What does it take to reach the top Intel Core CPU frequency at 7.328GHz?
You might think world records in the tech industry don’t make sense because you can’t reproduce them at home. But making a CPU run faster than anyone else is like trying to sprint 100 meters in less than 9.58 seconds, the current world record held by Usain Bolt, or drive a car at more than 1,227.98 km/h, the land speed record set by Andy Green. Every millisecond makes a difference. It takes weeks or even months just to prepare for an attempt, and you need the right gear and the right people to execute. Overclocking doesn't derogate from this rule.
Our recent Maximus IX Apex Absolute Zero event is the perfect example of what it takes to set records with silicon. Overclocker extraordinaire Roman Hartung, aka der8auer, has posted an excellent video detailing his experiences at the event, which produced eight world records including an incredible 7.328GHz for the Core i7-7700K. His perspective is embedded below, and we're also going to give you ours: a behind-the-scenes look at what it took to go beyond limits and reach new milestones in the tech industry.
Research and development
The Maximus IX Apex Absolute Zero event took place at the Republic of Gamers Headquarters in Taiwan. This is where all our research and development happens, where we search for innovations to make ROG products the best.
Months prior to the event, the engineers from our motherboard R&D department collaborated with the Product Manager to create something special for Intel's 7th Generation Core processors. Working in secret, they developed an all-new model for the Maximus line optimized specifically for overclocking. It was given unique features, like condensation detection for sub-zero operation, a two-DIMM layout capable of running dual-channel DDR4 at 4266MHz, pre-defined overclocking profiles contributed by experts, and advanced flow and temperature monitoring for water-cooling systems.
After hundreds and hundreds hours of testing, data collection, and adjustment, the Maximus IX Apex was finally ready. Next, it was time to prepare the hardware and other gear for the event.
The preparation
The key is getting everything to work together and finding the best settings and tweaks to squeeze more MHz from each processor. You might think all you need is a good CPU, but every single piece of hardware matters. The motherboard, graphics card(s), memory kit, PSU, and even monitor can make a difference for some benchmarks! If you're using Windows XP, a PS/2 keyboard and mouse are essential.
Cooling is essential, especially for extreme overclocking at sub-zero temperatures. You need an optimized copper pot on top of the CPU, efficient thermal paste to transfer heat away from the chip, and a good method for insulating other components.
Last but not least is the overclockers themselves. We invited the best in the world to the event, each one extremely knowledgeable and some with special skills like memory tweaking, temperature control, 2D or 3D benchmark tweaks, and good insight into the limits of the hardware.
Before the event began, our R&D engineers spent hours testing the hardware and squashing bugs to make sure everything was ready. The overclockers also got an early look at the Maximus IX Apex, so they could familiarize themselves with the board ahead of time.
Action
With nine overclockers, six days ahead of us (~70 hours), 1200L of liquid Nitrogen, 100L of liquid helium, and six systems set up, the event was ready to begin.
During the event, each overclocker focused on targets for key benchmarks. Sometimes they worked alone, but not for long. There were up to four people working on a single rig at times. Systems and benchmarks can be tricky, so you need to have multiple brains working together to find the small details that make the difference.
During the first five days, the overclockers only used liquid nitrogen (LN2) at -196°C to cool down their CPU, GPU, and memory. They mainly focused on 2D and legacy benchmarks. As each target score was reached, the overclockers focused on improving performance even more. We kept track of the progress on the leaderboard below.
On the last day, almost at the end of the day, the overclockers were ready to bench with liquid helium (LHe) that comes out of the tube at absolute zero, or -269°C. Liquid Helium is really difficult to handle; it needs perfect conditions and intimate knowledge of the system, so we waited until the last hours of the event. In the previous Z170 Absolute Zero event, the liquid-helium session didn’t work out well, mainly due to the cold bug of the Core i7-6700K CPU. The systems froze when temperatures dropped too low, requiring a restart.
Using ln2
To improve our chances this time, three systems were set up. der8auer and Xtreme Addict took the first one and targeted the maximum 4-core/8-thread CPU frequency, slamms took the second and concentrated on single-core frequency, and Dancop went for SuperPi 1M and PiFast on the third. Three overclockers were necessary just to handle the liquid helium. Coolice, elmor, and Shamino took care of the coolant, while Raja and fredyama followed what was happening on the screen.
First, the overclockers prepared their systems for an hour on liquid nitrogen. This phase was essential to make the machines stable and reduce temperatures gradually to avoid crashes. If one of the systems became unstable after the liquid helium started flowing, we passed it to another rig to maximize our time at absolute zero. The 100 liters of LHe on-hand only lasted about 20-30 minutes in total, but it gave us the additional 50-100MHz required to reach new milestones.
We watched the CPU frequency scale up, and it was very exciting to see der8auer and Xtreme Addict break 7.328GHz with all the i7-7700K's cores and threads active. Vlad set the best single-core Intel Core CPU frequency at 7.383GHz. You can see below the joy of the overclockers when reaching 4sec 985ms in SuperPi 1M. Their best score would be 4sec 937ms few minutes later.
Below is a summary of what we achieved using liquid helium. For more details about the scores and event, you can read the following article.
| Benchmark | WR - New Score | CPU frequency | Overclocker |
|---|---|---|---|
| CPU Frequency 1c/1t | 7.383GHz | 7383Mhz | slamms |
| CPU Frequency 4c/8t | 7.328GHz | 7328MHz | der8auer |
| PiFast | 8sec 720ms | 7272.07MHz | Dancop |
| SuperPi 1M | 4sec 937 ms | 7201.73MHz | Dancop |
