2x1GB recognized as 2x512MB RAM

[akadmon]

After getting a few beach-balls today, I checked the Activity Monitor and was shocked to see that it was only reporting 3GB RAM instead of 4GB (I have 2x1GB Techworks RAM and 2x2x512MB Apple OEM RAM). I next checked he System Profiler and it was showing that I have six 512MB sticks in there, and that all the RAM is OK. I ran TechTool and it did not find anything wrong with the RAM. I removed the Apple RAM and reseated the two 1GB sticks several times, but they're still being recognized as 512MB.

Anybody have any idea what could be going on? If the RAM is bad, would it not simply fail to be recognized altogether?

 

[Spanky Deluxe]

I'm no expert in such matters but I think I once heard that server (ECC) ram can run as a lesser size if it detects some of it being faulty. I may be barking up the wrong tree though. It does sound like you're going to have to dig out that warranty though.

 

[JayHM]

Did you ever figure this out? I'm experiencing the exact same thing. I installed four 1 gig sticks from transintl.com, and the two on the bottom riser are showing up correctly as 1 gig, but the two on the top riser show up as 512 meg each.

 

[leekohler]

Whoa! I have no answers, but let me know when you get some. That is disturbing.

 

[akadmon]

Did you ever figure this out? I'm experiencing the exact same thing. I installed four 1 gig sticks from transintl.com, and the two on the bottom riser are showing up correctly as 1 gig, but the two on the top riser show up as 512 meg each.

No answer. I called OWC and the tech immediately told me to send the RAM back for replacement. Unfortunately, I'm 1 day over the 30-day window for advance shipment, so I'll have to make do with only 2 GBs for a while.

 

[spork183]

No answer. I called OWC and the tech immediately told me to send the RAM back for replacement. Unfortunately, I'm 1 day over the 30-day window for advance shipment, so I'll have to make do with only 2 GBs for a while.

I'm asssuming it makes no difference, top or bottom riser?

 

[JayHM]

I think in my case, it ended up being just bad RAM. When I opened the case, I noticed the little red LED for DIMM 3 was lit (even though it showed up with status "OK" in System Profiler). DIMM 3 was one of the two that showed up with the incorrect size, so I'm sending both back.

 

[akadmon]

I'm asssuming it makes no difference, top or bottom riser?

Same thing no matter where.

 

[akadmon]

I think in my case, it ended up being just bad RAM. When I opened the case, I noticed the little red LED for DIMM 3 was lit (even though it showed up with status "OK" in System Profiler). DIMM 3 was one of the two that showed up with the incorrect size, so I'm sending both back.

I just took off the side panel with the computer running and sure enough a red LED on riser B is on (I moved the two 1GB sticks to riser B last time).

It sucks that the System Profiler, rember and Techtool are incapable of detecting this failure.

 

[72930]

If possible, try putting them in another mac, to see if it spots a problem

 

[dethl]

I have a pair of 512s that read as 256s

Your RAM is most likely bad if its reading as a lesser amount. I have a couple of 512s in my PM G5 that read is 256s. Tried testing them in my GFs dell and it refused to start up - always locked up at the memory test. Unfortunately I have no clue who made the RAM so I'm having to wait and save up money to replace the poor sticks.

OTOH - with it reduced I really haven't seen much performance loss, aside from having less ram. Only problem I have is WoW freezing if I leave it on the login screen but I think thats more of a software issue than anything else.