Why doesn't Win7 realize there is a dual core aboard?

[MikalE]

I did not know this. I have been wondering why this machine has been slow ever since I reloaded the OS way back late last year. I had been through the system and it is clean. Sparkling clean.

I come to find out that Win7 defaults to a single processor upon installation. How can it not know it is a dual core processor when it knows what it is in the System tab?

I had to go through the boot menu and enable the second core manually. This machine is now running like a dual core i7 machine should be.

That's asinine to have to do that manually.

[jdrou]

What "boot menu" are you referring to? If you mean the BIOS config that has nothing to do with Windows; if multi-core is disabled there nothing can use the second core. I've never had to do anything in Windows to use multiple cores (dozens of fresh installs on many machines).

[jronald]

Are you running 32 bit W7 or 64bit?

Ron

[MikalE]

64 bit. I get into the boot menu and check to see how many cores Win7 is seeing and the window has 1 displayed. I couldn't believe it.

I selected 2 and saved, backed out, restarted, and it was like a new system. PS, Google Earth, e-mail was opening in just a few seconds instead of 20-30 seconds I had been waiting since reloading this system late last year after a SSD upgrade and reload.

I checked my T510 and my T500 which both got new hard drives, and the T500 was upgraded to 7 from Vista business. Both only had a single core recognized.

All three machines are running like a top now.

[hhhd1]

I get into the boot menu and check to see how many cores Win7 is seeing and the window has 1 displayed. I couldn't believe it.

I selected 2 and saved,

how do you access the boot menu ? do you run 'msconfig' ?

what is the processor ? in case of the one in your signature, the 2620m, it should be listed as 4 processors due to HT.

[MikalE]

Yes. It's under Advanced Options.

I mis-spoke. It's not how many processors, but how many cores.

[jdrou]

When I look there it has no check mark in the box next to 'number of processors' which means 'don't limit me to less than the available cores'. Only if that box is checked would you be limited to one core (and on my dual-core i7 the dropdown goes up to 4 while it only goes to 2 on my non-HT Core 2 Duo so it's probably actually counting virtual rather than physical cores).

Was that box checked on your clean install of Windows?

[MikalE]

It was not checked. But if what you say is true how do you account for the increased performance after selecting 2 cores?

It was the same for this machine and an i5 T510 I have. Up to four cores for selection. The T500 was listed as having only two selections. For a Core 2 Duo processor.

[jdrou]

It was not checked. But if what you say is true how do you account for the increased performance after selecting 2 cores?

You'd need more detailed measurements to say there was increased performance. More likely something else changed.

It was the same for this machine and an i5 T510 I have. Up to four cores for selection. The T500 was listed as having only two selections. For a Core 2 Duo processor.

As I mentioned, it seems to include the 'virtual' cores created by Hyperthreading. Core 2 Duo doesn't have HT while i3/i5/i7 does.

You should also be able to see how many cores are enabled by looking at the 'performance' tab in Task Manager. There's a separate 'CPU usage history' graph for each physical or virtual core. Try unchecking the box and then reboot and check the Task Manager.