I started with Ubuntu 11 a few weeks ago. It's on a DELL M4300 with a OCZ SSD. Default setup, except that I've installed the proprietary NVIDIA graphics and BROADCOM wireless drivers. Dual boot with Windows.

If I cold boot into Ubuntu, it is very fast, just like the Windows experience that I'm used to. But SOMETHING happens, and I haven't yet determined what, but the system gets incredibly slow and stays that way.

At first I thought it had to do with Adobe Flash because it seemed to be triggered by sites with Flash. But then I removed Flash and the problem remains.

I thought it was just an overheating problem, but I've now upgraded to 12.04 which supposedly fixes the overheating problems I've read about. Perhaps the heat situation was brought on by Flash in my early cases? So I installed Jupiter for CPU management, but the thermometer reports a familiar Windows-side temperature of 53 degrees Celsius. Switching Jupiter to lower performance doesn't help.

When I check the System Monitor application, sorting by CPU usage, there are no obvious problem processes. However, in the graphs tab, both CPU cores are pegged at 100%!

I notice that the slowness seems to be similar to the extremely bad performance I got prior to installing the NVIDIA drivers. I'm not sure if that helps.

This is the strangest part to me - although the temperature seems OK, even after rebooting, the system remains slow - starting with GRUB2 which is very noticeably delayed, all the way through to either Ubuntu or Windows! That's right, even the Windows side suffers effects and takes several minutes to complete booting whereas normally (with my SSD) it's ready to use in 15 seconds. The only way to fix it is to shutdown and let the parts cool down. Or maybe it just needs to completely power off and boot rather than a soft reboot, temperature has nothing to do with it? - is that possible?

But know that I have never had this problem in Windows, even if Windows gets very hot (135 F) a reboot would be enough time for it to recover. For this reason, I don't think it's a heat thing, but I can't imagine what else could be surviving the reboot.

I'm entirely updated - there are no pending updates. I have the Post-Release updates of NVIDIA too, btw.

If this sounds CLOSE to something you know about, but one of the details doesn't line up exactly, it might be a mistake in my perception. Are there tests you can suggest to rule something out?

Thanks!

processor   : 0
vendor_id   : GenuineIntel
cpu family  : 6
model       : 23
model name  : Intel(R) Core(TM)2 Duo CPU     T9500  @ 2.60GHz
stepping    : 6
microcode   : 0x60c
cpu MHz     : 800.000
cache size  : 6144 KB
physical id : 0
siblings    : 2
core id     : 0
cpu cores   : 2
apicid      : 0
initial apicid  : 0
fpu     : yes
fpu_exception   : yes
cpuid level : 10
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm ida dts tpr_shadow vnmi flexpriority
bogomips    : 5187.00
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

processor   : 1
vendor_id   : GenuineIntel
cpu family  : 6
model       : 23
model name  : Intel(R) Core(TM)2 Duo CPU     T9500  @ 2.60GHz
stepping    : 6
microcode   : 0x60c
cpu MHz     : 800.000
cache size  : 6144 KB
physical id : 0
siblings    : 2
core id     : 1
cpu cores   : 2
apicid      : 1
initial apicid  : 1
fpu     : yes
fpu_exception   : yes
cpuid level : 10
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm ida dts tpr_shadow vnmi flexpriority
bogomips    : 5186.94
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

(Redundant figures removed. You can view them in the edits if they are still relevant)

ps:

%CPU   PID USER     COMMAND
 9.4  2399 jason    gnome-terminal
 6.2  2408 jason    bash
17.3  1117 root     /usr/bin/X :0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch -background none
13.7  1667 jason    compiz
 1.3  1960 jason    /usr/lib/unity/unity-panel-service
 1.3  1697 jason    python /usr/bin/jupiter
 0.9  1964 jason    /usr/lib/indicator-appmenu/hud-service
 0.6  1689 jason    nautilus -n
 0.4  1458 jason    //bin/dbus-daemon --fork --print-pid 5 --print-address 7 --session

I should highlight specifically that GRUB2 can also be very slow. I don't know the relationship of which scenarios GRUB2 is also slow, but WHEN it is slow, it is slow both before the menu appears and after the selection is made - although for the diagnosis of GRUB2 it is harder for me to tell what the normal speeds should be. With SSD, I would expect that GRUB2 could load instantly, and that the GRUB2 purple would disappear instantly after the selection. The only delay to be expected is the change in graphics modes (though I couldn't guess why that ever requires any noticeable time)