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netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
415
NH
So, I recently bought a Mac Pro (2.66GHz, 1GB RAM).

I just ordered another 2 GB RAM from OWC. It arrived today and I installed in Riser B, Slots 1/2.

I was doing some iPhoto imports and opened System Profiler to find 1 stick of the OWC RAM had 4 ECC Errors.

So, I went ahead and moved the 2 Apple 512 sticks to the lower riser, and moved the OWC 1GB sticks to the upper riser.

I downloaded Rember and ran that using as much memory as possible. I got another 1 ECC Error this time on each of the OWC memory. I then ran another import in iPhoto and got a total of 3 more ECC Errors.

Obviously I'm calling OWC tomorrow and getting an RMA, but now I'm in a situation where:

a) Do I assume the OWC memory was a bad batch? and get more?
b) Do I go to some other 3rd party?
c) Do I only get 1 GB total of Apple RAM?

At no point during these tests, or since having the Mac Pro has the Apple memory reported any errors.

Let me add that at no point during this testing, did my system seem to have problems. No kernel panics, or software errors. The other errors were listed in the System Profiler.

Can anyone advise on what they think I should do?

Apple's 2GB upgrade is $700 bucks....that seems crazy to me, but if the RAM works, then I guess I have no choice.

-Kevin
 

CanadaRAM

macrumors G5
These didn't result in crashes, did they? They are listed as correctable ECC errors? Up to a certain point, that's exactly what ECC RAM is supposed to do - correct the random single-bit errors that would normally crash normal RAM or introduce corruption into data.

Apple's standard for Correctible ECC errors is 4 correctable errors in 48 hours.

Get the replacement OWCs and try again -- there's little or no downside to doing that. If it is persistent, the RAM may be bad, or you may have a problem with the memory risers themselves, or your installation technique -- just some possibilities.
 

netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
415
NH
These didn't result in crashes, did they? They are listed as correctable ECC errors? Up to a certain point, that's exactly what ECC RAM is supposed to do - correct the random single-bit errors that would normally crash normal RAM or introduce corruption into data.

Apple's standard for Correctible ECC errors is 4 correctable errors in 48 hours.

Get the replacement OWCs and try again -- there's little or no downside to doing that. If it is persistent, the RAM may be bad, or you may have a problem with the memory risers themselves, or your installation technique -- just some possibilities.

No crashes.
Yes they were listed as correctable.

I read that Apple states 4 correctable errors in 48 hours. I guess my main problem is that I did a simple import in iPhoto of about 1000 images, and got 4 errors.

I made sure all the RAM was seated correctly and the risers were seated correctly. That's also why I switched the RAM between risers to test whether Riser B was bad. Obviously it's not the riser as the errors followed the RAM.

-Kevin
 

netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
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NH
Update 3/29:

OWC Customer Service was extremely nice and helpful! They are sending me out new sticks and I'll be able to try them tomorrow.

I'll report back here the results.

-Kevin
 

TheFuzz

macrumors regular
Aug 18, 2006
147
0
LA
i had a similiar problem with ram ordered from owc. i added 4x1GB to the 4x512MB i ordered w/ the machine from apple. the owc sticks seemed fine until i started rendering out of cinema 4d. during a 51 hour render all sticks had 1 correctable error except for one, which had two errors. i ran rember and it didn't find any problems. owc was ready to send me new sticks but i wanted to be sure that it was the ram and not some other factor that would cause the same problems with the replacement sticks. i reseated them all and tried rendering the same scene again, this time monitoring the temps, which i found to be rising above 180F. i noticed that the fans would not increase with the increase in temps so i downloaded an app that allows you to adjust your fan speeds. now, during renders i just set the fans to run at higher speeds which keeps the temps way down, like around 130F-140F, and haven't had an error since.

btw- the owc ram has the large, black heatsinks(spreaders,?) like the apple ram
 

netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
415
NH
i had a similiar problem with ram ordered from owc. i added 4x1GB to the 4x512MB i ordered w/ the machine from apple. the owc sticks seemed fine until i started rendering out of cinema 4d. during a 51 hour render all sticks had 1 correctable error except for one, which had two errors. i ran rember and it didn't find any problems. owc was ready to send me new sticks but i wanted to be sure that it was the ram and not some other factor that would cause the same problems with the replacement sticks. i reseated them all and tried rendering the same scene again, this time monitoring the temps, which i found to be rising above 180F. i noticed that the fans would not increase with the increase in temps so i downloaded an app that allows you to adjust your fan speeds. now, during renders i just set the fans to run at higher speeds which keeps the temps way down, like around 130F-140F, and haven't had an error since.

btw- the owc ram has the large, black heatsinks(spreaders,?) like the apple ram

Well, I don't think it's a heat related issue....in that the tests I was doing were relatively short in duration. Only importing 1000-2000 photos....so it only took a couple minutes. And the test was run after I swapped RAM from one riser to the other....so the machine was cool.

Not sure exactly how hot the RAM can get in that short period of time.

What's the program for testing the fans and adjusting? Do you think it's a problem with your machine in that it didn't ramp up the fan speed?

-Kevin
 

TheFuzz

macrumors regular
Aug 18, 2006
147
0
LA
there's an old thread discussing the mac pro and its fan speeds and i remember others saying they experienced the same thing w/ their mac pros. i can only assume it's apple wanting to keep them quiet... i guess.
 

piltupso

macrumors regular
Apr 29, 2006
123
0
I am in the market for some RAM myself and would be interested to hear how your story ends. Also if anyone knows what is the difference on the Netlist certified RAM and the Apple certified RAM on OWC's site? I would also be interested to know which heat sinks they show up with as near as I can find out on the site there are a couple they could show up with.
 

CanadaRAM

macrumors G5
during a 51 hour render all sticks had 1 correctable error except for one, which had two errors.

According to Apple, this is well within spec. (4 correctible in 48 hours)

Rendering is about the hardest you can work the RAM. If you want to test RAM, it is a better workout than Rember or TechTool Pro.

Reducing heat is always a good way to reduce error -- despite popular misconception, it is not the design of the heatsink that is the issue but the ability of the MacPro to move air through to transport the heat outside the case. Apple wanted the machine to be quiet, so IMO they went too low on fan speeds. Given a deficiency in the removal of heat from the case, a large heatsink just delays the point at which the RAM overheats.

Keep in mind that these very same FB-DIMM modules work fine WITHOUT large heatsinks in rackmount Xeon servers including slimline 1U rackmounts -- of course the server manufacturers aren't concerned about noise, and they just blast the cooling air through.
 

netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
415
NH
Reducing heat is always a good way to reduce error -- despite popular misconception, it is not the design of the heatsink that is the issue but the ability of the MacPro to move air through to transport the heat outside the case. Apple wanted the machine to be quiet, so IMO they went too low on fan speeds. Given a deficiency in the removal of heat from the case, a large heatsink just delays the point at which the RAM overheats.

Keep in mind that these very same FB-DIMM modules work fine WITHOUT large heatsinks in rackmount Xeon servers including slimline 1U rackmounts -- of course the server manufacturers aren't concerned about noise, and they just blast the cooling air through.

I agree....seems like Apple set the temp thresholds way too high for the Mac Pro. I can get RAM up to 185F and CPU up to 150F and the Mac Pro never kicks up the fans. I can do it manually, but it's not really something I want to baby sit.

As for my new memory from OWC.....I probably will be returning it. It tends to run a little hot, even at idle speeds. And I am getting ECC errors on Rember....but I'm starting to think it's due to heat. Unless I get more data from other people with their memory temps, it'll probably be going back and I'll try Crucial.

-Kevin
 

netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
415
NH
I am in the market for some RAM myself and would be interested to hear how your story ends. Also if anyone knows what is the difference on the Netlist certified RAM and the Apple certified RAM on OWC's site? I would also be interested to know which heat sinks they show up with as near as I can find out on the site there are a couple they could show up with.

Couldn't tell you because I ordered the OWC RAM, but they sent (both times) the Netlist. I've seen other reports of people also getting the Netlist.

I can't say enough about OWC's Customer Service. They have been extremely helpful and friendly.

I'm not real happy with the temps on the OWC RAM, so they might be going back. Don't think it entirely OWC's fault. I'm placing some blame on Apple and the fact that the fans don't increase at all for me....I have to do it manually.

I'll keep updating this thread with my progress....might try Crucial next.

-Kevin
 

netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
415
NH
UPDATE: 4/5/07

I've been running with the 2x1GB Crucial Ram for a couple days now. Absolutely no problems thus far. This RAM has almost the identical heatsinks as the Apple RAM.

I've run iPhoto imports (this is what started the OWC with ECC errors) and Rember. So far no ECC Errors with the Crucial

My temps are higher with the Crucial over the Apple, but I'm chalking that up to the fact they are 1 GB DIMMS and they'll generate more heat.

I still can't say enough about OWC's customer service. They have been great in the replacements and allowing me to return the RAM. Very friendly staff over there.

More than anything I'm realizing my problem was likely due to heat and the Mac Pro not ramping up the fans. Seems maybe the Crucial RAM can handle the higher temps a little better.....at least in my case.

-Kevin
 

netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
415
NH
So to update everyone on my RAM issues.

1) First set from OWC...returned because of ECC Errors and no kernel panics
2) Second set from OWC returned because of ECC Errors and 1 kernel panic
3) First set from Crucial returned because of multiple kernel panics
4) Second set from Crucial working good so far.

I am noticing that all previous RAM before this last set, ran much hotter than the Apple DIMMS. This new set from Crucial run almost identical in heat to Apple's 512 DIMMS (these are 2x1GB from Crucial). Not sure whether the heatsinks are working better, or they put thermal paste on them....who knows.

So far no errors or kernel panics (knock on wood).

-Kevin
 

netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
415
NH
Thanks, I like smcFanControl. :)

Me too. Shame Apple makes us get this utils. It would be nice to be able to adjust the Apple-set temps to kick the fans on, then I wouldn't have to do it manually.

-Kevin
 

netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
415
NH
Any updates? I hope all is well.

The 2nd set from Crucial has been working great. No Kernel panics or problems. The 1 GB DIMMS from Crucial actually run at or below the 512 MB DIMMS from Apple as far as temperature.

-Kevin
 

tuartboy

macrumors 6502a
May 10, 2005
747
19
I actually have had a decent amount of problems with my OWC ram too. Out of 4 x1GB sticks, I replaced 1 set due to nearly instant KPs, and there are 2 currently reporting errors. One is within the 4 in 48 hours limit, but the other does 100 or so a day. No crashes and everything is stable, but I will likely send back these 2 when I am not so busy. I run aperture and CS3 all day nearly every day and 5GB is hardly enough! Right now I can't stand going back to 3GB while I wait for replacements.

Best of luck with your ram.
 

miniConvert

macrumors 68040
Just a quick 'yay' for smcFanControl!

I raised my minimums from 500rpm to 700rpm and I honestly don't notice a difference in noise. I do, however, have the benefit of a slightly cooler system. Where are the number of ECC errors displayed? If it's just through System Profiler then I've never seen a single one, though I do use Apple RAM.

After some of the wind tunnel PowerMac G5 stories I can completely understand why it was so important that Apple made the Mac Pro so quiet. They just probably went a touch too far.
 

dk99

macrumors newbie
May 27, 2007
5
0
i was already going to buy OWC RAM

The 2nd set from Crucial has been working great. No Kernel panics or problems. The 1 GB DIMMS from Crucial actually run at or below the 512 MB DIMMS from Apple as far as temperature.

-Kevin

Does that really mean that this RAM from OWC does not work reliabally in the Mac Pro? I just ordered an Octo 2 days ago and hesitate now, where to buy the RAM. Will be glad for any suggestions. Thanks!
I also wonder: Do You see this EEC errors in the system profiler?
 

netnothing

macrumors 68040
Original poster
Mar 13, 2007
3,806
415
NH
Does that really mean that this RAM from OWC does not work reliabally in the Mac Pro? I just ordered an Octo 2 days ago and hesitate now, where to buy the RAM. Will be glad for any suggestions. Thanks!
I also wonder: Do You see this EEC errors in the system profiler?

I think it's unique to each system, and the environment that it's in. I had no luck with the OWC RAM, but others have. My first set from Crucial was no better. It wasn't until the second set from Crucial, that I got a pair of DIMMS that seem to be working under all conditions.

Yes, the ECC errors were reported in the System Profiler.

I personally wanted the Crucial because the heatsinks were almost identical to the stock Apple RAM. I know other vendors have similar heatsinks, but I just ended up going with Crucial.

Just make sure wherever you buy RAM from, that they have an excellent return policy. Both OWC and Cruicial have been great in the customer service dept....both allowing the exchanges/returns, no questions asked.

-Kevin
 

macenforcer

macrumors 65816
Jun 9, 2004
1,248
0
Colorado
I got my mac pro the day they came out literally. Nobody had ram then. I got some ram from crucial without the heatsinks and I put heatsinks on them but I got constant ecc errors. I sent them back and ordered 2 x 2gb kingstons from newegg and took the apple heat spreaders off the 512mb dimms and put them on the 2gb ones. I slapped a bunch of heatsinks on the apple 512mb dimms and I have been running smoooooth ever since. Not a single ecc error ever.

ECC errors are bad. They mean there is a problem. The fact that the ram corrects them errors is irrelevant.
 
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