Specifications

Chapter 2. Architecture and technical overview 51
2.2.3 Processor comparison
The 2-socket and 4-socket processor cards available for the Power 780 utilize slightly different
POWER7 processors. Table 2-6 shows a comparison.
Table 2-6 Comparison of processors used with 2-socket and 4-socket processor cards
The most significant difference between the processors are the interconnects. On the
2-socket processor card, the POWER7 processor has two memory controllers, each
connected to four memory DIMMs (Figure 2-10).
Figure 2-10 Processor interconnects on 2-socket processor card
Area POWER7 processor used on
2-socket CPU card
POWER7 processor used on
4-socket CPU card
Technology 45 nm 45 nm
Die size 567 mm
2
567 mm
2
Power 250 W 150 W
Cores 8 6
Max frequency 3.92 GHz
(4.14 GHz with TurboCore)
3.44 GHz
L2/L3 256 K/4 MB per core 256 K/4 MB per core
Memory support DDR3 DDR3
Fabric Bus Star Fabric Bus Star Fabric Bus
I/O Bus Two GX++ Two GX++
TurboCore mode Yes No
Sleep/nap mode Yes Yes
P7
XYZ
A
B
MC0
MC1
GX1
GX0
DIMM 1
DIMM 2
DIMM 3
DIMM 4
DIMM 1
DIMM 2
DIMM 3
DIMM 4
GX1 Bus (4 Byte – 2.46Gb/s)
GX0 Bus (4 Byte – 2.46Gb/s)
Z Y X Buses
8 byte
3.248 Gb/s
A B Buses
8 byte
2.464 Gb/s