01-08-2019 10:16 PM - edited 01-10-2019 02:20 AM
I seem to have hit a bug that I'm surprised hasn't been reported before. If you have a w530 with 32 GB RAM (technically anythng more than 16), and set your display settings to "integrated only; disable OS detection of optimus", the system comes down to a crawl. This is independent of the OS. I confirmed it with both linux and windows. You would not hit this if you set the display to optimus or discrete only. Can others reproduce this ? The rest of my bios settings are pretty standard. virtualization and vt-d are both enabled.
Note: You will not hit this issue if you only populate 2 slots of RAM with 8 GB each (i.e. total 16 GB), but you will hit it with 3 slots (i.e., 24 GB).
01-10-2019 12:52 AM
Did you connect an external monitor?
01-10-2019 02:07 AM
No, this is with the laptop's internal panel. Ironically, this is a problem with the "integrated only" option, which typically is stable. In the past, people have reported issues with optimus and/or discrete options in the bios.
This issue is specifically with "integrated only" and "OS detection of optimus disabled" coupled with large RAM.
01-10-2019 02:47 AM - edited 01-10-2019 02:51 AM
Found a very similar issue from a post back in 2012. It's the exact same issue: https://forums.lenovo.com/t5/ThinkPad-P-and-W-Series-Mobile/W520-Who-is-running-32GB-of-ram/td-p/851... reported for w520. Based on that, it looks like a bios regression.
01-17-2019 08:28 PM - edited 01-17-2019 09:15 PM
I'm having this exact same issue.. It's really a bummer. I get half of the battery life without using integrated mode. You can't really downgrade without opening up to some of the major intel & sidechannel recent CVEs :/
I'm actually on 2.72, and there is a 2.73 released. I'll try to update and we'll see if this fixes the problem. If not, I might just have to consider downgrading to 2.69+ and see what the latest BIOS I can run is, and just hope that software patches provide enough security, I guess??
01-17-2019 10:49 PM
I'm fairly certain that this is not recent. That post about W520 is from 2012. I don't think you'll have much luck with rolling back a few versions of the BIOS.
01-17-2019 11:55 PM - edited 01-18-2019 12:04 AM
Welp. I just tried both 2.69 (the earliest I can roll back to, at least according to support docs) and the latest 2.73, neither of which made a single difference. Also tried fiddling with several BIOS settings; no luck. When I first got the machine about a year ago, I did not have this issue... but I updated the BIOS not too long ago. Not sure what version it was on... too bad there's no warning or disclaimer...
I guess I can sell the RAM (even though that's explicitly why I bought this machine). I'll be needing to carry this around. Battery life is far too poor on Optimus, even with a huge extended battery :/
01-18-2019 12:08 PM - edited 01-18-2019 12:10 PM
You could go back to a really old version of the BIOS (like the first version this shipped with). I haven't had the time to do more experiments, but it is possible. You need to disable bios rollback protection in the bios settings, and use winflash64.exe /sd /file <path_to_.fl_file> to flash the bios.
The point of this exercise is to bissect the regression (if it is a regression), not to use an older version permanently.