Build A PC

A custom PC configuration guide. © 2000,2001,2002 by Jef Poskanzer.


Here's a table showing the most important aspects of the various CPUs.

connector L2 cache speed FSB speed memory speed
Pentium 4 Xeon mPGA-603 CPU 400MHz DDR / RDRAM
Pentium 4 Socket-478 CPU 400/533MHz DDR / RDRAM
Athlon C/XP/MP Socket-A CPU 266/333MHz 133MHz / DDR
Pentium 4 Socket-423 CPU 400MHz 133MHz / RDRAM
Pentium III Tualatin FC-PGA2 CPU 133MHz 133MHz
Duron, Athlon B Socket-A CPU 200MHz 133MHz
Cyrix/VIA M-III Socket-370 CPU 133MHz 133MHz
Athlon A Slot-A variable, <1/2 CPU 200MHz 133MHz
Celeron II FC-PGA CPU 66MHz 66MHz
Pentium III EB Slot-1, FC-PGA CPU 133MHz 133MHz
Pentium III Xeon Slot-2 CPU 100MHz 100MHz
Pentium III Slot-1 1/2 CPU 100MHz 100MHz
K6-III super-7 CPU 100MHz 100MHz
K6-2 super-7 FSB 100MHz 100MHz
Celeron A Socket-370 CPU 66MHz 66MHz
Pentium II Socket-7 1/2 CPU 66MHz 66MHz
Cyrix M-II Socket-7 FSB 66MHz 66MHz

L2 cache speed refers to how fast the level-2 cache runs. All modern CPUs have a multi-level memory cache structure. Level-1 cache always runs at the same speed as the CPU, but it's small. Level-2 cache is larger, but may run slower - half the CPU speed or less.

FSB means front side bus - the main highway between the CPU and the rest of the system. The memory, PCI bus, AGP bus, all hook into the FSB. It runs at the same speed as the memory, except in the Athlon/Duron where it runs at 200MHz, and in the Pentium 4 where it runs at 400MHz.

And if that's not enough, here are some amazingly detailed tables from Tom's Hardware that show even more.

Some other notes:

OEM vs. Retail Packaging

When shopping for CPUs you may find you can buy either the OEM package or the retail package, and the OEM package is cheaper. So which should you get? The difference is that the retail package includes a heat sink and fan, while the OEM package does not. If you are going to buy a hopped-up aftermarket heat sink and fan, then of course you want the OEM package. If you don't care too much about the heat sink and fan, you might as well buy the retail package.

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