Let me start by saying we've all seen various extreme platforms over the years with small issues just after launch, X299 is no exception. However, things are not so bad as some make you believe they are. X299 actually offers a great platform if you need great multi-threading performance or just want to build a bad-ass gaming rig to maximize FPS. To enjoy X299 for all it has to offer, one needs to understand a few basics and some more detailed facts to properly build a rig, capable of harnessing such great power. This article will give you a few tips to set up your system and avoid unnecessary high VRM temperatures, power and throttling issues, which may occur when one of the building blocks of your rig isn’t up for the task.
"Hold your horses on picking a new motherboard, CPU and memory: Check your power supply first"
Tip #1: The power supply
Because X299, especially the 8-core and 10-core processors, are in need of plenty of power to deliver that great amount of multicore performance, it is key that you use a good quality power supply, capable of doing just that. Typically, an X299 build is capable of drawing at least 500W of power when the CPU is fully used with all 8 or 10 cores running at 4300MHz. However, because of X299 being fully unlocked without any brake on max. power draw, it is recommended to leave a little head room, especially if you are into adding performance by manual overclocking. When stress testing, especially when overclocked, wattages up to 300W are not uncommon. This means, if you have a proper cooling solution capable of handling this, a lot will be asked from your power supply, specifically putting a lot of power through the 8-pin CPU cables that come with it. Be sure to check the max. temperature of them, since they can run quite hot. Badly designed cables can result in dangerous temperatures; cases of 85°C 8-pin CPU cables have already been reported.
Properly designed ones (from most AAA brands) conduct current and heat well and will not suffer from this problem. From our own testing we listed a few models below which work perfectly on any MSI X299 motherboard:
"When you want to play with the big boys, do not cheap out on your cooling solution"
Tip #2: Keep your head cool (and your CPU)
You can imagine with all those high amounts of wattages mentioned when using all those 10 cores at full power, temperatures will also be pushed. It is not uncommon, when consuming 200 – 300W of sheer CPU power, core temperatures hit 80-95°C on the best AIO water-cooling units. When using an 8-core or 10-core CPU we therefor only recommend using high end water-cooling kits, more preferably using a custom water-cooling loop to fully enjoy the maximum performance for X299.
"One needs the right hardware to harness all that awesome power X299 has to offer, use the right motherboard to prevent performance throttling"
Tip #3: Pick the right motherboard with plenty of high quality power phases
Motherboard power design and the quality of the VRMs play an important role in handling the X299 CPU performance. Typically, to make good use of the 8-core and 10-core processors, a motherboard should come with 8+4pin or 8+8pin power connectors and plenty of premium quality power phases, to make sure the VRMs are able to deliver the desired power need to deliver extreme performance, without the possibility of being power starved, causing performance to be lowered due to throttling. Also make sure your motherboard has VRM heatsinks and you add a reasonable amount of airflow over your motherboard to ensure maximum performance during the longest gaming or overclocking sessions.
The X299 XPOWER GAMING AC comes with a 14-phase DrMOS power design with 8+4 pin CPU power connectors
Make sure you pick the right board when you are going for an 8-core or 10-core CPU. Especially if you fancy overclocking, the quality and quantity of the components and overall design of the board is very important to get stable results and acceptable CPU and VRM temperatures.
MSI X299 motherboards are designed to maximize performance and feature several performance enhancing hardware features
"Be thorough when testing for performance & stability: choose your software suite wisely"
Tip #4: Be wise when testing your settings, use the right software & methodology
Many people test stability using well known tools such as Prime95 or Linx. However, with the latest versions and inclusion of AVX2/AVX512, we found that these programs serve more and more unrealistic load scenarios than ever before, generating far more wattage and temperature than is needed to do stability testing.
Here is what happens if you run Prime95 on X299 on stock Turbo Boost 3.0 settings (tested on various motherboard brands and different CPUs)
Not really what we want and expect to see right? Things got even worse when we switched to different versions of Prime95, trying AVX2 and AVX-512. The CPU package wattage we see is totally out of proportion, causing the CPU to run very hot and starting to throttle. So really, for now, on X299 please use different stress testing tools to test your overclock. In a way, you could say that these tools are getting more like Furmark, but this time for CPUs. To preserve your hardware and avoid unnecessary torture we therefore suggest looking at other solutions for stability testing on X299.
For a quick test, Cinebench R15 is a good start to see if your CPU is performing on par, whether you are overclocking or not. However, the benchmark with Cinebench R15 is far too short for stability testing, as a continuous load is desired over several hours instead of seconds. So my suggestion would be to test the waters using Cinebench and if you think you’ve found a nice overclock with acceptable temperatures, start using other tools such as OCCT or Passmark for a realistic stability testing scenario. But don’t use Prime95, Linx or any other prime based benchmark as you would mostly be torturing your hardware beyond what is considered realistic usage.
Before testing, here are some BIOS settings tips for overclocking
Remove power limits, raise VCCin to at least 1.75v, find the lowest CPU vcore setting which is stable in order to lower CPU core temperatures and when successful, change the multiplier to 1 setting higher. So if 43x is successfully stable and you are satisfied with the maximum temperatures after stress testing (recommend not to go over 90°C), you can simply change 43x multiplier to 44x in order to achieve 4400 MHz. If 1.2v isn’t enough for these speeds, try adding half a mV so you test again at 1.25v. Once that is successful, you can start lowering the vcore again slightly to you find the lowest possible stable setting.
In order to check if your cooler is up to the task, here are some of our findings running the 7900X full 10 core / 20 threads through various benchmarks and stability tests. From stock to slightly overclocked, you can see the power draw just from the CPU:
Power draw i9-7900X - Default scenario 4.0 GHz on all cores, no OC.
Power draw i9-7900X – 4.3 GHz on all cores (auto vcore, average 1.208v), light OC.
For stress testing the use of OCCT standard setting in test CPU:OCCT is the best. It is really comparable to a real world load scenarios such as heavy multitasking/content creation and gaming.
When comparing a 1.5h test in OCCT to our Prime95 findings, the difference is a staggering 100W less CPU load in OCCT, no CPU throttling and not so dangerous CPU core temperatures. (Even though this is really the limit of our AIO cooler used, Nepton 140 push/pull).
So we have 4.3 GHz completely stable, now let’s move to 4.5 GHz using a more premium AIO watercooling solution. Here you can see me test out 4.5 GHz. Although a couple of runs with Cinebench were stable, the AIO cooler simply wasn’t able to cool down the CPU well enough for a few hours of stress testing, reaching almost 100°C, which is unacceptable and dangerous for longer periods of time.
I don't give up easy; So I mounted my Phase Change unit for some proper subzero overclocking. Here is a short video of a Core i9-7900X running @ 5.0GHz 1.35v 10cores/20threads Cinebench stable without throttling. The score of 2703cb is in line with the CPU frequency being increased when compared to stock scores, so we can see there is no throttling going on here.
It's even capable of running 5.0 GHz using the auto-overclock feature Game Boost Needless to say, you really need your cooling to be in order to run these kinds of speeds.
As I use a custom watercooling setup for my 24/7 rig, I didn’t do stability testing for this overlock, as it’s mostly for benchmarking purposes, but now you know it can be run while keeping the temperatures in check. Even though my LD PC-V2 Phase Change is modded and can cool up to ~330W CPU power while retaining -30°C under that load, we still see the CPU package and core temperatures in the +30°C while benchmarking, but this is due to another reason, which I will explain at the end of this article.
Tip #5: Spend time on getting to know your setup
A lot of times people expect wonders from hardware by fiddling it for 5 minutes, if they don’t see their expected result after that then often people tend to say: “I was disappointed by it..” or similar remarks. However, with all the power X299 and these high core counts have to offer, it is more important than ever to spend more time to get to know your setup and fine-tune the settings to get the most out of it. If you are a PC enthusiast, one might even say it is enjoyable to keep pushing the limit ;)
For reference, we’ve written down 3 possible scenarios on what you can expect running stable, with acceptable temperatures, when using the 7900X 10-core CPU and different cooling setups:
1. Stock/slight overclocked setup using an A-grade AIO watercooling solution: 4.0 – 4.3 GHz on all 10 cores. This will make the CPU consume ~220W of power while stress testing.
2. Moderate OC setup using a custom watercooling loop: 4-3 GHz – 4.5 GHz on all 10 cores. You can expect the CPU to consume around 270W of power when stressing it.
3. Heavy OC setup using subzero solutions (Phase Change/Cascade/Dry ice/LN2/etc.): 4.5 – 6.0 GHz depending on the extreme cooling solution used. However, for reaching for a 5.0 GHz OC and beyond, it is almost mandatory to delid any Skylake-X CPU. This since the cores are unable to get the heat dissipated due to the CPU heatspreader (IHS) being glued to the to CPU cores (DIE) and unable to transfer internal heat efficiently to the heatspreader (as opposed to being soldered, which is way better to get rid of heat). So even when using extreme cooling, the temperatures underneath the heatspreader still run too high. By delidding and replacing the stock paste between the CPU DIE and heatspreader with other solutions such as Liquid metal or other A-grade thermal paste such as MX-4 or Thermal Grizzly, or even running it with directDIE cooling (with the heatspreader removed altogether) will heavily reduce CPU core and package temperatures, extending the range of overclock capabilities of X299 Skylake-X significantly.
So with these tips I hope you are able to enjoy X299 even more and reach new heights pushing the limits even further. Speaking of pushing limits, MSI X299 motherboards are all designed for you to enjoy the maximum performance from the Skylake-X and Kabylake-X processors. In case you own X299 but didn’t try overclocking yet or are thinking of upgrading, why not try it for yourself and let us know how you did? You can find more information about our X299 motherboards here