AndyC said:

You're probably seeing the results of Core Parking. Windows 7 will power down cores to save energy when it isn't busy enough to utilize them.

ManipUni said:

You planning to get some more ram for that machine? Seems a shame to have a quad core CPU but have it be bottlenecked by only 2 GB of  ram.

sushovande said:

ManipUni said:

*snip*

Well, I really wanted a 32 bit system (so as not to be bugged with driver issues), so I knew my useful limit was 3GB. I thought that systems handle 2-way symmetrical RAM configurations better than assymetric (2GB+1GB) cases. What I did not know was that this particular CPU+Motherboard combo was optimized not only for the dual channel case, but also for the triple-channel case, so ideally I should have got 3GB (1+1+1 GB).

For now, I will postpone getting more RAM till I take the plunge into 64 bit.

sushovande said:

AndyC said:

*snip*

Thanks... it really might be core parking. Just watched the video of Mark Russinovich, and it says that Windows 7 has support for 256 processors (and I have a measly , and Core Parking even knows which cores are on the same die so that it can power down the entire socket.. In short, I am now sure Win7 does a great job running on my Core i7

ZippyV said:

sushovande said:

*snip*

Why don't you download 7-zip and let us know what your benchmark result is. (menu Tools -> Benchmark -> Dictionary size 32MB)
My quadcore gets a result of:

Intel Core 2 Extreme 2.6 GHz

CPU Usage	Rating/Usage	Rating
287 %	2151 MIPS	6571 MIPS

sushovande said:

ZippyV said:

*snip*

7-zip benchmark. What do the columns mean?

CPU Usage                Rating/Usage           Rating
505%                          2180 MIPS                   11013 MIPS

sushovande said:

AndyC said:

*snip*

Thanks... it really might be core parking. Just watched the video of Mark Russinovich, and it says that Windows 7 has support for 256 processors (and I have a measly , and Core Parking even knows which cores are on the same die so that it can power down the entire socket.. In short, I am now sure Win7 does a great job running on my Core i7

A second note, I'm not sure what program you were using to test the cpu, but if it was a .net program using the thread pool, it will only ever get 50% of the total load at that time, due to thread fairness in win7 with .net 4.

QuickC said:

After countless programs to test CPU verse real and hyper threads on my i7, All EIGHT cores on WIN7 x64 are real and contribute evenly to speed of a single application asking for 8 ore more threads (not the tread pool).  Excessive locking (kernal time) will slow the hyperthreadsto about 10% with the real threads at 90-100%.

 

A second note, I'm not sure what program you were using to test the cpu, but if it was a .net program using the thread pool, it will only ever get 50% of the total load at that time, due to thread fairness in win7 with .net 4.

Pretty sure Windows 7 can distinguish HT cores from real cores. Perhaps that is why 4 are unused.

http://www.tomshardware.com/news/windows-hyperthreading-intel-nehalem-atom,7831.html

sushovande said:

ManipUni said:

*snip*

Well, I really wanted a 32 bit system (so as not to be bugged with driver issues), so I knew my useful limit was 3GB. I thought that systems handle 2-way symmetrical RAM configurations better than assymetric (2GB+1GB) cases. What I did not know was that this particular CPU+Motherboard combo was optimized not only for the dual channel case, but also for the triple-channel case, so ideally I should have got 3GB (1+1+1 GB).

For now, I will postpone getting more RAM till I take the plunge into 64 bit.

What driver issues? How old is the rest of your hardware?

intelman said:

QuickC said:

*snip*

Pretty sure Windows 7 can distinguish HT cores from real cores. Perhaps that is why 4 are unused.

http://www.tomshardware.com/news/windows-hyperthreading-intel-nehalem-atom,7831.html

WIn 7 is surely tuned for Hyper threading, there is no real and hyper cores however.  Each cpu has two threads of code being feed it.  The cpu then looks for stalls, memory read, FPU process, or and answer from another cpu, when it finds a stall it switches to the other thread of code to keep the cpu 100% filled with instructions.

Keep in mind on a 3ghz machine, reading a memory location that isnt in the cpu cache could take 20-100 cycles of the cpu, if the memory has been written to virtual memory it could take 1000-10000 cycles before it can get back to work.

Also, before win7, each spoftware thread was tightly coupled to a particula core, that coupling can be loose between to hyper cores.

sushovande said:

ManipUni said:

*snip*

Well, I really wanted a 32 bit system (so as not to be bugged with driver issues), so I knew my useful limit was 3GB. I thought that systems handle 2-way symmetrical RAM configurations better than assymetric (2GB+1GB) cases. What I did not know was that this particular CPU+Motherboard combo was optimized not only for the dual channel case, but also for the triple-channel case, so ideally I should have got 3GB (1+1+1 GB).

For now, I will postpone getting more RAM till I take the plunge into 64 bit.

There aren't really driver issues anymore though.  Plus every OEM that ships Core i7 machines, desktop or laptop is sticking 64-bit Windows on them and I imagine the trend will continue with the Arrandales next year.

blowdart said:

sushovande said:

*snip*

What driver issues? How old is the rest of your hardware?

[This thread is a necro from January]

I still see some people struggling with the shift to 64 bit, so I didn't want to take the plunge. For example, a friend of mine wasn't able to get Eclipse working, because her Java was 64-bit but the Eclipse she got was 32-bit. I have seen people have issues with VPN as well, which would have been problematic for me.

sushovande said:

blowdart said:

*snip*

[This thread is a necro from January]

 

I still see some people struggling with the shift to 64 bit, so I didn't want to take the plunge. For example, a friend of mine wasn't able to get Eclipse working, because her Java was 64-bit but the Eclipse she got was 32-bit. I have seen people have issues with VPN as well, which would have been problematic for me.

Take the plunge.  I'm on an AMD 4-core Phenom II @ 3.4 GHz and I frikkin love X64.  I was kind of worried about compatibility with drivers and such, but so far, the only thing that doesn't work well is:

Juice: I couldn't find a better podcast program

IOmega's drivers for a terrabyte NAS.  Luckily, Win 7 recognizes the paths natively, so no big loss.

Start -> Msconfig ................

unchek ALL

Dovella said:

PS try this solution

 

Start -> Msconfig ................

 

 

unchek ALL

That's a bad idea. Windows automatically detects the number of cores and can use 256 at once. If Windows doesn't use all 8 cores under load situations, that's a BIOS issue. Intel Core iX and Xeon 5500 CPUs disable cores to save power and turn them back on when needed. This however requires BIOS and operating system support. Using the BIOS, power capping can be forced to do all kinds of funny things, though. Usually you'll find relevant options there.

You shouldn't change the kernel options from the defaults, that may have funny results. If for whatever reason those options were set, there should have been a reason for it, even if unchacked is the default.

Dodo said:

Dovella said:

*snip*

That's a bad idea. Windows automatically detects the number of cores and can use 256 at once. If Windows doesn't use all 8 cores under load situations, that's a BIOS issue. Intel Core iX and Xeon 5500 CPUs disable cores to save power and turn them back on when needed. This however requires BIOS and operating system support. Using the BIOS, power capping can be forced to do all kinds of funny things, though. Usually you'll find relevant options there.

You shouldn't change the kernel options from the defaults, that may have funny results. If for whatever reason those options were set, there should have been a reason for it, even if unchacked is the default.

You didn't read his advice.

Dovella said:

PS try this solution

 

Start -> Msconfig ................

 

 

unchek ALL

Thanks for the tip Dovella, but that suggestion is for boot time only. I was wondering about normal execution after boot. And they were already unchecked from the beginning, I did not change that.

I would like to reiterate that I find all my cores work to full capacity when the CPU gets busy, so Windows is doing things right already. I was merely curious why Windows chose to keep some specific cores idle. For example, in Ubuntu under very light load, I find that 2 cores are being used at any given time, and it cycles in a round-robin manner.

ScanIAm said:

sushovande said:

*snip*

Take the plunge.  I'm on an AMD 4-core Phenom II @ 3.4 GHz and I frikkin love X64.  I was kind of worried about compatibility with drivers and such, but so far, the only thing that doesn't work well is:

 

Juice: I couldn't find a better podcast program

IOmega's drivers for a terrabyte NAS.  Luckily, Win 7 recognizes the paths natively, so no big loss.

 

 

uhm UPnP, why do you need drivers for NAS?

sushovande said:

Dovella said:

*snip*

Thanks for the tip Dovella, but that suggestion is for boot time only. I was wondering about normal execution after boot. And they were already unchecked from the beginning, I did not change that.

 

I would like to reiterate that I find all my cores work to full capacity when the CPU gets busy, so Windows is doing things right already. I was merely curious why Windows chose to keep some specific cores idle. For example, in Ubuntu under very light load, I find that 2 cores are being used at any given time, and it cycles in a round-robin manner.

Well... as mentioned before Windows might do core parking. This means that the cores are shut down and power is saved. In my opinion that's an ideal behaviour because why would you keep all cores powered up if you only need a subset of them because of not much really going on?

sushovande said:

Dovella said:

*snip*

Thanks for the tip Dovella, but that suggestion is for boot time only. I was wondering about normal execution after boot. And they were already unchecked from the beginning, I did not change that.

 

I would like to reiterate that I find all my cores work to full capacity when the CPU gets busy, so Windows is doing things right already. I was merely curious why Windows chose to keep some specific cores idle. For example, in Ubuntu under very light load, I find that 2 cores are being used at any given time, and it cycles in a round-robin manner.

no, sorry, perhaps I expressed myself badly.
This is a bug in Windows 7

You have to deselect everything.

see here

Dovella said:

sushovande said:

*snip*

no, sorry, perhaps I expressed myself badly.
This is a bug in Windows 7

 

You have to deselect everything.

see here

The thread you just linked to has nothing to do with this problem. In that thread the guy didn't reinstall Windows so he was still using a uniprocessor HAL. That isn't a bug either.

sushovande said:

ZippyV said:

*snip*

7-zip benchmark. What do the columns mean?

CPU Usage                Rating/Usage           Rating
505%                          2180 MIPS                   11013 MIPS

The results seem low for an i7 920 i am running the same processor and i got with the system busy at the time of testing

CPU Usage                Rating/Usage           Rating
635%                          2499 MIPS                   15860 MIPS

Running Windows 7 x64 and 12GB RAM

TOTAL can be equal to 1 to 64

Try 9 threads on an 8 core machine, seven run at the same speed, and two run at one-half

Try 4 threads then 5 threads.... the scaling is exactly linear right from 1 to 8

Imports System
Imports System.Threading
Imports System.Threading.Tasks

Module Module12
    Private TOTAL As Integer = 8 - 1   'array size = number of threads starting a zero (ex. 8-1 = 8threads)
    Private ClassThreadHolders(TOTAL) As LoopThread 'array of classes
    Private ThreadArray(TOTAL) As Thread      'array of threads
    Private TotalAccumIncs As Long
    Private AccumIncs As Integer

    <MTAThread()>
    Sub Main()
        Dim n As Integer = 0                  'local loop var used in fors
        Dim ThreadPrintLoop As New Thread(AddressOf PrintLoop)

        Console.WriteLine("Building threads...")
        For n = 0 To TOTAL                                      'for each thread
            ClassThreadHolders(n) = New LoopThread                            'assign the class
            ThreadArray(n) = New Thread(AddressOf ClassThreadHolders(n).ActualThread) 'assign the pointer to the thread function
        Next

        Console.WriteLine("starting threads...")
        For n = 0 To TOTAL          'for each thread
            ThreadArray(n).Start()          'start the thread
        Next

        Console.WriteLine("Starting Printloop...")
        ThreadPrintLoop.Start()                'start printing thread

        Console.WriteLine("Waiting for keypress...")
        Console.ReadKey()                       'wait for key
        End                                     'orderly shutdown
    End Sub

    Private Sub PrintLoop()    'thread to print data on
        Do                      'infinite loop of thread
            Thread.Sleep(1000)    'sleep 1000 = 1 sec delay
            For j As Integer = 0 To TOTAL      'for each thread
                ClassThreadHolders(j).Grab()    'force the grab
            Next
            TotalAccumIncs = 0

            Console.Clear()
            For j As Integer = 0 To TOTAL
                AccumIncs = ClassThreadHolders(j).GetGrabbed
                TotalAccumIncs += AccumIncs
                Console.Write(Format(AccumIncs, "000,000,000,000     "))
            Next
            Console.Write(vbCrLf + Format(TotalAccumIncs, "000,000,000,000     "))
        Loop
    End Sub

    Public Class LoopThread         'need a class to have a pointer to a function that can be arrayed
        Private GrabbedInc As Integer
        Private Inc As Integer = 1    'class var must be fully declared
        Private GrabFlag As Boolean
        Private num As Double = 10
        Private num2 As Double = 5

        Public Sub ActualThread()         'sub on the thread
            Do                              'infinite loop of thread
                If GrabFlag = True Then
                    GrabFlag = False
                    GrabbedInc = Inc
                    Inc = 0
                End If
                'num = num * num2 / 50
                Inc += 1
            Loop
        End Sub

        Sub Grab()
            GrabFlag = True
        End Sub

        Public ReadOnly Property GetGrabbed() As Integer
            Get
                Return GrabbedInc
            End Get
        End Property

    End Class

End Module

Only real driver issue I had was a driver from a USB wifi adapter that was pretty old.  While I'm not thrilled when it effects me, I do understand when hardware makers do stuff like that.  There is a cost for making and supporting.