Comments on: Running Tiger on a G5 Quad with 512 MB of RAM: Atrociously painful

By: Pierre Igot

Pierre Igot — Thu, 24 Aug 2006 12:14:56 +0000

Dan: Yes, I can see that, and I definitely don’t want to live with faulty RAM more than the minimum necessary. I suppose it’s possible that my RAM has been faulty for a while, so I don’t suspect that a few more days will make a huge difference. But it’s a concern, obviously.

That said, I seem to have identified the pair that contains the faulty module. (I have the other pair in right now, and I am not getting any freezes.) So there’ll only be a few more days of testing to determine which of the two modules is the faulty one.

Tiger with 2.5 GB of RAM on the G5 Quad with the two monitors is fine… But I suppose we all have different needs when it comes to RAM.

By: danridley

danridley — Wed, 23 Aug 2006 21:48:16 +0000

Faulty RAM can cause silent corruption of data files. If you save a file, and the version of that file in RAM has a few flipped bits because of faulty RAM, that corruption gets passed into the copy you just wrote to disk. No, it’s not likely, but it can be insidious, and it might not be visible — some strange behavior in a particular file that you don’t discover until months down the road might be traceable back to bad RAM.

And you’re right, dual-monitor Tiger in 512 MB is awful. I’m actually still somewhat RAM-starved on my MacBook with 2 GB, and I’m hoping the system will support 4 GB once the 2GB SO-DIMMs get cheap enough to consider.

By: Pierre Igot

Pierre Igot — Wed, 23 Aug 2006 12:22:46 +0000

Right, but if the RAM is not defective, you have to go through all the tests to make sure :).

By: matsw

matsw — Wed, 23 Aug 2006 09:37:32 +0000

Note that it is often not necessary to run all memtest’s tests to discover faulty RAM. When I had it, one of the first tests identified it in minutes.

By: Pierre Igot

Pierre Igot — Tue, 22 Aug 2006 16:44:04 +0000

Simanek: I am definitely relieved that the problem appears to be “only” with the third-party RAM and not with the G5 itself. While the RAM situation is annoying, at least it’s something that I can fix myself and I don’t have to take my machine to the local repair shop, which is a 6-hour round trip!

10.4 definitely didn’t bring any substantial performance improvements over 10.3. But it is not vastly slower than 10.3 on the PowerBook G4 Titanium with a 400 MHz processor and 384 MB of RAM. It’s still usable. I am of course disappointed that 10.4 didn’t continue the trend of further performance improvements over its predecessors, but I can also understand that the addition of new features such as Spotlight requires additional resources.

matsw: Thanks for the link. My computer froze during the night with the 2 GB that I had put back yesterday, so I switched to the other 2 1 GB modules. I ran memtest on these two modules this morning. It’s a very long process! (Took all morning, basically.) But after three passes it says everything is OK with these two modules, so we’ll see if the computer is stable in the next few days.

I realize that living with faulty RAM can be somewhat dangerous, but I don’t think the risk is that great. My impression is that the faulty memory can cause a freeze at any point, and it would have to occur at very specific points to actually cause damage to the file system, wouldn’t it? The likelihood of this is not very high.

By: matsw

matsw — Tue, 22 Aug 2006 08:57:31 +0000

Testing RAM this way is crazy. It is very time consuming and can lead to a bad filesystem: think that eveything written to disk goes through a buffer in RAM. If the data in the buffer is corrupt, so is the data on disk. Go to http://www.memtestosx.org/ and get memtest. I had a faulty RAM module once and it was diagnosed in seconds. I am not sure memtest will tell you which module is at fault, but it will identify a RAM problem much quicker than waiting for a crash to happen, and your testing time will be much shorter.

By: Simanek

Simanek — Tue, 22 Aug 2006 00:36:28 +0000

And sorry to hear about your RAM. That sucks, but I’m sure you were fearing something far worse.

By: Simanek

Simanek — Tue, 22 Aug 2006 00:34:16 +0000

I have Panther running on an original iMac with 128MB of RAM and a Lombard PowerBook with 512MB of RAM. The iMac is a bit painful but fine for surfing the web on dial-up. The PowerBook is really fairly decent if you stay away from YouTube. Just thought I’d throw this out there. I think Panther is an excellent OS. Apple had finally worked out many of the kinks and it still remained reasonably lean on hardware demands. I would hate to see what Tiger would do to the iMac (yes, I realize it’s not supported hardware for even 10.3). I just started working on 10.4 at work with a dual 2GHz G5 and I have to say that, aside from it’s improved native interaction with Windows networks, I am not impressed. It’s even slower than the same hardware running Panther in certain network file situations. I’d be curious to hear your perspective on Tiger compared to its predecessor.