Sudden drop in disk drive read rate after switching to KDE and back to Gnome

I switched to KDE to try it out.

Everything was running incredibly slow.

I switched back to Gnome and everything was slow.

The first problem was that my video adapter was no longer being detected (using lvmpipe or some such). I fixed that.

Now my read speed has gone from an average 130 MB/s to 12 MB``

# hdparm -Tt /dev/sda

/dev/sda:
 Timing cached reads:   14706 MB in  2.00 seconds = 7357.75 MB/sec
 Timing buffered disk reads:  40 MB in  3.15 seconds =  12.69 MB/sec

The disk drive (1 TB) is no where near full and as above, the system degradation happened with the switch to KDE as well as when back to Gnome.

I'm wondering if a generic disk driver is now being used instead of one for Western Digital.

lshw -class disk
----- relevant disk follows ------
  *-disk
       description: ATA Disk
       product: ST1000DM003-1SB1
       physical id: 0.0.0
       bus info: scsi@0:0.0.0
       logical name: /dev/sda
       version: HPH5
       serial: ZN1DWYWA
       size: 931GiB (1TB)
       capabilities: partitioned partitioned:dos
       configuration: ansiversion=5 logicalsectorsize=512 sectorsize=4096 signature=a8b54638

Filesystem      Size  Used Avail Use% Mounted on
udev             32G     0   32G   0% /dev
tmpfs           6.3G  2.7M  6.3G   1% /run
/dev/sda5       916G   97G  773G  12% /
...etc

I have not figured out the particulars yet; however, I found, through running iotop, that an app I use (insync) was at 99% io and iostat showed an average of 140-160 tps at all times. So the IOPS was very high throttling all disk IOs.

I'm guessing that in switching to KDE this caused a problem with insync which is auto-started on boot up.

There is still the odd issue of my video driver getting swapped out when I loaded KDE, but all's well that ends well :)

post note: I also found that baloo file extractor (part of KDE) was churning up a huge amount of IO. Apparently, reverting back to gnome does not stop it from running on boot. Thus, the insync issue was making the baloo problem even worse. However, baloo by itself causes boot times to go from mere seconds to over a minute.