I have recently discovered that my laptop (running Windows 10 now) is suffering from a form of millisecond-stuttering or lag spikes (whatever floats your boat to call it)
I have done quite some research on it already, so you don't have to do it.
So, the laptop is a Lenovo Z50-70 (compatible with Windows 10)
I have performed a clean install of Windows 10 on it. Everything went smooth and still is running smooth, except for the issue I'm currently describing.
However, this issue did not occur after the clean installation. It occured before that already. It occured after upgrading to Windows 10 in a whole. (didn't occur back on Windows 8.1) I hoped it would be gone after my planned clean install, but it didn't.
To describe the issue in more detail:
The only way I could perceive it was through anything that is sound-related. Watching a video for example:
When someone in the video says "tenforums dot com"; when a lag spike occurs, it may sound like "terrrrnforums dot com" or "tenforrrrums dorrrt com", depending on when it happens.
Such a lag-spike / stutter is indeed very Micro, as it happens for a real fraction of a second.
All of this may not sound as a major issue to you, but it is quite an annoyance, especially when watching/editing videos and music.
I have observed the Performance tab in the task manager aswell. Whenever such a lag-spike occurs, there is no sign of increase in CPU usage or RAM usage.
Now, the following might sound like a wild thought, but I think the issue lies at the BIOS. (if that is even possible)
Before upgrading to Windows 10, I had done 2 updates of my BIOS version (as recommended by Lenovo on their site)
On Windows 8, the BIOS version was 19. I updated once to 31, without any issues, but before having the chance to upgrade to Windows 10 there was yet another BIOS update available, specifically made for Windows 10 compatibility: Version "91".
So I have updated to that version and after that I immediately did the upgrade process.
I kept on a "non-clean" windows 10 OS for a week or so before performing the clean install. During the that week I already suffered from the lag-spikes. (and now after the clean install I still do)
The reason I think it is BIOS-related is because that is the only similarity between the stages before and after the clean installation.
I highly doubt the problem is driver-related, because I still ran on the Windows 8 versions of all hardware drivers when simply upgrading to Windows 10. After the clean installation, I installed Windows 10 versions (or simply updated versions) of all the drivers. (given by Lenovo) But the BIOS version remained the same all the time.
(I cannot say if the lag-spike thingy already occured in Windows 8, immediately after updating to BIOS version "91", because as I said I immediately performed the upgrade process to Windows 10 after updating the BIOS)
I might be completely wrong (or paranoid ) here, but for me this seems the most logical explanation. I think my BIOS version is unstable and is causing those freeze-spikes.
Now, I know fuzzling with the BIOS can be very dangerous, but I am yet to try simply resetting the current BIOS settings to default (going into the bios tab and exiting with the option "load default settings")
Or, I have to downgrade the BIOS (which is probably not even possible) or re-flash version 91.
(I have met someone on the Lenovo Community, also having clean installed Windows 10 on the same laptop that I have and also running BIOS version 91. He's completely free from any problems)
Hopefully I gave you a better understanding regarding the issue and more hopefully someone might manage to help me out of here!