I kinda got that much but I am looking for a more refined answer. Which specific P4 3.4GHz Prescot with a 1MB L2 cash? I found more than one model number for that discription. I made that mistake when buying my I7 920, I went for the vague discription and now I got a CO, I latter learned that not only do one want DO but they should make sure if they can get a their 1366 I7 920 from specific batches as they overclock better. These P4s have been out for quite some time and so should be more understood.
I see what you are asking. I have done the same. I run a prescott 3.4e with d0 stepping. If I am not mistaken there is an even later version that dropped volts, because of the 130w+ twd (very hot). The d0 is as new as it gets for the fastest one, the volt droppers aren't...and it is a hot one. can't stand the heat..go get the later revision.
The 478 socket processors are mostly Pentium 4 processors, however there are also some Pentium 4 Extreme Processors which are for 478 socket.
From this link I think the fastest socket 478 processor will be the Pentium 4 Extreme Edition Processor
Moreover, each model of processors will be have a specific unique number. If you want to determine which processor you have you just need to find the SL number and find the details of that processor on the processor Specfinder . The SL number will be found either on the box of the processor or on the processor metal surface. There is no other way to determine the exact stepping of the processor without using the SL number. Eg of SL number is SL7CH.
Hope this will be useful to you.
I think I found my answer, it seems that the fastest 478 was a P4 Extreem 3.4GHz with 2MB L3 Cache, MO stepping, 0.13 micron. BX80532PG3400F - RK80532PG0962M (SL7CH). It's far to rare and would cost more than an X58 975. After that there are a few listed below of which I cannot tell which is better. A few have different stepping but the same box number, confusing
sSpec# CPU Speed Processor # Cores Bus Speed Mfg Tech Stepping Cache Size Package PCG/FMB SL7KD 3.40 GHz N/A 1 800 MHz 90 nm E0 1 MB 478 pin N/A SL7PP 3.40 GHz N/A 1 800 MHz 90 nm E0 1 MB 478 pin N/A SL7E6 3.40 GHz N/A 1 800 MHz 90 nm D0 1 MB 478 pin N/A SL7AJ 3.40E GHz N/A 1 800 MHz 90 nm C0 1 MB 478 pin N/A SL7B9 3.40 GHz N/A 1 800 MHz 90 nm C0 1 MB 478 pin N/A SL8K4 3.40 GHz N/A 1 800 MHz 90 nm G1 1 MB 478 pin N/A SL88L 3.40 GHz N/A 1 800 MHz 90 nm E0 1 MB 478 pin N/A
SL7KD Box# BX80546PG400E OEM# B80546PG0961M Stepping EO
SLPP Box# OEM# RK80546PG0961M Stepping EO
SL7E6 Box# BX80546PG3400E OEM# RK80546PG0961M Stepping DO
SL7AJ Box# BX80546PG3400E OEM# Stepping CO
SL7B9 Box# BX80546PG3400E OEM# Stepping CO
SL8K4 Box# BX80546PG3400E OEM# NE80546PG0961M Stepping G1
SL88L Box# BX80546PG3400E OEM# B80546PG0961M Stepping EO
Actually from the list you have provided, they are all almost the same. Some with different revisions/stepping.
If a processor have a different stepping, for example, E0 and M0, it does not mean that the M0 is better than the E0 stepping.
Processors have different stepping, based on their manufacturing, or any changes made during the manufacturing process.
Concering the different box number, this is generally for administration use, especially they will have more meaning for resellers and distributors.
Point to note is that any processor which is boxed is available to the consumers. However those who are classified as tray or OEM are only available to system manufacturers and OEMs. Tray processors do not have any warranty. Warranty is provided by the OEM themselves.
Hope this is helpful to you.