Precision T5400 Multiprocessor_configuration_not_supported in 64-bit Vista / Windows 7

Which version of Windows are you trying to install?

With Windows desktop OSes only the business or higher versions support dual processor. So for XP you need XP Pro (I'm not sure if XP Media Center will accept dual processor; it's marketed as a home OS, but has several features that the Pro version has (e.g. user-based file sharing)), for Vista you need Business or Ultimate, and for Windows 7 you need Pro or Ultimate.

I've got the same issue (with 2008 server SP2). It seems this issue is due to microcode or stepping differences between the CPUs even though use of CPUs with different microcode/stepping should be supported as long as they have the same specs otherwise (see this thread http://social.answers.microsoft.com/Forums/en-US/vistainstall/thread/5c2f8f77-e014-4ced-9b47-320b77a19f8b/). If you take the 2nd processor out it should work (Win7/2008 x64).

It looks like this issue is generally resolved by applying a system BIOS update (provided by DELL in our case). I'm at A05 (the most recent for the T5400), anyone know if there's anyway of finding out if this will be addressed in an upcoming update? Until then we'll be stuck running one CPU (or an older OS).

Dell just released a new BIOS A06 dated March 2010 and it still does not fix the problem. 

We are running Windows 7 Enterprise and it seems to work with two quad core Xeon processors.

MADCOW9597:

I have a t5400 with two same processor "xeon E5450(but with differental step, one processor is "A", the other one is "6". this is the major reason which cause window 7 64 bit can't been install). I have tried what you did, and I can repeat your case. But the issue is that You only can get 2 core running(even less than one process case). In order to get 8 core run, you need go back to msconfig again to un-check processor box as intel suggested. But once you un-check the box, window will ask you to restart the computer, again you will get the blue-screen.

That check box refers to physical hardware. You only have 2 processors physically in your system. The cores makes no difference. I leave mine at 2 and my system performs beautifully.

MADCOW9597,

How many core does you processor have? Have you test your computer?

I have windows xp 64 bit, I use window task manager to check, I got 8 cores are running, and the same machine, if I install window 7 32 bit, and I watch task manager, I still can see 8 cores are running. In window 7 32 bit case, I use "msconfig" to check. I found the processor box is un-checked. I have a program which can load 8 core, the xp 64 bit is much faster than window 7 64 bit(I believe it has only 2 core running although there are two processor and 8 core present in this system).

For what it's worth, a T5400 can run dual quad X5460 processors and have all 8 cores running on Windows 7 x64 Ultimate.  I have that configuation myself.  Fastest computer I have ever used.

-Noel

Noel,

My case is a little bit different. one of my cpu come from dell, the other one I bought from market, although both cpu is same. but there is still a parameter difference. The parameter is called "step", If I use program-accessories-system tool-system information. one processor shows" EM64T Family 6 Model 23 Stepping 6 GenuineIntel~2993Mhz", the other processor shows"EM64T Family 6 Model 23 Stepping 10 GenuineIntel~2993Mhz"

Could please check your cpus are exactly same or different. If your case is same as mine, my will upgrade my window7x64 professional to Ultimate.

Thanks!

Hi Tianyun,

Mine are both identical, Stepping: 6.

-Noel

Multi processors must be Matched pairs.

You cant have mixed steppings etc.

I may have found the solution...  at least it worked for me.

I have a T5400 with 2xE5405 quad core processors (stepping A & 6) running VMWare ESX 4.0 with several VM's and have been getting the same error when trying to configure a 64-bit Windows 7 or Server 2008R2 guest maching with 2 processors.

I had 22GB of RAM and was wanting to increase performance so I looked at the memory config and the Dell site and found this link:

<ADMIN NOTE: Broken link has been removed from this post by Dell>  

Here, it describes that the memory must be installed in pairs and for maximum performance, installed in banks of 4.  I looked at my memory config and found that in dimm slots 1-4 (white) I have all 4GB dimms.  In slots 5-6 (black) I had 2GB dimms and in slots 7-8 (black) I had 512MB dimms.

I removed the 2GB and 512MB dimms and saw a performance increase but no luck with the second processor.  Then I bought 2 more 2GB dimms from ebay and put them into slots 5-8 with the 2 that I had already.  Now, I have 24GB of ram configured as 4x4GB dimms in slots 1-4 and 4x2GB dimms in slots 5-8.

Now, ALL of my guest systems have 2 processors and my performance is greatly increased.

Yes, the system kicks the RAM access up to Quad Channel mode when the sets of 4 DIMMs match.

-Noel