Unstable after RAM upgrade

I just got some ram from crucial and so far at 20 hours of uptime it's working great. I called apple support on this since this is the third set of memory I've tried and they said if the crucial set locks up too just exchange the macbook since you're within the two weeks exchange period (which ends today). I'm not calling a victory yet though since the last set from OWC took 40 hours before it started locking up.

My usage patterns are 70% browser/mail/light activity and 30% handbrake/unreal tournament 2004/high cpu. Always locked up under low usage, low temperature conditions. Memtest always passed.

Did yours just freeze without a kernel panic?

1 day 14 hours on the OWC RAM - no reboots or freezes, Handbrake, browsing, installing applications, Time Machine running and using Parallels, etc... so far so good.

I don't know what has happened or changed but my OWC 4GB ram hasn't had a lock up in over 4 days. My lock ups always occurred while watching video. I use my MacBook as my work computer by day and at home at night. Last night I watched two hours of video and had no problems.

I haven't done anything like a PRAM reset or anything. It just hasn't locked up sine the last time. I'm keeping my fingers crossed.

I knew I shouldn't have said it. 3 hours later and I have my first lock up in 4 days. Looks like I'm going to put the original 2 GB back in and get my memory upgrade from Apple.

My Crucial memory is still going after 34 hours too. After the first macbook fiasco with it's random shutdowns, I'm off to another fine start with this one. Hopefully this set will work as promised.

Well, no lock up yet, but I ended up rebooting to install a new 320GB HDD. Currently I'm at 6h 22m and have launched/closed all of my apps including a launch of XP with Parallels, run a DVD through Handbrake, done a 60GB+ TimeMachine backup, run a Spotlight index on the new drive and watched "3:10 to Yuma" via Quicktime. I suppose that about covers the usual memory hog suspects. I also have my wife logged in via quick user switching. We'll see if we can crash her.

My newly purchased MacBook 2.4GHz (4GB via Apple BTO) was also exhibiting complete freezes after as little as 30m operation. I eventually tracked the problem down to Time Machine performing its first backup over ethernet to a Time Capsule. Looking at Console logs is very helpful. Ended up using Time Machine with a USB connected disk instead.

I then ran memtestosx (in single user mode, overnight) to give me some confidence that memory was okay.

I bought the 4g upgrade from OWC and ran into the same issue with freeze ups on my MB Aluminum. While diagnosing the cause of the freeze, I found that 3g configuration using one of the original 1g ram in either slots works fine. I have exchanged the 2g rams to see if one of them are bad. But both worked fine in the 3g configuration. So I am thinking that there must be something certain the type of rams that do not work in the 4g configuration? I have a trouble ticket with OWC. May be with this many people having freeze issues, they may have have the answer for this.

I have found the exact same thing to be true... I have been running for 3days with 1x (1gb original stick) and 1x (2gb OWC stick). I think there is a flakiness above 3gb RAM

MBP 5,1 running fine on OWC 4GB since the 29th. So far no issues whatsoever.

I have found the exact same thing to be true... I have been running for 3days with 1x (1gb original stick) and 1x (2gb OWC stick). I think there is a flakiness above 3gb RAM

Spoke to apple support this morning. They claim that the ram from OWC lacks memory management, something like non-polarity in the old ram chips. So if one of the apple 1g ram is used, it works because it uses the memory management from the 1g chip. It seems to make sense. But I need to get OWC agree so that they can swap out the chip.

i went down to apple store last 2 day and ask for the original 2gb ram back. they allow me to refund the memory back. now im very happy no freeze at all within 2 days.i think mac got a problem...cuz even i upgrade verified memory but its still unstable.(apple singapore use Transcend for 4gb ram.the original is samsung)

i just got apple 4gb ram installed at the apple store. so far so good.

I actually paid $133 after tax to upgrade the RAM.. not sure how the discount worked out to that...