Service manual

C-6 Sun Ultra 2 Series Service Manual • July 1996
Characteristic memory performance includes a peak memory read bandwidth of 667
Mbytes per second and a peak memory write bandwidth of 485 Mbytes per second
with random accesses to the DRAM using eight or more DSIMMs. The following
figure shows the DSIMM group and bank layout.
Note – Two pairs of DIMMs form a group of four DIMMs. All four DIMMs within a
group must be the same size. The minimum memory requirement is four DIMMs in
Group 0. DIMMs can be installed in Group 1, Group 2, or Group 3 in any order. Each
group addresses 512 Mbytes of memory. Unused memory is mapped out by the
memory management hardware.
FIGURE C-2 DSIMM Group and Bank Layout
CPU 0 J2801
CPU 1 J2901
Group 3
U0403
U0503
U0603
U0703
U0404
U0504
U0604
U0704
U0401
U0501
U0601
U0701
U0402
U0502
U0602
U0702
Group 2
Group 1
Group 0
System Front
Bank 1
Bank 1
Bank 1
Bank 1
Bank 0
Bank 0
Bank 0
Bank 0
Pair 7
Pair 7
Pair 6
Pair 6
Pair 5
Pair 5
Pair 4
Pair 4
Pair 3
Pair 3
Pair 2
Pair 2
Pair 1
Pair 1
Pair 0
Pair 0