I just recently bought 1gb of pc4200 DDR2 ram from the egg. I have a ECS P4M800Pro-M v1.0A. I removed the old DDR ram because you can't use DDR and DDR2 at the same time and just put in the new 1gb stick. I booted and on the black boot up screen it detected only 512mb of DDR2. It went into windows xp with no other problems though. I went into the system properties and it also only detects 512mb of ram. I then ran CPUZ and PC WIZARD 2008 and those programs detected the full stick. I can still do everything i did before but i was hoping for some performance increases with 1gb. My problem is that only half of the ram is detected. Does anyone know how to fix this problem? I have updated the bios once but the latest update from ECS would no update. I have also tried the other slot but i get the same result.
ECS P4M800Pro-M v1.0A mobo
Kingston ValueRAM 1GB 240-Pin DDR2 SDRAM DDR2 533 (PC2 4200)
I have the same motherboard (well, v2.0 but it's the same pretty much). The problem is that the ram you have received is of a higher density that is not supported by the motherboard. If you look at your ram module you'll see it is single-sided, where there are 8 chips on one side and none on the other. The module is 1 rank of 1GB, however the motherboard can only read up to 512MB from a single rank (hence why only 512MB is recognized). Your ram is at the density 128Mx8 or higher.
What you need is a lower density ram, which is quite hard to find these days... back when the P4M800PRO-M was first being manufactured this type of ram was more common. Look for ram that is 64Mx8. This will be double-sided ram, where there are 8 chips on each side of the module.. making a total of 16 chips. This is because there are two ranks, a rank of 512MB on one side and another rank of 512MB on the other side.. making together 1GB that is fully recognized by the motherboard.
I have two of those and it's working fine, as you can see its 64Mx8 with 16 chips.. speed is the maximum that the motherboard supports. There are some others I found but they are mostly generic and/or very low quality.