task manager performance tab show only one CPU core

[seahorser]

On the performance tab I remember that I see how many cores a CPU had by separate "CPU Usage History" columns (one graph for each core). Also on the View menu there is an item called "CPU History"->One Graph Per CPU.

My old XP and any new installations I make for that matter, even with different Hardware Abstraction Layer than ACPI (by pressing the F5 key early at text mode setup), all show one graph at CPU Usage History where my CPU isn't a single core CPU. How I get Task Manager like this ?

PS. I feel that I'm going loose on my memory :(

[ED_Sln]

What processor is installed? How many processors are visible in Device Manager? If the processor is exactly multi-core, then it is possible that all cores are disabled in the BIOS, except for one.

 

[seahorser]

Device manager shows one processor. The CPU is Core 2 Duo. I don't think my BIOS has the ability to disable cores. BIOS has:
Enhanced Halt State, Intel virtualization tech, CPU thermal throttling, Intel speedstep tech, No execute memory protection, Intel C-STATE options. I have try some combinations with enable and disable settings but windows still shows one processor on the Device Manager, whatever the Computer is ACPI multiprocessor PC or ACPI uniprocessor PC.

[ED_Sln]

On some motherboards, you can disable kernels for compatibility with Win 9x. Therefore, it is advisable to reset the BIOS, especially if one core shows even if ACPI multiprocessor PC.

Cores can also be disabled in msconfig, but by default everything is enabled there, so there should be no problem after reinstalling.

[seahorser]

Msconfig shows one CPU and the numproc value isn't in use (none of the options is in use). In fact I never use Msconfig. Occasionally I use autoruns. Also the new test installations I was saying in my first post didn't have any chance to run msconfig. This motherboard BIOS doesn't have the OS compatibility setting which had earlier motherboards. What you mean by reset the BIOS? Load default values or re-flash it again with the same BIOS version? If is that the case, that should mean that a very sophisticate BIOS level firmware is sitting there...

[seahorser]

Problem solved by reload default BIOS settings (F9 in this m/b) and suddenly 2 processors appear in device manager. The previous BIOS settings and the "new" reloaded defaults are the same as I double check them before and after!!!
Another mysterious aspect is that before the reload to defaults action, I had try to change the NoExecute memory protection and the Enhanced Halt State to Enable but then the XP stays forever in a blank screen so I have to press the hardware reset button. XP detect the reset and they boot to safe mode just fine, but then they won't boot to normal mode as long as BIOS NoExecute memory protection and Enhanced Halt State settings are enable. When I set them to disable XP boot as always with one processor available.

Probably ACPI BIOS got "corrupted" as described by Mark Shuttleworth at wikipedia's ACPI article.

Now with ACPI multiprocessor PC in the computer's device manager and the two performance columns in the task manager, wPrime benchmark needs half the time to finish when wPrime advanced settings is set to 2 threads. It even boot whatever the setting I have at NoExecute memory protection and Enhanced Halt State.

After 4 days of waste research the conclusion is that the defaults BIOS values are not internally equal as those I had seen on the screen, although they appear the same.

[ED_Sln]

12 hours ago, seahorser said:

Problem solved by reload default BIOS settings (F9 in this m/b) and suddenly 2 processors appear in device manager.

So there is still a setting somewhere that disables the second core.

[seahorser]

If it is exists and it isn't something else, like BIOS rootkit which control the other core individually from the OS by side channel, it must be hidden. There isn't any setting like this anywhere in the BIOS tabs. I can take pictures of the BIOS if you don't believe me.

[ED_Sln]

It is possible that the setting is hidden.

[Tripredacus]

Which HAL is installed? This shows up in Device Manager in the Computer section.

I have seen a wrong HAL in XP cause a MP appear as a UP in both Device Manager and Task Manager Performance tab.

https://www.betaarchive.com/wiki/index.php/Microsoft_KB_Archive/309283

[seahorser]

I didn't say otherwise! It was revert to UP. BIOS reported one processor on any clean XP 2003 etc. installation I was trying, so both Device Manager and Task Manager shows what they think they find. Also I was try to force install the MP HAL (also try all the other options it has that menu) using F5 key on a new XP setup, but again windows shows one core. The problem solved by reloading the BIOS default settings (although the settings are the same).

PS.
Some years ago I was see the following peculiar problem:
The PC doesn't POST and doesn't boot. Believing that the GPU had fail (from my previous experience with PCs I was thinking the capacitor plague issue), I replace it with another GPU and the PC POST/boot as usual. I then replace the new GPU with the old GPU and the PC, again, doesn't POST or boot. I was try many times add/remove memory DIMMs, changing PSU, keyboad etc. The PC by no god wasn't able to POST/boot with the old GPU. Then with the new GPU I reflash the BIOS from pure DOS. Then I install the old GPU again and the PC POST/boot as should be! Maybe that was the time it revert to UP, don't really know. Now I have the new GPU which is faster laying around because the old is fanless (although I had a small fan to keep it cooler in summer times).

[jaclaz]

As ED_SIn hinted, it is possible that the BIOS has a few settings (advanced) that are "hidden", i.e. are not visible in the BIOS pages.

If one of these is - for whatever reason - changed/corrupted this would justify the behaviour and a reset to default values would solve the issue by magic.

jaclaz

Edited September 26, 2020 by jaclaz