Legit Reviews

Here's the link to the processor compatability chart for my motherboard
http://www.intel.com/design/motherbd/bz/bz_proc.htm

I'm wanting to buy a P4 extreme edition to give my old system a little boost, but the revision number on my board is C26680-205, which is one below the revision number they state you need to use most of the socket 478 processors. Is there any way to work around this? I have the latest bios installed if that helps at all.

my only guess is that earlier revisions didn't support the larger cache sizes present in the processors above that line. all below are 512 or smaller l2 and the ones above are 1mb - 2mb. which is partially why those processors are so much better.

hum... don't know some CPU's wouldnt work... Most all socket 478 processors will work on that board. As long as you have the most recent BIOS installed you should be good to go... Intel changes the revision number when a new BIOS is shipped on a board, so it might be something as minor as that.

Darn, so would you say that's a hardware issue and not something updated bios or something along those lines would take care of.

^^yeah, thats what I was thinking, that mine didn't support the higher caches originally, but with the latest bios it might. I'll defnitely wait for some more opinions before I do anything though.

I've got the highest P4 S-478 in my machine right now. It's a 3.0Ghz Northwood. This MSI 865P Neo board can't go any higher either.

I checked more than once on seeing if a higher S-478 would work, but by scanning around the internet, people had mentioned the same thing that MSI has stated ... No can do. So, I'm not going to choke, but OC some.

Even with the latest BIOS, it will not work.

I found this in the datasheet for the Pentium 4 extreme edition.

Intel 875P chipset - Chipset that supports DDR memory technology for the Pentium 4 processor with 512-KB L2 cache on 0.13 micron process. This chipset also supports the Pentium 4 processor Extreme Edition supporting Hyper-Threading Technology in platforms that meet the thermal design guidelines for this processor.

So that makes it seem to me that my revision might not meet their thermal design guidelines. Does that mean that it'll run just not at the ideal temperatures it runs at on later boards? I have a well ventilated case with a good heatsink. My current processor, a 2.8Ghz nortwood, idles around 30 degrees and hovers between 40 and 45 when I play supreme commander, a processor intensive game. So would I be safe running the 3.4 Ghz EE? I guess I could also be way off base and this has nothing to do with why they say my rev isn't compatible.

The later P4's were based on the Prescott core. They were 90nm, had 1mb of cache, ran at lower voltage and consumed alot more AMPS. The power circuitry on earlier skt478 boards didn't support these new Prescott chips.
They couldn't supply soo many AMPS with low Volts. This caused the mosfets and caps to die.

Some boards worked fine, even with the older power spec.
The ASUS P4C800 & P4P800 & Abit IC7 range worked fine, they just needed a little air over the CPU socket area to help when overclocking. I wouldn't try it with any other boards in case...

I have two Dell 400SC based on the i875 chipset.
One of the motherboards has a 2.26Ghz P4.
It is slightly different in design in that it only has 4 low voltage capacitors.

The other 400SC which is a 3.2Ghz P4, besides having a beefier heatsink has 6 low voltage capacitors around the CPU.

They are close to the same vintage (I ordered the 3.2GHz a few months before the 2.26Ghz, but this was many moons ago.)

Usually, what causes the MB not to work is the VRM (voltage regulator) can't support the voltage/current required by newer CPUs.

The only other thing I'd check is the Intel motherboard revision errata.
Intel will rev the version on BIOS updates, so it could be that all you need is a newer BIOS.