08-03-2018 06:29 AM
Hello, I have watched some reviews and came up with the following questions. Could you please let me know the following?
1. It is advertised that the UHD version has a battery life of about 10-12 hours. Some reviewers mentioned that in practice, the battery life is half even doing light work. So, what is the "real" battery life in practice?
2. One reviewer mentioned that the UHD version could be turned to display in resolutions of FHD through windows without lost of clarity. Is that really true? If I switch to FHD mode, how many additional hours of battery life will I get? Will the text and images still clear? I would like to have the option of 4K when needed and when I want to save battery power, switch to FHD mode on the fly.
3. If I buy the UHD version and connect it to a 4K monitor/TV, will the internal graphics chips be able to handle 4K in both the LCD and the external monitor? I need a laptop to be able to drive external TV at 4K @ 60Hz with Chroma 4:4:4.
4. A reviewer mentioned that although there are two Thunderbolt 3 ports, they are actually shared. In other words, one cannot use a port to drive an external 4K display at 60Hz and at the same time charge the laptop using another port. Please clarify.
5. Can I use 3rd party external charger to charge this laptop rather than just the adapter which came with the machine?
08-03-2018 07:05 AM - edited 08-03-2018 07:05 AM
I have the FHD 920, 4K 910. So, I can't answer all of your questions.
1. Real-world use for me is about 5-7 hours. I can push it beyond that doing word processing in Airplane Mode with a dim screen. I can suck it dry in 4 hours doing video processing while running a virus scan and surfing the web.
2. I can only speak for my 910. I have to actually look at the settings to tell if it's doing 2160 or 1080.
4. Yes, you can use one port to charge and the other to run an external display.
5. Yes, but it might depend on the charger. Needs to be a USB-C charger that'll do 45W@20V minimum. And not all of those work as they should. Seems manufacturers test them with a Macbook and nothing else. Read the reviews before buying anything. I have two Lenovo chargers (obviously), an HP and a super-slim off-brand. The off-brand will charge the 920, but not the 910 when it's running.
08-03-2018 07:15 AM
Thanks for sharing your experience.
1. Are you talking about FHD 920 or 4K 910?
2. Do you see improvement in battery life when switched to 1080? If so, by how much?
08-03-2018 09:07 AM
1. The 920. Though the 910 performed about the same when it was new. It's about 2 years old now.
2. I notice no difference. That said, I haven't gone to the trouble to do any scientific testing. To do it properly, I'd need the same video running on the same settings (only changing resolution) in Airplane Mode until the battery died. While I DO have a good 4k test loop available and might do that sometime, I haven't so far. THIS, however, is on my 910.
08-03-2018 09:20 AM
You might want to drop back to the FHD, then. PCMag did the same sort of testing I was talking about and got 22 hours out of the battery. Nothing they tested did better. Food for thought.
08-04-2018 08:57 AM - edited 08-04-2018 09:02 AM
How does setting a 4k screen to 1080p save battery life? The screen is still 4k and still has all the pixels a 4k screen has. All 4k pixels need to be illuminated, managed and utilized.
I question is genuine . I have a 1080p screen. If I change the resolution to 640x480, how does my battery life improve?
Nevermind, I found the answer.
The GPU has fewer pixels to generate and therefor uses less power. There are still 4k pixels, but it mirrors more and has fewer to draw. That saves power. This is interesting to me, but good to know.