Bad disk performance on Win 8.1

run msconfig and disable services and programs from starting automatically which aren't really needed. Also make sure you have a good AV utility installed. For example, the symantec (norton) crap tends to really slow things down while Panda antivirus is very low on resources, but at least as good. I've been using the free version for years and haven't had any issue (the free version can only be used in a private environment).

As far as I know, Lenovo also includes a built-in backup which runs by default, it could be one of the reasons for your slow-downs.

@Gerald Connolly  - please let us know about backup as rindi suggested. Lenovo does have backup software but (a) it does not run at every startup and (b) it will ask first (prompt).

At startup from boot/sleep/hibernate the disk shows 100% active for the whole time, and at other times it doesn't take much to make it do the same.
As far as I aware Backup doesn't run at startup.
I use McAfee AV on this machine.

It didn't used to be this bad it seems to be getting slowly worse

Set up performance monitor to run for an hour or two. What is coming to the top? Please check for viruses as this now looms more likely.

As I mentioned run msconfig. Also uninstall software you don't need.

Besides that, there can be windows 8 crapps installed that "phone home", or need to update info from the web, and they may be doing that during bootup, or you are using an m$ account which connects to OneDrive and syncs your data with the cloud.

Yes I am using a hotmail account so the sync to one drive may be an issue. I also use Dropbox so they may be competing.

The process that seems most prevalent in the list is netsvc

Bizarrely it starts up more quickly from a cold start

I do not use One Drive but I do use Dropbox and I do sync with my iPhone.

Most services use memory and once stabilized, do not hog disk in my experience. I do understand what rindi is saying, but I have observed for years (XP, Vista, Seven and now Eight) that without stopping any services, the machine in question (different machines) will stabilize to less than 5% CPU and very low or zero disk activity.  

About netsvc:   Read this Microsoft Thread. It is several pages. Deep into the article the solution was cleaning out viruses.

http://answers.microsoft.com/en-us/windows/forum/windows_xp-performance/svchost-svchostexe-k-netsvcs-uses-90-cpu-usage/41ba79ae-5e92-44d2-91ba-0de886061b4f?page=2

netsvc is a service used by many different applications, so that alone doesn't really tell you anything.

I use windows 8.1 with onedrive and onedrive for business and I can assure you that is not a problem. Same goes for the Windows 8 Modern Apps.  Is your drive 5400rpm or 7200rpm is it a 'GREEN' drive? You might want to use the Windows Performance Toolkit and analyse your boot

you can also run a diag on the drive with the UBCD :
Hardware diagnostic CD    UBCD

go to the download page, scroll down to the mirror section, and  click on a mirror to start the download
Download the UBCD and make the cd   <<==on a WORKING PC, and boot the problem PC from it
Here 2 links, one to the general site, and a direct link to the download

since the downloaded file is an ISO file, eg ubcd527.iso - so you need to use an ISO burning tool
if you don't have that software, install cdburnerXP : http://cdburnerxp.se/

If you want also the Ram tested - run memtest86+ at least 1 full pass,  - you should have NO errors!
 
For disk Diagnostics run the disk diag for your disk brand (eg seagate diag for seagate drive)  from the HDD section -  long or advanced diag !  (runs at least for30 minutes)

http://www.ultimatebootcd.com/                        ultimate boot cd
http://www.ultimatebootcd.com/download.html             download page

**  you can make a bootable cd - or bootable usb stick

I find that having both DropBox and OneDrive running at start up really slugs machine performance. Then the AV kicks in and tries to update the AV definitions. Do you have iTunes or Spotify installed as well as these also all try to run at startup.

I believe on Windows 8.1 you can modify services from the taskmanager start-up tab as well as via MSCONFIG. Try turning off drop box and OneDrive and see what happens.

Also in my experience McAfee can be a resource hog...

I have a fast connection, FTTC so 60Mb down about 17Mb up but a lot of data in my One Drive. I saved the DVD ISo for Windows 10 there an it crippled everything for an hour or so while it synced...

The problem occurs both when i do and when i don't have an internet connection.

If it was some kind of interaction between Clouds, then why doesnt it happen when i do a cold boot, this only seems to happen when restarting after sleep

Dave, an SSD is on my list of things to try as the machine is not short of Horsepower and there is not much data being transferred to/from disk, it just looks like it is running out of IOPS

did you run a diag on the drive yet? post results plse !

Yes I ran HD Tune, which didn't show any problems and chkdsk which also didn't show any errors

What did Performance Monitor say after a couple of hours of running?

is this an upgrade, or fresh install of win 8?
an upgrade can take it's problems with it

It is the factory install 8.0 that came with the laptop, upgraded to 8.1

It is the factory install 8.0 that came with the laptop, upgraded to 8.1  <-- Windows 8.1 is a different operating system from Windows 8 (not a service pack), The upgrade may have gone wrong.

I solved my problem by installing a SSD (Samsung), just cloned the spinning rust and the machine nows runs brilliantly. Startup completes within seconds, everything is snappy. The SSD gives only about 2x MB/s, but as i thought the problem was obviously with IOPS.