Can I use this CPU?

[xwhatsit]

Forgive me asking what might seem some very basic questions, but I've been Googling for a while and still don't quite understand.

I'm intending to set up a MythTV box, so bought a small-form-factor Acer system second-hand (it's an Acerpower SK30). All very well, but I want to juice up the processor a bit, as it has some P4 3GHz thing in it that I'm told tends to run quite hot.

Anyhow, Acer seems to have scrubbed most of its technical docs and specs for this old (~2006) PC off their site, so I can't find out much about the motherboard (E915GVM) in it. What I have grasped is that it's a 915GV chipset, which is socket LGA775 and has an FSB of 533MHz and 800MHz.

So I did some learnin' and at first glance it seems all I need to worry about is finding an LGA775 CPU with an FSB of 533MHz or 800MHz.

The Pentium E5800 seems like a good candidate, apparently low power and cool running. 800MHz FSB and LGA775. Cool.

Except now I read this new thing that apparently my mainboard BIOS might need to be updated to learn about new processors? What the! The E5800 came out in 2010, and the latest BIOS update I can find for the E915GVM is 2006.

Is this correct? So if I put an E5800 in this motherboard, it will just refuse to boot because it doesn't know what it is? Seems very odd!

[The Solutor]

P4 and Core Cpu have different architectures, so even if electrically compatible they requires  a suited bios to boot on the same MB, the Core architecture was s delivered in Q1 2006, so It's possible but  unlikely that the latest bios available is core ready.

it will just refuse to boot because it doesn't know what it is?

Many MB will boot even with newer processors than the officially supported ones, but they must be from the same architecture.

[xwhatsit]

Ah poos. Have specced up a new motherboard that I can fit into the case... given that I'm chucking nearly everything out, bit of a waste of money buying the thing in the first place. Could have got a cheap case and PSU!

[Pylon]

I highly doubt it. I have a Dell with a 965 chipset and it won't take 45nm Core 2s, so I highly doubt a 915 would take 45nm Core 2s at all.

[keyb_gr]

Not even a 955X will take Core series processors, actually. The reason was a shared core voltage supply for CPU and northbridge, IIRC.

[xwhatsit]

Man, computers are harder than I remembered them. This is why I stick to software and 8-bit µCs!

Ah well, pretty cheap to put a new motherboard in (ASRock with G41 chipset). Lets me use an E6600, too, which is slightly quicker and cheaper than the E5800.

[ch_123]

I'm almost certain that there are no (originally) P4/PD motherboards that take Core 2 Duos - differences in voltage regulation and chipsets prevent it. The other way around works though.

[The Solutor]

I'm almost certain that there are no (originally) P4/PD motherboards that take Core 2 Duos -

Many P4 MB were updated to support core CPUs

Like this http://www.asrock.com/mb/cpu.asp?Model=ConRoeXFire-eSATA2, BTW I believe that the chipset must be, at least, a 945 to be upgradeable via BIOS update.