# E8400 Using Only One Core



## grumpyuncle (Jun 24, 2008)

Sorry for long post but I am trying to be as thorough as possible. I have a new machine that has been plagued with problems.
Sytem Specs
e8400 Intel
2 8800 Superclocked Evga cards
Evga 750i
4 gigs OCZ Reaper 1066
Corsair 750w PSU
2 90gx2 Monitors 19" 1280 x 1024
Win Xp 32
(Everything is stock. No overclock)
Quick back story of my problem. My computer becomes choppy when I play games for more than a minute or two. System ran great for 3 weeks and then one day I was playing COD4 and it seemed very choppy. Regular video plays fine but as soon as I'm in game and my laser mouse begins to move around a lot the game gets choppy. In the last 2 months I have reloaded xp, tested memory, loaded old and new drivers and tried different monitors. Thought it had to be the PSU but it reads fine in bios and volt meter checks out fine. EVGA tech support thought it could be a bad mobo but swapping it did not help. About 2 weeks ago I ran OCCT stress checker on my CPU and it would only go a minute before it crashed. CPU would raise 20 c with stock heat sink. Voltages all read fine and I have 3 case fans and 2 pci slot fans as well as the mobo, cpu, and video card fans so I couldn't figure that out why it would overheat. I put on a aftermarket heatsink (vendetta 2) and this time the test went 30 minute only raising 10 c the whole time. I also ran prime 95 for around 9 hours everything passed. The choppiness remained with the new cooling. Now EVGA tech support told told me to send in both my video cards in. Both cards were 7 months apart so I could not understand how how they both went bad. But I submitted an RMA on them because they played a little choppy when I put them in my old machine . Made sense. Later that night I was on my computer moving a window out of my way on screen when and noticed it was streaking. I figured it was my cards acting up but I checked task manager and saw cpu usage was going up to 100%. The only thing I had running at the time was x-fire, firefox, and task manger. My CPU usage under that circumstance should only be around 15% . I could find no extra processes running. Besides it was a fresh install and I have very little software loaded on my machine. It did some system checking and now it seems my system is now only using one core. I checked the bios and they were enabled. I checked hardware device and they both show up. But run any system monitor and only one core is reported when they always read 2 before. I tried to enable in boot up but only one core is an option. Prime 95 only is checking one core as well.
My question is could I have always had a bad core? If not, what would cause a core to malfunction suddenly like that? I only ran Prime 95 a couple days ago again and it reported no errors. Could this have been tied in with that overheating in the beginning? Any ideas would be appreciated. 
Thanks
Grump:4-dontkno


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## OMGmissinglink (Sep 24, 2006)

Download CPUZ .. post if it show both cores.
http://www.cpuid.com/

Download Core Temp.. post does it show temps on both cores?

http://www.alcpu.com/CoreTemp/


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## grumpyuncle (Jun 24, 2008)

Thanks for the reply. No Real Temp. Nvidia Sytem Montior, Core Temp, and CPUZ all read only one core. They always read 2 before yesterday.


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## OMGmissinglink (Sep 24, 2006)

Oh so you downloaded them under 2 minutes and checked just now?


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## grumpyuncle (Jun 24, 2008)

Yes I'm sitting at my machine. I have those programs already loaded after last night so I checked them again.


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## OMGmissinglink (Sep 24, 2006)

in device manager under processors does it show 2 processors?


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## OMGmissinglink (Sep 24, 2006)

This is an issue:
4 gigs OCZ Reaper, Win Xp 32bit

32bit windows does not play with 4gb ram installed .. 3gb ram total


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## grumpyuncle (Jun 24, 2008)

Yes it does. I tried to enable it but no go. Everything else shows there is only one core. Window task manager is even only showing one graph in performance when it always had two.


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## OMGmissinglink (Sep 24, 2006)

Power off your pc, remove 2gb's ram

boot into safe mode uninstall processors in device manager, reboot pc ... post if both CPU's show in device manager.


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## grumpyuncle (Jun 24, 2008)

Thanks. I meant to say device manager is showing 2 cores are installed and are working properly. Everything else says no. Give me 15 minutes or so and I'll let you know.


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## OMGmissinglink (Sep 24, 2006)

Open core temp you should see cpu load switching between cores.


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## grumpyuncle (Jun 24, 2008)

Core temp only shows 1 core and one thread. Cpu 0


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## Pharaohz (May 10, 2008)

Mine shows 3.5 gigs of ram out of 4 

Say heres a question... With dual channel and hyperthreading, would they work better (if there is a better or if they just work) with just the 2 gigs (2x 1gb modules) or does it work as it should with the 4 x 1gb modules only showing up at 3.5? Both DC and HT show up as working and enabled with the 4 x 1gb modules showing up at 3.5 and the performance boost is very noticable over no DC/HT. 

lol i guess I coulda just made a thread for this question... sorry


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## OMGmissinglink (Sep 24, 2006)

Does your mobo's current bio's ver. support dual cores?

Solving 4gb issues under 32bit OS 2x 1gb w/ 2x 512gb dimms


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## grumpyuncle (Jun 24, 2008)

I took out 2 gigs uninstalled in safe mode and reloaded. The device manager still shows 2 cpus enabled but everyhting else shows only one cpu. Task manager again as well.


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## grumpyuncle (Jun 24, 2008)

Yes its a new board the Evga 750i Ftw which supports all the latest Intel chips.


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## OMGmissinglink (Sep 24, 2006)

Contact EVGA ask if the current bios' version supports E8400 processors.

888-881-EVGA (3842)


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## grumpyuncle (Jun 24, 2008)

I appreciate you trying to help me sort this out. It supports all the new 45mm core 2 duo chips which includes the e8400.


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## OMGmissinglink (Sep 24, 2006)

grumpyuncle said:


> I appreciate you trying to help me sort this out. It supports all the new 45mm core 2 duo chips which includes the e8400.


Did EVGA support tell you the mobo does? most mobo's say they support the latest cpu's but thats usually after a bios update.


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## grumpyuncle (Jun 24, 2008)

Just got off the phone with tech support and yes the board does support my chip. He said I needed to try a windows repair so I am going to give that a shot. I will let you know how that goes.


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## OMGmissinglink (Sep 24, 2006)

Did you replace the thermal paste on the HSF or use thermal pad on the HSF?


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## Pharaohz (May 10, 2008)

I just flash upon this. If you have hyper threading enabled then it will show two cpus in device manager. If you disable hyper threading it will only show one then. At least this is the way it works with P4 478s. Enter bios and turn it off if its on and then check DM. This will not fix your problem but may add more weight to it.


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## OMGmissinglink (Sep 24, 2006)

Doubt repair install will fix this ...


1. Check in bios is MPS enabled or disabled? switch settings then check with core temp if both cores show swaping between cores.

2. Another possible cause is bent cpu pins / or foreign material in the socket on the mobo.

http://www.pcstats.com/articleview.cfm?articleid=2231&page=2

3. You've overheated the cpu do to improper thermal paste applied.


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## grumpyuncle (Jun 24, 2008)

Thanks for trying to help me OMGmissinglink. Repair actually fixed this problem. The machine is now reading a second core after repairing windows. As for the original overheating problem , Intel fans come with thermal paste strips already applied to the fan and the chip was getting hot pretty quick. I did remove the fan (which you could see had a good amount of thermal paste on it and the chip), cleaned it, and put arctic silver on it and it still kept getting hot quickly when under stress. Since I put the after market cooler on the cpu has remained between 30c idle and 46c under stress. Now if I could figure out why my games are getting choppy I would be a happy man.

Update:
Just read over in Tom's Hardware forum that other people are having problems with the stock heat sink for the 775 socket. Apparently they aren't designed very well.


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## OMGmissinglink (Sep 24, 2006)

Rapair install fixed it ^Kudo's, never use stock HSF's & thermal pads on Hi end cpu's


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