CPU needs BIOS upgrade???

[zz]

Is it possible that a certain CPU would refuse to work in a PC unless the BIOS is upgraded?

[absic]

Hi there,

yes, there are instances where you need to have the latest BIOS to run the CPU, especially if the CPU is a new model.

You need to check the CPU support list for your motherboard for compatibility.

[Dark Mantis]

Sometimes it might even be a case of the board not supporting the CPU at all. You will certainly need an older supported chip to run the BIOS update assuming one is available.

[zz]

How can the BIOS (a program) make a difference unless the CPU is able to run it?

[Dark Mantis]

The BIOS (Basic In Out System) sits in between the motherboard and the CPU and it must recognise both to be able to work so if you introduce a part that is not recognised you have a problem.

Update the BIOS first and then install the new processor.

[zz]

How big can that problem be? As big as in making the PC play dead (no vga, kb, beeps)?

(maybe some other chip does some preliminary checks)

[Dark Mantis]

Trust me if your CPU is unsupported then the machine won't start properly. 

[nijel]

From my experience for Intel platforms Dark Mantis is right - it wont start.
For AMD platforms it boots with Unknown CPU Type message and let you update the bios. That was the case for the old AMDs. Not sure about most recent ones.

[Dark Mantis]

From my experience for Intel platforms Dark Mantis is right - it wont start.
For AMD platforms it boots with Unknown CPU Type message and let you update the bios. That was the case for the old AMDs. Not sure about most recent ones.

The newer AMD CPUs usually have the same response as  the Intel ones and an older supported CPU is required to run the update for the bIOS before the new processor can be installed.

[zz]

Terrible logic! My intel MSI does not even need a DIMM to start...

Least with your help it'll eventually start. Of course I'll have to buy the 3rd CPU for that, because I got no clue about its BIOS version.

The box says core2 compatible, but the S/N on the box is not found on the mobo!? So am I in for the oldest P4 just to update one BIOS...

[Dark Mantis]

Rather tahn purchase another CPU just to flash the BIOS why don't you take it to your local computer shop and ask them to do it. Normally they are happy to for a small payment.

[zz]

Wouldn't that be too simple? ;-)
I'm not sure that would work though: last CPU I tried was good for BIOS ver F2, which is the oldest in the compatible CPU list; on the other hand the manual has pictures with a ver F1 of BIOS ?!
So servicing the board may be the last resort. Board has a flicker left to it, as clearing the CMOS made a minute difference. There's an error code put on PCI which some chinese boards can retrieve. Yet I suspect a bad contact, at the main chip or the CPU socket, either the main chip gone alltogether. Any schematics out there?

[Dark Mantis]

Not a chance I'm afraid! I have tried in the past to get hold of schematics and detailed circuit diagrams etc but no luck.

[zz]

According to some other experts there are instances where a BIOS upgrade is only necessary to recognise a new CPU (ie system starts, but incorrect cpu ID)
In my case the 430 should have no problem as F2 BIOS is the oldest released to public. Not sure about the e3400 yet

[Dark Mantis]

I don't want to get into a discussion about the whys and wherefores of doing a BIOS flash but there are many times when it can help and if the chip is not supported more often than not the board will just refuse to start.