core i7 in task manager - only 4 cores showing

[jt256]

Just installed win 7 64 bit on my core i7 system to see what it's like.

noticed in task manager I no longer see 8 active cpu graphs. well, there are still 8 boxes, but boxes 2 4 6 and 8 show no activity.

In xp and win7 32 bit all 8 graphs showed activity. I know it's a quad core chip with hyperthreading or something to bring it up to 8 cores, but I'm just wondering if I should be worried that only 4 of mine are registering in task manager under 64 bit.

Can anyone else with 64bit OS tell me if they've got 8 readings?

Thanks

[Ph4ZeD]

Just to correct you there mate, you have a quad-core chip, which most definitely only has 4 cores. Hyper-threading allows the chip to run 2 threads per core. It really doesnt matter that its only showing the 4 cores as the thing that really matters is the load on each core.

[Ben @ Scan]

Hi

Press Windows Key and R and Type Msconfig, Goto Boot.ini Tab and Then click advanced
Set /NUMPROC= to the maximum
Ok and restart the system

Open Task manager when back in windows and run Prime 95 to see if all cores are being accessed, if you have Turbo mode enabled and the system is idling it may use minimum cores

Regards

Ben

[jt256]

Thanks Ben, I had a fiddle with the advanced settings in msconfig, and then took them off again.

When I ran a quick performance test I noticed that all 8 virtual cores did spring to life. Under win 7 32 all 8 were always on the move, even at idle, but it seems with win7 64 the virtual cores only kick in when needed.

Ph4ZeD, thanks for your input, but I don't recall questioning that my quad core chip has 4 cores. I do however have 6 months experience of win7 32 and I recall with crystal clarity that in task manager when I run a big job all 8 (real and virtual) cores show activity. That's why I was a bit worried to see only 4 active out of 8 total. Because that didn't happen in win 7 32. If someknow knows whether 64bit handles cores differently I'd be grateful to know. thanks

[NightOwl]

Just so you know; I have Windows 7 Professional 64-bit and a Core-i7 CPU (been using 64-bit Win 7 since March, various builds, now the final retail release)... task manager has always shown 8 CPUs. Even when the load is light the unused ones show "flat line" activity on the graph.

I don't know why yours should be different - I've installed this OS several times since March and have never seen anything other than 8 graphs.

[Terbinator]

If it happens again make sure you have Hyperthreading turned on in your BIOS.

[jt256]

Well this is good to know, so I'm not as stupid as some would make out...

Mine is the release version of windows 7 pro, all legit and whatnot.

When I work it hard the 'silent' cores spring into life, well 7 of them at least. My bios ht settings are unchanged, and all look OK, so I wonder what's going on!

[Terbinator]

My i7 860 doesn't turn off cores to save power - but it does feature agressive 'Speed-Step' settings which clock it to around 1200MHz when im not doing anything. It appears your 'problem' is unique, but your saving the planet, right ?

[eric_lord]

I have the same issue. I recently upgraded my Core i7 PC from Windows Vista (x64) to Windows 7 (x64). When I had Vista in stalled in Task Manager all 8 CPU's showed relatively the same usage all the time. It was balanced accross all 4 Physical CPUs and the the 4 Hyperthreaded virtual CPUs. However, after upgrading to Windows 7 I now see even activity on CPUs 1, 3, 5 and 7 and virtually no activity on CPUs 2, 4, 6 and 8.

I read a few articles explaining that Windows 7 made several new advancements in the area of Hyperthreaded CPUs probably due to Intel renewing the technology in the Core i7. This perceived performance issue could be by design and I expect Windows 7 should out perform Windows Vista in all respects.

When I ran a performance test (basically, I reassessed my computer's "Base Score") I only saw the Hyperthreaded CPUs spike up evenly during the "Processor Test".

All that being said, I do have a few performance issues with Windows Media Center on Windows 7. Most forums I've read attribute it to NVidia's GPU drivers. I'm still on the fence with this issue.

[jt256]

Interesting. I've noticed that over time the OS swaps which cores idle, and which do minimal work. I haven't yet probed the threshold at which all 8 kick in, but they certainly do all fire to life when needed. So I'm reasonably reassured that it's a power management thing.

My throttling settings are in advanced power settings, and I use an excellent program called core temp to track the temps and frequency of my cpu. It goes up and down all the time, as required.