Occasional micro-stuttering / lag-spikes

Good day,
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!
Thank you!

Hi @Sonar637

I cannot see how you would be harmed by reflashing the new BIOS.

If you have Macrium Reflect (and you should). Take a system image of your C: drive, and then reflash the bios.

Try and see if you still have the same issues. I'll be happy to continue to help you if the micro-stuttering continues after you reflash the lastest BIOS.

Thank you for replying,
I have gone into my BIOS yesterday and saved & exited with the "load default settings" option.
When I rebooted the PC, everything seemed to be working fine. I did not have any form of micro-stuttering, but ofcourse I wouldn't let me give myself false hope.
Today I turned the laptop on again. I did have a few micro-stutters now, but for some reason it's becoming less and less occasional over time. (which is weird, a PC cannot 'heal' itself over time as for example a human body, does it? Although I have had numerous occassions that I find it to act this way...... )

Maybe it didn't "save" the fact that I resetted the BIOS settings to default? (Although I did save & exit)
I have never changed any BIOS settings before at all.

I wanted to try re-flashing my BIOS today, but it is unable to do so.
Lenovo has a list of drivers on their site, specifically designed for my laptop model. The BIOS they offer is packed inside a flash utility, which is simply a .exe to run. When re-downloading the version 91 exe and running it, it couldn't proceed as my BIOS is already at version 91.
So far, there is no other way to flash my BIOS but with Lenovo's own .exe utility. That is all they offer me.

However, if you had other "diagnostical" procedures in mind that we could try, I would be glad to do so. :)
(As I said, blaming the BIOS might be a wild guess)

Sonar637 said:

Thank you for replying,
Today I turned the laptop on again. I did have a few micro-stutters now, but for some reason it's becoming less and less occasional over time. (which is weird, a PC cannot 'heal' itself over time as for example a human body, does it? Although I have had numerous occassions that I find it to act this way...... )

Maybe it didn't "save" the fact that I resetted the BIOS settings to default? (Although I did save & exit)
I have never changed any BIOS settings before at all.

I wanted to try re-flashing my BIOS today, but it is unable to do so.
Lenovo has a list of drivers on their site, specifically designed for my laptop model. The BIOS they offer is packed inside a flash utility, which is simply a .exe to run. When re-downloading the version 91 exe and running it, it couldn't proceed as my BIOS is already at version 91.
So far, there is no other way to flash my BIOS but with Lenovo's own .exe utility. That is all they offer me.

However, if you had other "diagnostical" procedures in mind that we could try, I would be glad to do so. :)
(As I said, blaming the BIOS might be a wild guess)

Actually I never believed it was the BIOS but happy to exclude that as an issue if it made you feel better.

I suspect that your machine hasn't yet fully done its superfetch caching. So you're experiencing mini stutters while it does that (or search is doing its caching). Over time, I expect it will smooth out. Have you fully updated this machine?

I don't wan't to jump the gun here, but there are quite a few ways to mediate the issue.

It would be helpful if you would update your system specs so I know what kind of machine I'm working with.

If you don't know everything that's in your machine, you can use this tool:
Speccy - System Information - Free Download

Download and install the free version

Please don't forget to note what your AV is. That is another likely culprit.

I'm not sure what the superfetch caching actually is, but as I mentioned, the micro-stuttering occured after upgrading to Windows 10 and it remained after performing a clean installation.
You may be right about the caching and that it'll eventually be over (might explain the diminishing strength of the freezes?), but we'll just keep searching for now.

The laptop is a Lenovo Z50-70 (which is probably the same name of the motherboard)
Some of my specs from msinfo32:
(Windows 10 version 10.0.10240)
(64-bit device)
Intel Core i7-4510U CPU @ 2.00GHz, 2601 MHz, 4 CPUs
BIOS version 9BCN91WW from 21/07/2015 (Type is UEFI)
8 GB of RAM (PC3-12800 DDR3L SDRAM 1600 MHz)
Hybrid GPU: Integraded intel HD Graphics and an NVIDIA GeForce 840M 4GB (driver version 355.60; untouched, not overclocked or anything)
1 TB HDD

The antivirus is Avira (free version). I have used it for a few years now, never had any problems been caused by it. After the clean installation, I remember that the stuttering already occured before I installed Avira or my firewall (Comodo)

satchmo said:

It only happens when you play videos? Do you play the video within your browser or with a separate video player?

The DVD player for Windows 10 is known to stutter.

It happens everywhere. YouTube/Browser, VLC Media player, Windows Media Player, Windows 10 video player, Audacity, iTunes, you name it. It's 'global'. I only discovered it because of stuttering during sound-playback. Otherwise I would never be aware of its existence

Is your machine using the same drivers that it used on Windows 7, or did Windows 10 install generic drivers?

Also. What kind of hard drive do you have?

It would also be useful to know how the drive is partitioned.

Can you right click on the Start Menu, click Disk Management, and screenshot and post please?

Well, it came from Windows 8, not windows 10 (talking about my laptop here, not my desktop)
If you search "lenovo Z50-70 drivers" on google and get the first one (I think), you'll find a whole list of hardware drivers given by Lenovo itself. They have drivers specific for each OS version, including Windows 10. I took these one, they are more "recent" version than those from 8.1.

About the disk management, here's the screenie. (It's in Dutch, sorry for that)
When performing the clean install, I only formatted the main partition (the one which is now called Windows10_OS). I didn't touch the others
However I'm not sure if this is of much concern as the stuttering already occured before the clean install, after simply upgrading to Win10... Or is it?

Edit: About my hard drive itself. I found the tab containing info about it, but I'm not sure if you could use the information.
HDD Model ST1000LM014-SSHD-8GB
512 Bytes/sector
63 Sectors/track
6 partitions
Medium loaded: yes
Type of medium: Hard drive
Tracks/cylinder: 255

Apologies for not getting back to you before now @Sonar637.

How is it now?

Any changes?

Has it settled down?