Silly question, but did you update to the latest bios?

It's A06 now. It was A03 before. I flashed the BIOS before changing the CPU. 

 

 

Did you clean and reapply the thermal paste?

Did you double check to make sure all the connectios are seated correctly. 

You might want to either try doing a CMOS reset after first taking note of your current bios settings. 

Or you try dopping in the old processor to see if that one agains run correctly. 

You system should run the E8400 with Bios A06 installed.

 

 

 

 

 

 

 

 

 

 

 

 

 

Thanks for the input. I have tried several things so far.

 

I applied new thermal paste. In fact, I put too much at the first time and had to wipe off the extra.

 

I thought it has to be some kind of setting problem. If I put the old chip back, it runs normal. Once new CPU is there, the CPU fan runs at 100% and never goes down. I have switched a few times and it always like this. Besides the cpu temp is not high at all. 

 

I was thinking some bios setting but apparently there is no adjustment for fan setting in dell's bios. I did CMOS reset when new chip is there and it didn't help.

 

I am running of ideas now. I really like to have a fast CPU and I can't live with fan spinning at 100% all the time.

Just called Dell XPS tech support, and was told that it's not supporting CPU with 6MB L2 Cache??? Because they wanted me to run diagnositc during reboot and it failed to run it saying it's not support the current processor.

 

I am getting confused here. Guys, does it sopport E8400 or not?

 

 

   nathanhusker,

I have an e8400 in one of mine and it runs fine.

Since there is no solutions for now, I decided to buy a quiet case fan and put it into the CPU fan hold. Might not be the best thing to do though.

I had the same problem as you.  I installed a new E8400 into my XPS 720 a couple of days ago. As soon as I powered on the system, the CPU fans would increase to 100% and never throttle down. I installed the A06 BIOS as soon as it was available.

I tried re-flashing the BIOS, cleaning and reapplying the thermal paste, and trying to adjust the fans through nTune.  None of these attempts made any difference.

I checked the chip’s temperature with RealTemp. RealTemp showed 35C for Core 0 and 30C for Core 1.  RealTemp also showed that Core 0’s sensors were stuck. 

 

After all this testing, I found your post and was disappointed to learn that not even clearing the CMOS helped.

I even called XPS tech support. The first tech told me the problem was that I was using an XPS 700 heatsink instead of an XPS 720 heatsink. I asked how this could possibly make a difference; reminding him that the fans were running at 100% on boot. He stumbled for words, and said the voltages between the two heat sinks were different.  Another tech concluded that both fans were bad, and I’ll need to get them replaced (and maybe the M/B too).  His system was down that night so he couldn’t dispatch the order, but promised to call back the following evening.  His call is now 38 hours overdue.

 

I removed the heatsink one last time, dropped in the E6600 and fired the computer up.  Fans worked perfectly. I’m thinking the problem lies with the 1333MHz FSB. 

I’m disappointed that I couldn’t get the chip and M/B to get along. I’m extremely disappointed in (and angry with) XPS technical support. Since there is no solution on the DCF board, I’m going to return the chip.  My apologies for the wall of text, but I hope that this will help anyone else that has this problem. 

nathanhusker, LupercalH,

We know that the XPS 720 nForce 680i SLI supports a 1333FSB since we validated these Dell processors -
Y934C Wolfdale Dual Core Kit, E8500, 3.16G, 6MB, 1333FSB, 65W, C0
Y935C Wolfdale Dual Core Kit, E8400, 3.00G, 6MB, 1333FSB, 65W, C0
PW016 Kentsfield Quad Core Kit, QX6850, 3.00G, 8MB, 1333FSB, G0
C864D Yorkfield Quad Core Kit, Q9450, 2.66G, 12MB, 1333FSB, C1
MP628 Conroe Kit, E6850, 3.00G, 4MB, 1333FSB, G0
MP162 Conroe Kit, E6750, 2.66G, 4MB, 1333FSB, G0
MP160 Conroe Kit, E6550, 2.33G, 4MB, 1333FSB

Were those Dell processors or retail ones you tried? I wonder if the retail specifications were the same as ours?
Y935C Wolfdale Dual Core Kit, E8400, 3.00G, 6MB, 1333FSB, 65W, C0

Chris,

 

I ordered mine from Amazon.  This is how it is listed: Intel BX80570E8400 3.0 GHz 6M L2 Cache 1333MHz FSB LGA775 Core 2 Duo E8400 Dual-Core Processor.  It was not OEM; it came in an Intel box with a heatsink.  I don't remember other users specifying whether their chips were retail or not.

 

Technical Details

 

The chip did work.  I was able to POST, get into windows, and even run some benchmarks without any lock-ups, BSODs, or restarts. The problem is trying to get the two 120mm fans to throttle down.  They run full speed on boot and never slow down. 

 

I was thinking that maybe the 1333MHz was conflicting with some setting that prevented the fans from powering down.  They work fine on my E6600.