AMD Phenom II X2 B55 vs AMD Phenom X3 8400

Table of Contents

Physical Specifications

Socket AMD Socket AM3 AMD Socket AM2+
Process size 45 nm 65 nm
Transistors 758 million 450 million
Die size 258 mm² 285 mm²
Package µPGA µPGA


Frequency 3 GHz 2.1 GHz
Turbo clock
Base clock 200 MHz 200 MHz
Multiplier 15.0x 10.5x
Multiplier unlocked No No
Voltage 1.425 V 1.25 V
TDP 80 W 95 W

Architecture Details

Vertical Segment Desktop Desktop
Production status End-of-life End-of-life
Release date Oct 1st, 2009 Mar 27th, 2008
Codename Callisto Toliman
Generation Phenom II X2 Phenom X3
Memory support DDR3 Dual-channel unknown Dual-channel
ECC memory No No
PCI Express Gen 2 Gen 2


Total Cores 2 3
Total Threads 2 3
SMP # CPUs 1 1
Integrated graphics


Cache L1 128K (per core) 128K (per core)
Cache L2 512K (per core) 512K (per core)
Cache L3 6MB (shared) 2MB (shared)


Notes AMD Business Class processor, availability guaranteed for 24 months after release. Processor with the older B2 revision and TLB Bug.

Features & Technologies

3DNow! Yes Yes
AMD-V Yes Yes
AMD64 Yes Yes
CnQ Yes
HT3.0 Yes
MMX Yes Yes
NX bit Yes Yes
SSE Yes Yes
SSE2 Yes Yes
SSE3 Yes Yes
SSE4A Yes Yes


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