, we’ll navigate back to the My Favorites tab. The System Agent Voltage is a sensitive voltage. Too much or too little voltage can lead to instability. The best approach is to use increments of 0.01V to find the sweet spot for your CPU.
One of two things can happen at this stage.
- If your system fails to post again, keep tuning the System Agent Voltage until you make your way into your OS.
- If your system posted successfully and you’re able to enter your OS, proceed to the next phase.
Quick Stability Test
SuperPi provides a quick way to test the stability of your memory. The 32M preset relies heavily on memory access so that’s what we’ll choose. A typical run should take around 9 minutes on a stock i7-5960X.
Should you encounter any signs of instability during the 32M test like BSODs, system freeze or SuperPi errors, go back into the BIOS and raise the System Agent Voltage another notch. Once you’re able to complete the 32M test, it’s time to do some memory stress tests.
Long-term Stability Test
HCI MemTest is one of the best programs to find immediate and long term memory errors if any are present. Since it’s a single threaded program, it’s recommended to run as many instances of MemTest as you have CPU threads to increase the program’s effectiveness.
On my i7-5960X, I’m running 16 instances to test my memory thoroughly. Since it’s time consuming to open each instance one by one, I’ve written a simple Batch file to open all of them with a single click. The only requirement is that the batch file must be in the same directory as the memtest.exe. For the other Haswell-E owners, you can edit the batch file in Notepad and erase the number of instances to match your CPU cores. Once you have your instances ready, open Task Manager. Look at the amount of unused memory available and divide it by the number of instances. The result will be the amount of memory you will type in the each MemTest window.
Memtest is designed to run as long as you wish. But for an everyday system, four full passes (400% coverage) should be more than enough. But if memory stability is vital for your system, you can let it run overnight. If any errors show up, continue tuning the System Agent Voltage.
Just a reminder. Memory, when stressed just like any other component, will generate more heat than normal usage. So if your plan is to test your memory for prolonged periods of time, it is wise to put some sort of active cooling over the modules. It doesn’t have to be one of those crazy Delta fans that sound like jet engines. Any 120mm fan will get the job done.
And to finalize this guide, here’s a screenshot of my i7-5960X finishing 4 full passes of MemTest. It’s not a good sample and needs a System Agent Voltage of 1.14V to run memory at 3000MHz. It’s been running for a few months now and there are no negative side effects of running at that voltage.
There is no official word from Intel concerning the maximum safe System Agent Voltage so I cannot give you a number to go by. They used to put that information into their data sheets but they stopped doing so ever since Haswell came out. Currently the Rampage V Extreme has one of the most mature BIOS found on any X99 motherboard plus it has the OC Socket which certainly gives it the upperhand when it comes to memory overclocking. So you’ll find that you need less voltage than rival motherboards.
Chino wrote:
They might not work at the rated speed without manual tweaking.
Thanks for the reply, that im not to happy about 🙂
Another question:
I have been told by a friend of mine, that if i install the 2nd set of Ram in the "black color slots" and keep the first set in the "red color slots" and never mix them, it should not be a problem at all.
Is there any truth in that?
(damn, i remember the old days where you just throw every ram block you could get your hands on, in the machine. Now it's nearly rocket science) ...for me 😉
