Quote from: RayKeram on April 20, 2018, 20:12:33
The review says both "The display flickers at 100 % brightness and lower" and "Flickering detected at a brightness setting of 99 % and below". Which one is correct? I haven't seen any other reviews where the laptop screen was flickering at full brightness and that seems worrying.

Might this be a mistake? The panel is said to be identical to the one in the predecessor T570. Back in T570 review it was stated:
"The display backlight flickers at 925.9 Hz (Likely utilizing PWM) Flickering detected at a brightness setting of 90 % and below. There should be no flickering or PWM above this brightness setting."

I would be very grateful if the author of the review could please respond which of the (now three possible) statements about PWM flickering is true.

Why battery life of P52s is so much better? I know it's fullhd only... but it is also 100 gram heavier...  and it needs 30% more time to charge....

Are you sure you had the same set of batteries?

Agressive PWM and one cooling fan for both cpu and gpu. Disappointed.

Quote from: RayKeram on April 20, 2018, 20:12:33
The review says both "The display flickers at 100 % brightness and lower" and "Flickering detected at a brightness setting of 99 % and below". Which one is correct? I haven't seen any other reviews where the laptop screen was flickering at full brightness and that seems worrying.

Bump to this. Would also like to know.

The review says both "The display flickers at 100 % brightness and lower" and "Flickering detected at a brightness setting of 99 % and below". Which one is correct? I haven't seen any other reviews where the laptop screen was flickering at full brightness and that seems worrying.

I wonder if this machine would be better off all around with an i5-8350u at least for multi-core processing.   Lower power use, lower heat.  It wouldn't be hitting up against power and thermal limits as much,  likely wouldn't need to run the fan as often to fight heat... its overall performance might be better.

Dual batteries provide a unique capability not possible in single battery solutions...  continuous runtime in the field with a simple battery swap while the computer is still running.   Some wonder why its there at all while others wonder why more computers don't support it.   I've wanted dual batteries in the P series for a long time...  at least the new 8th gen chips are finally brining quad core to the T series dual battery laptops.

Why does Lenovo insist on 2 batteries?  If they can just do what they did with the Carbon series, which is what most of their competitors are doing, use 1 big battery.  That gives more room to the inside of the computer near the back, so Lenovo can use better cooling systems and use more powerful chips.

Hi, thanks for your wonderful review.
I was planning to buy this model, but after reading your review I started to worry about the coil whine. Is this so serious that could affect normal usage? Frankly I don't know exactly what coil whine noise is, is it some sort of high-pitch noise?

The 2242 M.2 slot for WWAN / second SSD is located below the M.2 slot for the WiFi card and to the left of the CPU. You can see the WWAN antennas in the picture, which are of course not connected to anything in the picture, as this unit doesn't have a WWAN card.

@Benjamin Herzig

I agree on the screens...  I'm actually find with FHD on this model if they would make a 300nit screen available... or even something that was consistently closer to 300 than 250... but all they offer at FHD is 250nits that often comes in around 230nits on average in reality. 

Where is this M.2-slot for wan / second ssd?  Looking at the open picture there doesn't appear to be one unless its on the other side of the motherboard?

@DigitalAlchemist,

you are forgetting the M.2-slot for the WWAN / a second SSD, which at least takes two additional PCIe lanes (if not three).

I think I have read somewhere that all the current ThinkPad T series has two-lane Thunderbolt 3. The X1 ThinkPads all have four lane TB3, as does the P series (at least P51 and P71, I think the P52s has the same limitations as the T580).

Regarding the screen, I would be careful to take the 280 nits we measured for the T480 as "it will always deliver 280 nits". Lenovo has specced it at 250 nits for a reason and there are several different display-panels used. Plus, screens always vary in brightness. The T480 FHD screen may deliver 280 nits on one unit, it may only deliver 230 nits on another. Its likely the same situation for the T580 FHD screen, which are spec-wise unchanged from the mediocre screens used in the T570.

Great review as always... and one (along with the p52s and yoga 730) that i've been impatiently awaiting.   I have a t560 now and the t580/p52s are obvious upgrade options for me.   The screen brightness and battery life are both a big disappointment though.   A couple questions...

On the t480 the FHD screen option was spec'ed at 250nits but actually delivered around 280.   Have you seen a t580/p52s with FHD screen to see if it follows suit?   

Part of the battery life and high idle times coult be attributed to the screen.   Even the 3k screen in the t570 knocked hours off its battery life.  But it looks like your test was with the 72wh removable battery which should have given better results.   Perhaps its due to the higher watt limits used on the 8550u or that its cooling system just has to work to hard because it can't keep up.    They probably should have added a 2nd fan.

Also... is the thunderbolt 3 4 lane?   The 8550u has 12 lanes...  4 for the mx150, 1 for wifi, another 2 in this for the ssd.   So there would be 4 available for tb3... where many 8xxxu cpu machines with dedicated graphics can only do 2 lanes on the TB3.