The Lenovo Legion 7i gaming laptop uses a vapor chamber cooler, but is this enough to keep it cool and performing well?
I’ve tested thermals with the 8 core i7-10875H processor and Nvidia RTX 2070 Max-Q graphics to find out just how hot it gets and see where the limits lie. 
Air comes in through the vents underneath towards the back, and is exhausted out of the back corners
and on the left and right sides towards the back.
There are a couple of fans inside and a vapor chamber cooler, though it seems that the cheaper 7i with 2060 graphics and below just has standard heatpipes. 
The Lenovo Vantage software lets you select between different performance modes, which from lowest to highest are quiet, balanced and performance modes.
You can also swap between these by pressing function and Q, and the light on the power button will change to reflect this. Unfortunately it’s not possible to change fan speed manually, and undervolting is disabled, which seems to be the case with many 10th gen laptops.
Although the RTX 2070 is Max-Q, it’s using Nvidia’s new Dynamic Boost, which means the power limit can boost higher depending on if there is power available. I saw a 105 watt average in a GPU only stress test, but it will be less with the CPU active.
Thermals were tested with a 21 degree Celsius ambient room temperature. Idle results down the bottom were ok. 
Worst case stress tests were done with the Aida64 CPU stress test with CPU only checked and the Heaven benchmark at max settings at the same time, while gaming was tested with Watch Dogs 2 as I find it to use a good combination of processor and graphics. Quiet mode was the coolest on the CPU, though while gaming the GPU temperature was higher than others, but no GPU thermal throttling was observed.
The CPU on the other hand was thermal throttling any time it was listed at 94 degrees celsius, and this was happening in the highest performance mode with highest fan speed, and only removed while gaming with the cooling pad.
These are the average clock speeds while running the same tests. 
In general, the GPU speeds were better in performance mode, and we see the CPU speeds increase as we step up through the modes. Even with the cooling pad though, we’re seeing 3.6GHz over all 8 cores in this workload, so not amazing, though I’d expect better results with the 6 core CPU configuration as there are fewer cores to power.
Quiet mode limits the processor to 25 watts. PL1 raises up to 45 watts in balanced mode, but as thermal limits were hit in this stress test we’re not reaching that. 
PL1 then raises up to 55 watts in performance mode, but again for the same reason it’s not being reached. The GPU results were a bit all over the place, I think this might be due to dynamic boost as the stress test was running it at 80 watts then 90 and above in performance mode. With the CPU being smashed though, we’re not seeing the GPU run at its 105 watt limit. 
In a CPU only stress test with the GPU now idle, quiet mode still caps the CPU to 25 watts, however balanced mode now boosts this to 60 watts.
Although performance mode boosts this up to 85 watts, in this long term stress test thermal limits were being hit
this would be less of an issue for shorter burst style workloads though, so it’s still useful to have those higher power limits in place.
Even in this CPU only workload, the all core 4.3GHz turbo boost speed of the i7 isn’t being hit due to thermal limitations. 
I’ve used Cinebench to show you how these different modes perform. 
Single core performance doesn’t change too much, and then performance mode isn’t much higher than balanced for multicore due to thermal limits.
When we look at how this stacks up against others
well it’s the lowest multicore result I have for an 8 core laptop so far, so those thermal limits really seem to be holding it back.
There’s not that much difference in a game when comparing the different performance modes, though the cooling pad still did help out a little, presumably as temperatures are still a limitation in this test.
At the same time, when compared to other laptops the performance appears to stack up ok.
If you want to see more gaming benchmarks from the Lenovo 7i, check out article where I’ve tested 20 games at all setting levels.
As for the external temperatures where you’ll actually be putting your hands, at idle in quiet mode it was in the low 30s, pretty standard. 
With the stress tests running it gets to the mid 40s in the center, wasd was still cool though.
Stepping up to balanced mode and the middle is now just a little warmer. 
In performance mode it’s similar but just a little cooler, and this is due to the fans getting louder.
At idle the fans were just audible. With the stress tests running in quiet mode, it’s not too loud when compared to other gaming laptops. Balanced mode was a little louder, then the highest performance mode increased the fans more, putting total system noise close to most others I test in their maximum performance mode.
Although for the most part the performance in games is pretty good, when both the CPU and GPU are being hit the processor seems subject to more thermal throttling when compared to many other laptops I’ve recently tested, but again this would probably differ with the 6 core config. I did think it would be a bit better due to all the hype of the vapor chamber cooler.
In CPU only workloads where the processor is consistently being loaded, the thermal throttling takes its toll as this is the lowest multicore result from an 8 core laptop I’ve tested. It’s unfortunate that further tweaking cannot be made in the way of undervolting, as that could give it the extra edge needed, but that was locked down with the latest version of BIOS.
I think the power higher limits are good, but the thermal throttle cap is still being hit and limiting performance in multicore workloads, which is why using a cooling pad helps in many cases. This should at least mean that shorter burst style workloads still see good processor performance, as they can run at higher power levels up until things heat up. Let me know what you thought about the thermals from the Lenovo Legion 7i gaming laptop down in the comments.
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