Confusion on older Pentium 4 CPUs

[Joony]

I'm an AMD fanboy and I don't really follow up on P4s much...

I have a computer with a dead 1.5ghz P4 in it and i'm just looking at suitable replacements.

First question, for something like a P4 1.6a, what does the letter a designate?

2nd, the willamette and northwood core both came in socket 478 form?

 

[Blain]

Both Willamette and Northwood cores come in the 478pin flavor.
The Willamette cores have a 256kb cache while the Northwood comes with 512kb & 2mb.

On older P4's, I believe the "A" designates a Northwood 400MHz CPU.

Your MB is the key issue in what CPU you can go with.

 

[oldfart]

I think....(not 100% sure), the P4 1.5 was S423. If so, you need a S423 chip or a S423 -> S478 converter

 

[Stormgiant]

Look at Intel Site...

 

[Blain]

Yes, they came in both flavors

 

[PacFu]

x.xGHZa = 400 MHz bus
b = 533
c = 800 MHz
e = 800 MHz w/1MB cache (prescott)

 

[CJP]

If you've got a socket 478 motherboard the fastest cpu you can get at stock speeds is 2.6ghz. You could possibly overclock to 533 mhz and get a maximum of 3.06ghz depending on your motherboard.

I upgraded from a 1.8a to a 2.6a (400fsb) and it's good for current (except far cry) and older games but I don't think it'll be great for Doom 3 or Half-Life 2. Windows is a bit snappier though.

 

[Oyeve]

Then there is the P4 XE chip with 2mb L3 cache which is an 800fsb and still Northwood and a big waste of moola, IMO.

 

[Gamingphreek]

Actually the first revision A had to do with the cache. Before the revision A the Williamettes were horribly slow because they could not do asynchronous cacheing. That is what the A denoted.

-Kevin