Installing 3 DDR2 sticks - which of the 4 slots to populate?

Solution 1:

The answer is YES

BUT

Do not install non even number of ram.

This will cause ALL your ram to run at half speed / single channel.

Insert them in pairs..

If you really want to do then you can put it in any available slot. Does not matter, and you can mix and match makes- because it is fairly generic ram, with generic timing and speeds.

Using 3 stick might cause your boot screen to beep, or moan that the ram is running half duplex, is uneven or might even show 400mhz instead 800mhz. That is normal. When you get another stick, it will get back to normal, but make sure they are all 800mhz

If you are putting in specific ram with boosted performance. then all 4 need to be the same so you can get the best performance.

Solution 2:

Quick Answer:

For the Asus M4A87D-M PRO motherboard put the Apacer 2GB PC-6400 CL5 800Mhz sticks in DIMM-A1 and DIMM-B1 and put the Transcend JetRAM 2GB PC2-6400 CL6 800Mhz in DIMM-A2

Detailed Answer:

Typically your motherboard manual will indicate some order in which to populate the DIMM slots. Motherboards which support Dual-channel architecture can run two or more DDR type memory modules in dual-channel configuration. Theoretically, dual-channel configurations double the memory bandwidth when compared to single-channel configurations though it would seem that this may result in little to no real world performance increases (see this article)

DIMM Socket Color Codes:

Motherboards supporting dual-channel memory layouts typically have color-coded DIMM sockets. Coloring schemes are not standardized and have opposing meanings, depending on the motherboard manufacturer's intentions and actual motherboard design.

Matching colored DIMM sockets may indicate one of two possibilities depending on the motherboard:

• Matching colored sockets belong to the same channel and indicate that DIMM pairs should be installed to differently colored sockets

• Matching colored sockets belong to different channels and indicate that DIMM pairs should be installed to the same color.

Guidelines for dissimilar memory modules:

1. Modules rated at different speeds can be run in dual-channel mode, although the motherboard will then run all memory modules at the speed of the slowest module.

2. Some motherboards, may have compatibility issues with certain brands or models of memory when attempting to use them in dual-channel mode. For this reason, it is generally advised to use identical pairs of memory modules (matching capacity (eg: 1024MB), Speed (eg: PC5300), CAS Latency, Number of chips and sides, etc.)

3. For maximum performance, populate the sockets so that the memory capacity is spread as equally as possible between two Channels. A matched pair of memory modules may usually be placed in the first bank of each channel, and a different-capacity pair of modules in the second bank. eg: 2x 2GB DIMMS in Channel A and 2x 1GB DIMMS in Channel B.

4. For systems with only 1 DIMM socket you have no option (runs in Single Channel mode)

5. For systems with 2 DIMM sockets place the largest memory capacity DIMM into the first DIMM socket i.e. Channel A, Bank 1 and the second in Channel B, Bank 1.

6. For systems with 3 DIMM sockets place the largest memory capacity DIMM into Channel A, Bank 1, place the second largest memory capacity DIMM in Channel B, Bank 1 and the third DIMM in Channel A, Bank 2. Preferably largest capacity DIMM should equal sum of smaller capacity DIMMs (eg: 1GB = 512MB + 512MB)

7. For systems with 4 DIMM sockets place the largest memory capacity DIMM into Channel A, Bank 1, place the second largest memory capacity DIMM in Channel B, Bank 1, the third largest memory capacity DIMM in Channel A, Bank 2 and the fourth in Channel B, Bank 2.

References:

1. Asus M4A87D-M PRO motherboard manual page

2. Tom's Hardware - "Parallel Processing, Part 2: RAM and HDD"

3. Multi-channel memory architecture

4. HP Support

5. Lenovo Support