memory errors

[rtrt]

a

 

[darkpaw]

in case it's relevant have the mem installed this way;

Dimm riser A/Dimm 1 - 1G
Dimm riser A/Dimm 2 - 1G
Dimm riser A/Dimm 3 - 2G
Dimm riser A/Dimm 4 - 2G
Dimm riser B/Dimm 1 - 2G
Dimm riser B/Dimm 2 - 2G
Dimm riser B/Dimm 3 - empty
Dimm riser B/Dimm 4 - empty

That's the way mine is installed. I followed the directions from OWC's install sheet included with the RAM.

Have you run the Apple Hardware Tests CD?

You could also try removing and re-seating the RAM.

 

[yeroen]

On Riser A, put the 2 GB modules in the front slots (1 and 2) and move the 1GB ones to the rear, and see if that improves things.

For performance reasons alone, you always want to put your highest-capacity RAM up front, otherwise you incur a small latency cost when the smaller modules up front "fill up" and have to mediate access to the rear modules.

But also for reliability. For some occult reason, I've found that running with smaller modules in front always seems to generate more ECC errors. When I first ran my Netlist 1GB modules behind Apple 512MB ones, I'd get cascading ECC errors that disappeared once I put the higher capacity RAM up front.

 

[subaqua]

On Riser A, put the 2 GB modules in the front slots (1 and 2) and move the 1GB ones to the rear, and see if that improves things.

For performance reasons alone, you always want to put your highest-capacity RAM up front, otherwise you incur a small latency cost when the smaller modules up front "fill up" and have to mediate access to the rear modules.

But also for reliability. For some occult reason, I've found that running with smaller modules in front always seems to generate more ECC errors. When I first ran my Netlist 1GB modules behind Apple 512MB ones, I'd get cascading ECC errors that disappeared once I put the higher capacity RAM up front.

For what it's worth. I'd recommend getting iStat (http://islayer.com) and monitor the temperatures of each FB-DIMM. I manually increased the CPU and Chassis Fan speeds to keep the temperatures below 155 F. This resulted in no more ECC errors for me. Your milage may vary ...

Also, you may find that the FB-DIMM generating the ECC errors is running unusually hot.

 

[yeroen]

After you put the larger RAM in front , install smcFanControl:

http://homepage.mac.com/holtmann/eidac/software/smcfancontrol2/index.html

and bump up the rear fans from their default 500 or 600 RPM. I run my rear fans at 1000RPM, at which speed the fan noise is just below my audible threshold.

And as the above poster recommended, you can install the iStatPro dashboard widget to monitor temps. You can also run TemperatureMonitor:
http://www.bresink.de/osx/TemperatureMonitor.html

 

[rtrt]

a

 

[rtrt]

a

 

[bilbo--baggins]

new 4 x 2G ram. looked on system profiler and see the following;

DIMM Riser A/DIMM 3:

Size: 2 GB
Type: DDR2 FB-DIMM
Speed: 800 MHz
Status: ECC Errors
ECC Correctable Errors: 14
Manufacturer: 0x05F7
Part Number: 0x000000003732353642363145353636374600
Serial Number: 0x00000000

Not been pushing the box at all. been promising myself to run some hardware tests but not got round to it yet. am thinking that i should def make sure i push the memory hard to see if any of the other dimms show a problem.

in case it's relevant have the mem installed this way;

Dimm riser A/Dimm 1 - 1G
Dimm riser A/Dimm 2 - 1G
Dimm riser A/Dimm 3 - 2G
Dimm riser A/Dimm 4 - 2G
Dimm riser B/Dimm 1 - 2G
Dimm riser B/Dimm 2 - 2G
Dimm riser B/Dimm 3 - empty
Dimm riser B/Dimm 4 - empty

interested in others thoughts

That configuration should be fine, I would recommend getting the RAM replaced and not trying to find a way of making it work. You have followed Apple's instructions precisely. Maybe just check that the modules are seated properly first.

 

[bigbird]

Maybe just check that the modules are seated properly first.

It's almost impossible to not seat MP RAM properly. If the tabs push up when you press the RAM in, that's the best you can do.