eGPU performance greatly depends on how Thundebolt 3 is integrated into the system. With the release of Ice Lake CPUs and the improvements that architecture brings, I wanted to see if there was a performance improvement for the eGPU crowd.
Let's get started on this comparison between an 8th-gen Coffee Lake CPU and the current 10th-gen Ice Lake CPU.
Setup
Ice Lake Laptop – Late 2019 Razer Blade Stealth – Intel i7 1065G7
Coffee Lake Laptop – Early 2019 MSI GS65 - Intel i7 8750H
eGPU Enclosure – Razer Core X Chroma
GPU – MSI 1080 Ti Gaming X
OS - Windows 10 Pro 1903
Nvidia Driver - 441.20
Technical stuff
For an introduction to eGPU and Thunderbolt, click HERE.
Ice Lake is special to Thunderbolt because it directly integrates the controller into the CPU die. Other CPUs like Intel 8th Gen and Intel 9th Gen (Coffee Lake), and even 10th Gen (Comet Lake) don’t have this integration and must use an external controller built into the motherboard called Titan Ridge.
To better digest this information, Ice Lake CPUs remove the “middleman” by integrating Thunderbolt while the other CPUs rely on the middleman to pass the information. A more direct connection can result in better performance.
Variables
There are 2 main variables to this comparison outside of Thunderbolt integration:
CPU Core Count:
Ice Lake is a 4-core, 8-thread CPU. Coffee Lake is a 6-core, 12-thread CPU. That’s already a 50% advantage in core count for Coffee Lake.
CPU Speed:
Ice Lake has a All-Core turbo speed of 3.5GHz but it actually throttles as low at 2GHz due to a TDP (Thermal Design Power Limit) of 15W. It can boost up to 3.5GHz at 15W but it depends on how CPU-intensive the game or application is. In my testing, I tried my best to tweak settings to reduce throttling and got the CPU to throttle to 2.2GHz at 15W. Since it was a review unit I was testing, I didn’t want to risk bricking the system by flashing a modified BIOS which would remove throttling. As an FYI, it can be configured up to 25W, my machine came with a 15W version.
The Coffee Lake CPU is rated at 45W and has a All-Core Turbo speed of 3.9GHz. That clock speed is ROCK SOLID due to some BIOS modifications I made. Basically, I made the machine think it’s using less watts and amps so the CPU NEVER throttles. I own this machine so I modified everything I could find to reach this level of performance.
On paper, this already looks like an unfair comparison. Not only does the Coffee Lake CPU have 50% more cores, it sustains its turbo speeds with no issues. Let’s see how much of a difference on-die Thunderbolt integration will have for performance.
Performance
Before we get into performance, I'll talk about how I installed my drivers.
Below is the process I went through to get eGPU to work flawlessly and without breaking Optimus:
Download the latest driver from Nvidia HERE. It doesn’t matter if the laptop GPU is a GTX and the desktop GPU is an RTX, it’ll install the same. Just choose either 64-bit/32-bit and standard/DCH drivers.
Download Display Driver Uninstall Utility from Guru3D.com HERE.
Download CCleaner Free HERE.
Download NVSlimmer HERE.
Go into airplane mode. This ensures drivers are not downloaded and installed by windows update once the old drivers are uninstalled
Uninstall your Nvidia driver in “Apps and Programs”. Do NOT reboot.
Run DDU in Safe Mode (Now you will have to restart in Safe Mode). Uninstall the Nvidia Driver again. *You don’t HAVE to do the Apps and Programs uninstall when you run DDU in Safe Mode, but I do it anyway just to “be safe”*
Run Custom Clean and Registry in CCleaner until there is no progress in cleaning. You don’t have to do this either, but I like removing any remnants of the old driver.
Plug in the eGPU. Open “Thunderbolt Control Center” and approve your device.
Once approved, it’ll be recognized for use. Install drivers with the Driver Slimmer to remove any unnecessary pieces in the driver package. Check everything in “Core Functionality” and forget about the rest unless you really need the other parts. See above picture for details.
Get out of airplane mode and install "Nvidia Control Panel" in the Microsoft Store (if using DCH drivers).
I know, I go through a lot of steps and some can be redundant. This is what I do to perfectly install drivers and extract maximum performance from my machines.
I did 2 comparisons, one at 1080P and another at 4K. Both laptops were using my “tweaked” settings to get the best possible performance out of them.
Let’s see how they did.
WOW.
On-die Thunderbolt integration really improved performance by a decent margin. When you look at the Synthetic benchmarks, it favorably shows that the Coffee Lake setup is superior but that's mostly due to more and faster cores. But when it comes to gaming, Ice Lake closely matches or beats the Coffee Lake CPU.
Remember, the Ice Lake CPU has 2 less cores AND is throttling down to 2.2GHz. This is a GAME CHANGER IMO and really makes eGPU as a system more feasible.
I REALLY have to emphasize that a 15W CPU that throttles and has 2 less cores is closely matching or BEATING a 45W CPU that doesn't throttle and has 2 extra cores when it comes to eGPU performance. That’s INSANE.
After getting these results, it makes me wonder just how much more Ice Lake will beat Coffee Lake if I could get it to run stable at 3.5GHz on all cores… hmm…
Overall, I'm pretty blown away by the performance improvement. I honestly didn't think that tighter integration would outweigh a slower CPU with a core disadvantage but my testing shows that it does. Kudos to Intel.
Conclusion
I’ve been a fan of Thunderbolt and eGPU since 2017 when I had an MSI GS43 and Sonnet eGFX 550. Recently, I stepped away from eGPU in favor of having a more powerful laptop, sacrificing portability and modularity. After obtaining these results from my tests, I’m VERY TEMPTED to purchase a Blade Stealth for myself. It was AMAZING being able to plug into my 1080P ultrawide monitor AND my 4K TV to play games. My GS65 with a 2080 Max-Q is SLOWER than the Blade Stealth with eGPU at 4K.
Even though I REALLY WANT to make a new setup for myself, I can only imagine how much better a possible Thunderbolt 4 will be in the future. Now that USB4 is unified with Thunderbolt 3, I’m hoping Thunderbolt 4 won’t be too far into the future.
If you're dead-set on a eGPU setup, I highly recommend going for an Ice Lake CPU over the previous generations, even though the CPU throttles. There are guides out there (like this one) that will instruct you on reducing/removing CPU throttling. Just keep in mind that there is a risk of bricking your system.
If you already have a 8th or 9th Gen CPU with a decent GPU (GTX 1660Ti or RTX 2060 and up), you may want to hold off on eGPU until your dGPU can't meet your needs. By then, you may want a new laptop anyway and HOPEFULLY there will be a new revision of Thunderbolt and H-class CPUs with Thunderbolt Integration.
One thing to note is that I WILL update this blog with eGPU results from Comet Lake after I complete my review of the MSI Prestige 14. Target is Mid-December, just before the holidays.
I hope this helps, have fun!
-The Everyday Enthusiast
Disclaimer – The Blade Stealth way provided by HIDevolution at my request. I’m not being compensated in any way by them. All thoughts of the machine are my own. Also, I purchased and own the GS65 and the Core X Chroma. The 1080Ti is borrowed from a friend.