Is CPU Overclocking in Solidworks 2017 worth it? (i7-7700K)

Introduction

We want to be clear that here at Puget Systems we do not encourage overclocking except in very specific situations. We value reliability in our workstations above almost everything else and even a modest overclock will put your system at a higher risk of problems than a non overclocked system. That isn't to say that every overclock will fail or every stock CPU won't, but any time you run a product beyond what the hardware manufacturer has qualified you are running a risk.

With our general bias clearly stated, the purpose of this article is to examine the performance effect of overclocking in SOLIDWORKS 2017 to determine if there is a significant enough performance advantage to outweigh the associated risks. If you want to skip over our individual benchmark results and simply view our conclusions, feel free to jump ahead to the conclusion section.

Test Setup

For our test system, we used the following hardware:

This system is essentially a larger version of our Recommended System for SOLIDWORKS with the space necessary to accommodate the closed-loop liquid cooler needed to overclock the CPU. At the time of this article, the Intel Core i7 7700K is a very new CPU and a "safe" overclock range has not yet been nailed down. So to cover our bases, we are going to test with a range of overclocks spanning from a small 100MHz gain (4.6GHz) to a 500MHz gain (5.0GHz).

To make sure our results are as consistent as possible we used a combination of SOLIDWORKS macros and a custom script using AutoIt to start SOLIDWORKS, load the relevant test file, then time how long it takes to perform the various task we want to benchmark. To perform the actual testing, we used a mix of SOLIDWORKS training files and files available from GrabCad.com. These files and the associated test are:

Startup Time

To start off our testing, we simply timed how long it took for SOLIDWORKS to start. One thing to keep in mind is that the smallest unit of measurement we are using is a tenth of a second and since it only takes SOLIDWORKS about 5 seconds to start, that does mean that there is a pretty wide margin of error. With a 4.7-4.8GHz overclock (which right now appears to be reasonably safe) you are looking at about a 6-7% improvement in the time it takes SOLIDWORKS to launch. This is less than half a second, however, so it is unlikely to be noticeable in the real world.

File Open & Save

Opening and saving files is often a pain point for SOLIDWORKS users so it is something we specifically wanted to test. While the files we used to test don't take an hour to open and save, they take long enough that we can get a good idea of how much overclocking can help. Starting with the time it takes to open files, we saw a decent increase in performance with overclocking. Averaging both the drawing and assembly results, we saw a 5.5-8.2% decrease in the time it took to open with an overclock  of 4.7-4.8GHz.

For saving files, the performance gains with overclocking are very similar. There isn't quite as good of an improvement with the higher overclocks, but a decent 4.7-4.8GHz overclock gave a 5.6-7.5% improvement.

Rebuild

Rebuilding our assembly took a fair amount of time, so we managed to save several seconds with overclocking. Again focusing on the 4.7 and 4.8GHz overclocks, we saved about 7 and 9.5 seconds respectively. In terms of percentages, it is almost identical to what we have seen in the previous sections: 5.2-7.1%.

Motion Study

Our motion study benchmark consists of a 10 second, 60 FPS animation. With a 4.7GHz overclock, it took .9 seconds less time to complete the calculations resulting in just under a 5% improvement in performance. With a 4.8GHz overclock, we saved 1.3 seconds which works out to be a 6.9% improvement in performance.

FEA and Flow Simulation

Simulations can often take a long time, so any time savings here will likely be more significant than some of the previous sections. In this case, we found that a 4.7-4.8GHz overclock should improve performance by around 4.7-5.5% on average. Interestingly, this is actually a bit lower than what we have seen in the previous sections so overclocking appears to not be quite as effective for simulations.

Rendering

In SOLIDWORKS, rendering is divided into two steps: an irradiance pre-pass and the final render. The irradiance pre-pass typically only takes between 15-30% of the total render time, but for large renders that can still be a significant amount of time. Combining these two steps, we saw a 5.1% improvement with a 4.7GHz overclock and a 7.9% improvement with a 4.8GHz overclock. For our test this only works out to 8.4-12.7 second difference, but for longer renders this can certainly add up over time.

Model Rotation

The FPS you can achieve when rotating a model is going to be heavily dependent on the complexity of the model, the quality settings you use, and the resolution of your display. For this test, we chose to use a fairly complex model as it gives us right around 60 FPS when using the toughest display settings. A less complex model may show a different result between the two overclocks, but if you are already getting >100 FPS, even a 10% improvement doesn't really mean anything since the FPS is already much higher than the human eye can detect or that most monitors can display. 

With a 4.7-4.8GHz overclock, we saw anywhere from a 2.4 to 7 FPS improvement. This isn't huge (about 5.6-7.8%) but it is perfectly in line with what we have seen in the previous sections.

How much time will overclocking save you?

If you looked through the individual results, you likely noticed that the percent improvement we saw with overclocking was very consistent. Due to this, we are comfortable presenting an average overall performance gain chart:

Obviously the performance gains change depending on how far you push the overclock, but we would consider around a 4.7-4.8GHz to be reasonably safe – or at least, as safe as overclocking can be. At that amount of overclock, you can expect roughly a 5.9-7.9% improvement in performance in SOLIDWORKS.

This doesn't mean you will magically be able to get all of your work done 6-8% faster, but it does mean that any task you have to sit and wait on should be able to complete a bit quicker. If you wanted to determine how much time you would save with an overclocked CPU, a very broad way to do so would be to estimate the amount of time you spend per day waiting for a task in SOLIDWORKS to finish then apply the above results to determine how much time you would save. Looking at just what we expect to be in the "safe" range overclocks (if overclocking in general could be called safe), we came up with the following time savings depending on how long you wait on SOLIDWORKS:

Using the chart above, we can estimate that if you spend 5% of your day (about 24 minutes) waiting for something in SOLIDWORKS to finish, you could save about 1.5-2 minutes a day by overclocking a 7700K to 4.7-4.8GHz. If you spend 20% of your day (about an hour and a half) sitting watching SOLDIWORKS process a task, you could save yourself about 5.6-7.5 minutes a day.

Time saved is time saved and it is up to you if saving a few minutes a day is worth the risks associated with overclocking. No matter the precautions you take, overclocking is always going to carry with it some amount of risk so while saving time is nice you also need to consider the downsides associated with overclocking.

Risks of overclocking

There are a number of risks associated with overclocking, but in our opinion the big six are:

1. System rebooting unexpectedly
2. Bluescreens
3. Failure to boot/POST
4. Data corruption
5. Inaccurate calculations
6. Premature failure of components

Out of all the above, the first two are the most common. In the case of a unexpected reboot or bluescreen, you should (hopefully) only lose the work you performed since the last time you saved. If the system is in the middle of a large simulation or render, however, the time lost could be anywhere from minutes to hours to even days. Even if this only happens a few times a year, that may completely offset any time savings gained from overclocking.

Number three on the list – failure to boot/POST – is less common but still happens more often on an overclocked system. The majority of the time, this issue can be resolved by clearing the CMOS (to remove the overclock), then re-applying the BIOS settings. If you are not comfortable doing this yourself, this would result in the machine being un-usable until either your IT staff can work on it or you can send it in for repair which can take at minimum 3-7 days depending on the shipping method. And if the issue turns out to be more than just a simple CMOS clear the repair time could easily turn into 1-2 weeks depending on the nature and extent of the issue.

Worse than just failure to boot is if an unexpected reboot or a bluescreen corrupts your OS. In that case, you are likely looking at having to restore the OS to a previous state or perform a complete re-installation of the OS. This can take a significant amount of time depending on whether you can do it yourself or if you need to ship the machine in for repair.

Possibly the worst risk associated with overclocking is the small chance of inaccurate calculations. A small inaccurate calculation is likely not a huge problem for many tasks but if you are doing a simulation (such as simulating the stresses on the brake pads of a car), a single wrong calculation can potentially have drastic consequences.

Lastly, since you are running the system beyond the manufacturer's specifications, you run the risk of one or more components failing sooner than they would otherwise. If you refresh your hardware every year or two this likely isn't an issue, but if you want to get as much life out of a system as possible overclocking is not a good way to do so. In addition, overclocking will usually void manufacturer warranties which mean any part failures may not be covered by the OEM. If you purchase a system with overclocking included, a failed CPU should be covered by the system builder's warranty – but if you are outside the system builder's warranty and the CPU fails, you will not be able to rely on Intel/AMD's warranty to replace the CPU.

To be completely fair, as long as the overclock isn't too extreme, the system has adequate cooling, and high quality components are used, these issues shouldn't come up too often. What it really comes down to is a gamble: you are wagering saving a few minutes per day against the chance of your machine possibly being out of commission for several days at a random time in the future.

Conclusion

We expect some of our readers will have strong opinions on this subject, so we encourage you to leave your comments below. Do you think the time savings is worth overclocking your CPU, or are the risks simply not worth it?