OK, this is a small run-down on my XP Pro system:
BIOS Award Software, Inc. ASUS A7V266-E ACPI BIOS Rev 1010 06/26/2002
System Board ASUSTeK Computer INC. A7V266-E REV 1.xx
Processor
Brand/Model AMD Athlon or Duron Model 6
Nominal Clock Speed 1544 MHz
Measured Clock Speed 1545 MHz
External Clock Speed 133 MHz
CPUID Information 0x0662 0x383F9FF
CPU Load 0%
Level 1 Cache 128 KB
Level 2 Cache 256 KB
Speed Rating 4047 MB/s
Memory Configuration
RAM installed 512 MB
Windows RAM 512 MB
Total RAM slots 3
Available RAM slots 1
Max RAM module size 512 MB
Memory Type 256+256+0;DIMM,DRAM,|Synchronous|;T16
Level 1 Cache 128 KB
Level 2 Cache 256 KB
Speed Rating 4047 MB/s
Where it refers to "External Clock Speed 133 MHz" is it refering to Front side bus?
If so this board is 266 and the processor is 266. Could the drop be due to using 2-256mb sticks of PC 2700 vs 1-512?
Not meaning to sound ignorant, this is one of those things that has always baffeled me.