User's and BIOS Manual (1.0)

5-8
AS1020P-T(R)/1020P-8(R) User's Manual
Figure 5-5. Side and Top Views of DDR Installation
To Install:
Insert module vertically
and press down until it
snaps into place. The
release tabs should
close - if they do not
you should close them
yourself.
Note the notch in the slot and on the bottom of the DIMM.
These prevent the DIMM from being installed incorrectly.
Support
The H8DSP-8/H8DSP-i supports single or dual-channel, registered ECC
DDR400/333/266/200 SDRAM.
Both interleaved and non-interleaved memory are supported, so you may populate
any number of DIMM slots (see note on previous page and charts on following
page). The CPU2 DIMM slots can only be accessed when two CPUs are installed
(however, the CPU2 DIMM slots are not required to be populated when two CPUs
are installed).
Populating two adjacent slots at a time with memory modules of the same size and
type will result in interleaved (128-bit) memory, which is faster than non-interleaved
(64-bit) memory.
Optimizing memory performance
If two processors are installed, it is better to stagger pairs of DIMMs across both
sets of CPU DIMM slots, e.g. fi rst populate CPU1 slots 1A and 1B, then CPU2 slots
1A, and 1B, then the next two CPU1 slots, etc. This balances the load over both
CPUs to optimize performance.
Maximum memory (two CPUs): 32 GB for DDR266/200 and 16 GB for
DDR400/333. If only one CPU is installed, maximum supported memory is halved
(16 GB for DDR266/200 and 8 GB for DDR400/333).
which requires modules of the same size and speed to be installed in pairs.
You should not mix modules of different sizes and/or speeds.
Memory Speed Jumpers
Depending on what type of memory you use, you may need to change the XJ4F1
and XJ4F2 (Memory Speed Select) jumpers. See pages 5-10, 5-11 and 5-20 for
details.