ECS 755 A2 RAM Issue

[sirfartalot]

I am running the above MB with a Sempron 3000+ and have updated the BIOS to ver 1.1b.

When I try to install a PC2700 DIMM in each slot, the system will not POST and I receive an intermittent tone from the PC Speaker.

When I try a single DIMM then either module will work in either socket so both modules and both sockets appear to be working BUT, they will only show the memory of either module as 256MB when they are both 512MB. I have checked with CPU-Z and this also shows that the modules are 256MB but if I put them in another board then they are correctly displayed as 256MB.

I've never come across anything like this before and any help would be greatly appreciated.

 

[Peter]

Early BIOSes for this board didn't support the Sempron yet, and one of the outcomes is incorrect RAM size detection.

When you're on the current BIOS already, chances are that your DIMMs aren't quite good enough for an AMD64 system. This often happens with material that doesn't live up to its SPD-declared speed grade. Try lowering the RAM speed limit in BIOS setup (to 133 or even 100 MHz) before you add the 2nd DIMM.

 

[sirfartalot]

It appears that it was the RAM. Whilst I used this RAM previously in another machine without any problems, it seems it wasn't up to the job here. I tried three different versions of the BIOS but it still wouldn't register the memory correctly.

Both were identical Micron Technology sticks according to CPU-Z but they are about a year or so old.

I swapped a single 1Gb module of PC2700 (which is only about a month old) out of another PC into this one and it was working fine. Everything (POST, Windows, CPU-Z etc) reported 1GB present.

Both the old and new RAM look to have fairly similar specs except the old RAM reports a module size of 256MB and the new RAM reports 4MB.

I had 1GB of PC2700 in either machine anyway so it hasn't really made any difference.