Asus P4P8X: 1.9 System memory

1.9 System memory

The motherboard comes with four Double Data Rate (DDR) Dual Inline Memory

Module (DIMM) sockets. These sockets support up to 4GB system memory using

184-pin unbuffered non-ECC PCPC2700/PC2100 DDR DIMMs. The following

figure shows the location of the DDR DIMM sockets.

P4P8X

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Chapter 1: Product introduction

DIMM_A

80 Pins104 Pins

P4P8X 184-Pin DDR DIMM Sockets

DIMM_A

DIMM_B

DIMM_B

1.9.1 Memory configurations

You may install 64MB, 128MB, 256MB, 512MB, and 1GB DDR DIMMs into the

DIMM sockets using the memory configurations in this section.

Important notes

1. Installing DDR DIMMs other than the recommended configurations may

cause memory sizing error or system boot failure. Use any of the

recommended configurations in Table 1.

2. In dual-channel configurations, install only identical (the same type and

size) DDR DIMM pairs for each channel.

3. Always install DIMMs with the same CAS latency. For optimum

compatibility, it is recommended that you obtain memory modules from the

same vendor.

4. Make sure that the memory frequency matches the CPU FSB (Front Side

Bus). Refer to Table 2.

5. DIMMs installed into any three sockets will function in single-channel

mode.

6. When all four sockets are populated with 1GB DIMMs (total 4GB), the

system may detect only 3+GB (a little less than 4GB) due to ICH5 resource

allocation.

7. Double-sided DDR DIMMs with x16 (databus width = 16-bit) memory chips

are not supported due to chipset limitation.

8. It is recommended to use the blue DIMM slots first.

Table 1 Recommended memory configurations

Sockets

Mode DIMM_A1 DIMM_A2 DIMM_B1 DIMM_B2

(blue) (black) (blue) (black)

Single-channel (1) Populated — — —

(2) — Populated — —

(3) — — Populated —

(4) — — — Populated

Dual-channel (1) Populated

— Populated —

(2) —

Populated — Populated

(3)* Populated Populated Populated Populated

* For dual-channel configuration (3), you may:

• install identical DIMMs in all four sockets, or

• install identical DIMMs in DIMM_A1 and DIMM_B1 (blue sockets)

and identical DIMMs in DIMM_A2 and DIMM_B2 (black sockets)

Table 2 Memory frequency/CPU FSB synchronization

This motherboard supports different memory frequencies depending on the CPU

FSB (Front Side Bus) and the type of DDR DIMM.

CPU FSB DDR DIMM Type Memory Frequency

800 MHz PC3200 400 MHz

533 MHz PC2700/PC2100 333/266 MHz

400 MHz PC2100 266 MHz

• When overclocking to 800MHz CPU FSB, the system supports only

DDR400 (PC3200) DIMMs due to chipset limitation.

• The following FSB/DDR ratios are not supported: 400/333, 400/400,

533/400.

ASUS P4P8X motherboard user guide

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