Hi!

Today I noticed high temp (~65°C) when coming out of screensaver, i.e., moving the mouse after the desktop go into screen lock mode.

Idle temp is usually ~ 45°C.

Desktop is an i3 running oS 13.2 64-bit KDE4.14.9, nvidia blob for GTX 650 with two 24" same model monitors attached, one through DVI and the other with a HDMI-DVI cable (monitors only have DVI ports).

In system-settings, Screensaver is set to start after 1 minute (Screen & Monitor > Session Locker) and power savings is set to 2 min for screen darkening (not an exact translation) and 3 min to switch the screen off.

Running top in batch mode I get idle CPU usage until screensaver kicks in:
Code:
top - 17:38:34 up  2:38,  4 users,  load average: 0,16, 0,29, 0,32
Tasks: 236 total,   2 running, 233 sleeping,   0 stopped,   1 zombie
%Cpu(s):  4,1 us,  1,4 sy,  0,0 ni, 94,3 id,  0,2 wa,  0,0 hi,  0,0 si,  0,0 st
KiB Mem:  16402508 total,  4289380 used, 12113128 free,   204284 buffers
KiB Swap:  2097148 total,        0 used,  2097148 free.  2670512 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 5819 blimmer   20   0  464460  77780  56240 R 5,648 0,474   0:00.17 kscreenlocker_g
 2411 blimmer   20   0 4462808 477756 178104 S 4,319 2,913   6:51.56 plasma-desktop
 1063 root      20   0  275404 185524 147124 S 3,654 1,131   5:45.55 Xorg
 2394 blimmer   20   0  574024  54432  32124 S 2,990 0,332   0:02.05 ksmserver
  993 polkitd   20   0  516844  21736   9172 S 0,997 0,133   0:00.93 polkitd
 2402 blimmer   20   0 3159512 154464  89624 S 0,997 0,942  24:34.92 kwin
 2409 blimmer   20   0  782304  84756  53088 S 0,664 0,517   0:40.06 krunner
...
Between screensaver and screen off (two minutes duration, notice the time stamps) kwin ramps up to 100% of one core and stay there:

Code:
top - 17:38:37 up  2:38,  4 users,  load average: 0,16, 0,29, 0,32
Tasks: 238 total,   2 running, 235 sleeping,   0 stopped,   1 zombie
%Cpu(s): 19,2 us, 11,5 sy,  0,0 ni, 69,1 id,  0,1 wa,  0,0 hi,  0,0 si,  0,0 st
KiB Mem:  16402508 total,  4374488 used, 12028020 free,   204292 buffers
KiB Swap:  2097148 total,        0 used,  2097148 free.  2706668 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 2402 blimmer   20   0 3213532 154484  89624 R 54,00 0,942  24:36.54 kwin
 1063 root      20   0  311404 221424 183024 S 26,33 1,350   5:46.34 Xorg
 5819 blimmer   20   0 2919488 164404 106352 S 21,33 1,002   0:00.81 kscreenlocker_g
 2411 blimmer   20   0 4462808 477756 178104 S 5,333 2,913   6:51.72 plasma-desktop
 5822 blimmer   20   0  290164  37700  32604 S 4,000 0,230   0:00.12 kblankscrn.kss
 5823 blimmer   20   0  290156  37432  32340 S 4,000 0,228   0:00.12 kblankscrn.kss
 2394 blimmer   20   0  574024  54432  32124 S 2,667 0,332   0:02.13 ksmserver
 2409 blimmer   20   0  782304  84756  53088 S 1,000 0,517   0:40.09 krunner
...

top - 17:38:40 up  2:38,  4 users,  load average: 0,31, 0,32, 0,33
Tasks: 238 total,   2 running, 235 sleeping,   0 stopped,   1 zombie
%Cpu(s): 15,3 us, 15,0 sy,  0,0 ni, 69,3 id,  0,4 wa,  0,0 hi,  0,0 si,  0,0 st
KiB Mem:  16402508 total,  4375676 used, 12026832 free,   204308 buffers
KiB Swap:  2097148 total,        0 used,  2097148 free.  2707260 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 2402 blimmer   20   0 3213532 154484  89624 R 100,0 0,942  24:39.55 kwin
 2411 blimmer   20   0 4462808 477756 178104 S 14,95 2,913   6:52.17 plasma-desktop
 1063 root      20   0  311404 221424 183024 S 3,654 1,350   5:46.45 Xorg
 2466 blimmer   20   0  378412  40508  34420 S 0,997 0,247   1:34.68 qsynergy
...

top - 17:38:43 up  2:38,  4 users,  load average: 0,36, 0,33, 0,34
Tasks: 238 total,   2 running, 235 sleeping,   0 stopped,   1 zombie
%Cpu(s): 12,2 us, 14,7 sy,  0,0 ni, 73,0 id,  0,1 wa,  0,0 hi,  0,0 si,  0,0 st
KiB Mem:  16402508 total,  4375676 used, 12026832 free,   204316 buffers
KiB Swap:  2097148 total,        0 used,  2097148 free.  2707360 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 2402 blimmer   20   0 3213532 154484  89624 R 99,67 0,942  24:42.55 kwin
 2411 blimmer   20   0 4462808 477756 178104 S 2,990 2,913   6:52.26 plasma-desktop
 1063 root      20   0  311404 221424 183024 S 1,329 1,350   5:46.49 Xorg
 2466 blimmer   20   0  378412  40508  34420 S 0,997 0,247   1:34.71 qsynergy
 2409 blimmer   20   0  782304  84756  53088 S 0,664 0,517   0:40.12 krunner
...

top - 17:40:31 up  2:40,  4 users,  load average: 0,88, 0,52, 0,40
Tasks: 237 total,   2 running, 234 sleeping,   0 stopped,   1 zombie
%Cpu(s): 12,7 us, 14,8 sy,  0,0 ni, 72,3 id,  0,2 wa,  0,0 hi,  0,0 si,  0,0 st
KiB Mem:  16402508 total,  4376048 used, 12026460 free,   204628 buffers
KiB Swap:  2097148 total,        0 used,  2097148 free.  2711272 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 2402 blimmer   20   0 3213532 154484  89624 R 100,7 0,942  26:30.85 kwin
 2411 blimmer   20   0 4462808 477756 178104 S 4,333 2,913   6:56.67 plasma-desktop
 1063 root      20   0  311404 221424 183024 S 3,333 1,350   5:49.46 Xorg
 2409 blimmer   20   0  782304  84756  53088 S 0,667 0,517   0:40.83 krunner
...


top - 17:40:34 up  2:40,  4 users,  load average: 0,89, 0,52, 0,41
Tasks: 236 total,   1 running, 234 sleeping,   0 stopped,   1 zombie
%Cpu(s): 12,5 us, 12,1 sy,  0,0 ni, 72,1 id,  3,2 wa,  0,0 hi,  0,0 si,  0,0 st
KiB Mem:  16402508 total,  4372472 used, 12030036 free,   204640 buffers
KiB Swap:  2097148 total,        0 used,  2097148 free.  2711348 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 2402 blimmer   20   0 3232168 154484  89624 S 81,73 0,942  26:33.31 kwin
 1063 root      20   0  311404 221424 183024 S 4,651 1,350   5:49.60 Xorg
 2388 root      20   0  355768   7836   6048 S 4,319 0,048   0:05.73 udisksd
 2411 blimmer   20   0 4462808 477756 178104 S 3,654 2,913   6:56.78 plasma-desktop
 2466 blimmer   20   0  378412  40508  34420 S 1,329 0,247   1:35.79 qsynergy
 2409 blimmer   20   0  782304  84756  53088 S 0,664 0,517   0:40.85 krunner

top - 17:40:37 up  2:40,  4 users,  load average: 0,89, 0,52, 0,41
Tasks: 236 total,   2 running, 233 sleeping,   0 stopped,   1 zombie
%Cpu(s):  3,8 us,  0,8 sy,  0,0 ni, 90,3 id,  5,1 wa,  0,0 hi,  0,0 si,  0,0 st
KiB Mem:  16402508 total,  4401072 used, 12001436 free,   204648 buffers
KiB Swap:  2097148 total,        0 used,  2097148 free.  2711396 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 2411 blimmer   20   0 4462808 507736 178104 R 6,977 3,095   6:56.99 plasma-desktop
 2388 root      20   0  355768   7836   6048 S 3,987 0,048   0:05.85 udisksd
 1063 root      20   0  311404 221424 183024 S 3,654 1,350   5:49.71 Xorg
 2466 blimmer   20   0  378412  40508  34420 S 0,997 0,247   1:35.82 qsynergy
 2402 blimmer   20   0 3232168 154484  89624 S 0,664 0,942  26:33.33 kwin
If I disable screensaver - monitor gets switched off after a few minutes - there's no CPU usage / temperature increase.

The screensaver is nice but not important, so I'll leave it off.

I googled the issue but couldn't find anything similar reported, the closer was https://forums.opensuse.org/showthre...-loop-100-load

Any suggestions?

TIA