Lenovo IdeaPad L340 Gaming - Why So Slow?

Today we’re going to have a look into the disappointing performance of Lenovo’s Ideapad L340 Gaming laptop, how it compares to a similarly equipped Dell G15, and what you can do to dramatically improve the machine’s performance.

The IdeaPad L340 Gaming is a budget gaming laptop, introduced in 2019. Its design is shared with other basic, lower-end IdeaPad machines, but with a beefed up cooling solution to handle the 50-watt GeForce graphics chip.

I wouldn’t recommend buying a new L340 Gaming at this point in time. There are much better options available for a similar price, including Lenovo’s own IdeaPad Gaming 3.

However if you’ve already got one and you’re finding the performance to be pretty poor, this guide is for you.

The L340 I have here is equipped with a Core i5 9300H quad-core processor, Geforce GTX 1650 graphics, and 8GB of RAM in single-channel mode.

Unfortunately, that single-channel RAM is mandatory - there is only one RAM slot on this machine & no RAM soldered to the board, so there’s easy performance improvement to be had there.

For performance comparison purposes, we’ll be using a basic Dell G15 5510, equipped near-identically with a Core i5 10200H quad-core CPU, 8GB of RAM in single-channel (this is to ensure an accurate demonstration of the L340’s performance issues), and a GTX 1650.

Both of these machines are being tested at completely stock settings. Neither CPU is undervolted – not yet – and the GTX 1650s have not been overclocked. Nvidia Dynamic Boost is disabled on the Dell G15 so both GPUs are capped at 50 watts TGP.

For each machine, I’ve chosen to benchmark Cyberpunk 2077 at Low graphics settings and Watch Dogs Legion on Medium.

Frame rate results are taken using MSI Afterburner’s benchmark feature.

In Cyberpunk, the L340 averages just 28 frames per second, while the G15 is managing 35.6. 1% and 0.1% lows on both machines are pretty bad. Subjectively though, the game did feel significantly smoother on the Dell machine.

Moving on to Watch Dogs: Legion, we’re looking at a similar large gap between the two in average framerates, although interestingly the 0.1% lows on the G15 are actually worse than the L340’s.

So you might be wondering, if these machines are so similarly configured, why is the Dell G15 so much faster?

Let’s dig in.

Unfortunately, Lenovo have set up the power & thermal management on the L340’s CPU very poorly, initially pumping in far more power than the cooler is capable of dealing with, and then throttling excessively hard once the cores get hot.

To show this effect in action, we’ll quickly run Cinebench while focusing on the CPU power & temperature readouts in HWMonitor.

Watch what happens here.

First, the CPU power hits 55 watts, and Core 0 on the hits 94 degrees:

Then, in a panic, the entire package drops to less than 20 watts in some of the most aggressive thermal throttling I’ve ever seen:

Moments later, the power rockets back up to 50+ watts and the process repeats itself over and over.

This is the last thing you’d want to see on a gaming laptop, where steady power delivery is mandatory for smooth gameplay.

On that note, let’s see how it looks while running a game:

Well. This is a complete disaster. The processor is stuck at 2.4GHz, CPU usage is completely maxed out, and even the weak GTX 1650 isn’t at 100% utilization, being bottlenecked pretty hard by the throttled CPU.

Thankfully, there is a workaround to eliminate this.

Undervolting the CPU is not disabled on the L340 Gaming, and as it turns out we can completely override Lenovo’s factory settings for power control using ThrottleStop.

ThrottleStop is a small utility that can - on certain laptops - take control of power delivery to the CPU.

If you’re not familiar with installing & using this software, an excellent guide can be found here: www.ultrabookreview.com/31385-the-throttlestop-guide/

Here’s the settings we need to change for the L340.

Firstly, jump into the power limit settings, labeled “TPL” from the main window.

Towards the right-hand side are two text entry boxes where you are able to specify power limit settings.

In my testing, the L340 can easily cool up to around 30 watts, so I’ve set both the short-term (PL2) and long-term (PL1) power to 30.

Make sure to click the “lock” check box just to the right.

Now that we’ve dropped the power limits, we can undervolt the CPU to maximise the clock speed it will run at under the new 30-watt limit.

Back in ThrottleStop’s main window, click the button labeled “FIVR”:

In the FIVR control window, focus on the area outlined in red below:

Under “FIVR Control”, make sure that “CPU Core” is selected.

Now underneath CPU Core Voltage, you can pick an undervolt about, presented as “Offset Voltage”.

Typically, these chips will handle around a -100mV undervolt.

You can try -100mV first and reduce it (i.e., drop to a lower offset like -75mV) if the system proves unstable.

My L340 was happy to run at -125mV, as you can it set to here.

To save your settings, select “OK - Save voltages immediately” in the bottom right-hand corner, then click Apply.

Now, we are simultaneously forcing the CPU power delivery to cap itself at 30 watts to avoid triggering throttling, and undervolting the CPU to cause it to clock up as high as possible within a lower power limit.

So, let’s see how well this works.

Running Cinebench R23 again, the CPU is running at a constant 30 watts, and going nowhere near the 94 degree thermal throttling limit - in fact, temperatures are impressively low. This is a good start.

Now jumping back into Cyberpunk, you can see that we’re getting a solid 30 watts on the CPU which is now running at around 4GHz, the GTX 1650 is being almost fully utilized, and we’re getting framerates somewhere around 30 percent higher.

Big difference.

Finally, here’s the benchmarks I showed earlier, but with the L340 with the locked power limits added in at the top.

And would you believe it, the L340 is now getting the highest framerates in both games.

How’s that for a result?