Q: My Mac Pro spontaneously restarts

Hello Hatter,

Thanks for the suggestions...I haven't tried running with just one module on the "A" card because I am running CS5 mostly and it requires too much ram to efficiently run on anything less than 2 gigs...so I've had two 2 gig modules on that card and after running successfully for hours yesterday, decided to see if placing two more modules on the same card would affect anything. It didn't seem to, Everything kept running smooth, though not discernibly any faster...because the second processor wasn't in play.

I haven't tried placing ram on the second card in unsupported positions....but may if it comes down to it!

be well,

john

Well, 48GB of RAM is known to help! <g>

But the placement on Risers has no relation to processor. There is no way to diable a processor by having RAM in or not in Riser B, or second memory bank in 2009+ Nehalem based systems.

But it is possible in systems that use DDR3 (you use DDR2) to use a single DIMM... for purpose of memory testing.

For you, you want 4 x 4GB across both Risers, or 8 x 4GB to give CS5 RAM it wants.

Hello Bob,

I think you may be right about communication between the power supply and the rest.

Maybe a new one will fix it as plainhat has suggested...i hope...or maybe better even just a good cleaning, about to do that right now, so I'll keep everyone informed.

But if that communication issue is due to something else as you suggest- some flaw in the sensing and signaling- die to some other malfunction somewhere else along the line, then I'm sure not going to order another MB to see if that fixes the issue. I'll just have to limp along on this one with one processor and hope it doesn't all go down on me... or order another.

So here goes!

Thanks to everyone, I'll report back soon,

john

Hello Hatter, My MP is a late 2007 model...300GHz quad, I was always under the impression that each ram card module supported its respective processor, one ram card for each processor, thus the reasoning behind installing equal amounts or ram in paired positions on each card- so each processor would have equal processing power.

Is that not so?

Do both processors run with ram on just one card?

How could that be so?

I started with a 2x2, 2 gigs in each ram module and then went to 4x4, 2 gigs each, 8 total, worked wonderfully for years, until about 48 hours ago.

Now I have 4x1, with no card in the "B" slot.

And I've also run it with just 2x1, in the "A" card carrier.

But as soon as I put anything in the "B" slot, that's when the trouble starts.

Not so.

And the worse part is the DIMM slot 3 & 4 share the bandwidth of 1 & 2 adding latency by a bit.

Symmetrical Memory Performance

Barefeats has some numbers also.

processors always run as long as it boots, so with one pair of DIMMs.

So, you are probably buying a replacement Riser to see if that works? yes? but only after you determine that your "Riser A" removed and put "B" in top spot does or does not work. Otherwise you have motherboard or some other issue.

And you have taken a pair of DIMMs of the 4 x 1GB and put them on lower Riser and it fails.

Q: 4 x 4, 2 gigs each

Me: that doesn't give me a picture but 8 x 2GB does.

FBDIMMs fail. Heat, old age, running warm, not getting cooled down before opening side door, dust, not boosting the fans to never fall below 800-900 rpm.

The 3.0GHz probably kicks up a little more heat of its own, and could use more power. The 2007 8-core 3GHz I think did use a stronger PSU in there.

Xeon processors have feature to support quick-link path to share data. A single socket 2010 6-core does have an advantage in not having to rely on Q-Path for data, and you can have 3 x 16GB in there.

I would have bought some RAM to test with, have run AHT and Memtest along with Rember. $70 for a Riser, too.

I read a lot of these posts last night, as I have recently begun unplanned restarts (some one after another). MacPro 2007 30" monitor. 16GB RAM. Looked at my ram, looked fine. I turned off sleep, and did a variety of other things- leaning towards the might be software idea... esp. might be Safari.  Right before my computer would restart it would make two sounds like the 'closing shutter' sound on 'SnapzPro', which also might be some kind of wierd software glitch. Then I moved my dock which was pushing the upper edge of the left corner where I had a 'hot corner' for turning on screensaver. Changed hot corner. Then dumped a lot of old software (older versions of Adobe Creative Suite). Took all unnecessary icons from dock- and all I can report is since last night it has not done a restart one time, and seems to be working fine. The only other thing to report is prior to the problems with restarting, I had to dump all my fonts out of 'Suitcase' and upgraded to the new version. Appreciate all the posts, and will keep all in mind. Particularly replace power supply. New to discussion.

I recognize the shutter sound. I had the same thing during a stage of these symptoms. Power supply slowly going after 4+ years ended up being my issue. I was out of warranty, and the genius guys still took it in for free. They told me that I would only have to pay if they figured out what was wrong (which they did) and if I agreed to the replacement of whatever hardware part that needed to be replaced (in this case $180 for a new power supply plus the flat $40 fee of installating whatever hardware).

My Mac is back!

Really hope that everyone manages to track down their issues, it feels pretty crummy mentally, not being able to count on the machine to stay on while you are working....

/Christian

Ahh man...I knew that tarck of thinking just had to make too much sense!

OK, so it looks like I have a motherboard or maybe power supply issue...because I have switched the risers around- using A or B in the first slot and all goes well, and I have mixed the ram between the risers (using one or both- still experience unexplained auto restarts), and I have mounted two 2 GB modules on the same riser and mounted four 2 GB modules on that riser- without a problem- as long as just the one riser is installed.

To confirm (my apologies) the 2x4 was for each riser, so yes 8x8 total.

Just to make sure it wasn't likely a heat issue that could be cured by cleaning I took the whole thing apart yesterday: removed all four hard drives, the optical drives- where there was dust I hadn't got at the first time around as it was inside the case, and same went for the power supply, took out the PCI cards and graphics card and the risers again, and cleaned and remounted everything.

It sure looks nice and new inside, maybe I can sell it to someone? HAHA just kidding, I wouldn't do that to anyone.

All that and as soon as I opened an image file and asked it to get busy_ bam_ restart.

Took the second card out, and worked with it the rest of the day, no issues.

As long as I'm not running CS5 in conjunction or at the same time as other software I'm not noticing a lot of

loss in performance, a bit but not too much, especially when processing individual files one at a time.

Because I've tested the ram in so many different configurations I'm pretty sure that's not the issue. Also, it all shows up when mounted and tested out OK.

Now I can only find one place to get a power supply (about 270.00 US), the others guys sold the one they had, do you know of others?

This place told me there was a 25% restocking fee if it didn't turn out to fix my problem, plus shipping both directions, equals 225.00 to take a chance on if that will be the fix...or not.

What are "AHT" and Rember?

Thanks for your continued support!

You have a big heart and a ton of patience dude!

Museum, I'm glad that worked for you. but I'm not running Safari with this unit, it doesn't even get connected to the internet, to keep it safe. That way I don't need to run near as much protection.

Unfortunately for me I booted from two different drives with two different OS, as that was my first thought.

As well as running different software and applications on different drives with different OS and still had the problem.

Thats what made me throw up my hands and get on here to see if others had this issue too and what might have worked for them as fixes.

Also I have turned off sleep for both the display and the drives and thought I turned off auto restart- unselected the box for that in pref-energy saver-....but it still dies and then restarts whenever it feels like it, sometimes in rapid succession, but only when two risers are installed, take one out and its OK.

Thanks for the post and GOOD LUCK!

Christian,

What Mac store did you go into and get a power supply from, for $180.00?

I think that might be my problem too and if its not, its looking like it may be the motherboard, which would mean

a new machine, cuz I'm not laying out that much on a bet.

I can't take mine in to the closest Mac Store cuz its 1000 miles away, and shipping it there and back, forget it.

But since I just took my power supply out and cleaned it, I feel pretty confident I could replace it with a new one.

It is a hassle though, you have to remove all the hard drives, then the optical drives and then four screws that aren't near as easy to get to, and then you can shift it over and pull it out.

Shoot if I had a local MacStore I'd pay them $40 to do it after going through it once myself.

Here;s one everyone can get a laugh from: I pulled just about everything out and did a major clean yesterday and then put everything back in and pushed the power button.

The little light on the display and the CPU light up but nothing else happened!

Kinda put a little fear into me...had to pull the plug to shut it down.

Then I glanced over at the table where I'd laid the two risers and there was a "lump" next to the one I had intentionally left out...HA.. Opps...it was the other riser!

HA HA HA, yes, OK, I,DID IT.

Put the riser back in and all was well.

Except when I put the second one in.

Back to square one!

Glad yours works, maybe a PS will do it for me.

Snow Hound

I'm in the UK but if you can't get a PS economically in the US, it may be possible to get one shipped? I got mine at my local Applestore for £120 including fitting. Here's the link:

http://www.apple.com/uk/retail/festivalplace/

Two weeks with the new PS so far and there's a beautiful silence coming from my office this Sunday morning where there used to be endless restarts.....

AF

DVWarehouse in USA:

http://www.dvwarehouse.com/Mac-Pro-Power-Supply-c-247_4884.html

Thanks Christian-

Of course, later in the day I had restarts again!!! I schlepped it to the Mac Store genius bar last night... they said everything looked fine- although I explained that it didn't happen all the time.

The genius did explain something I didn't know- which is 10.6.8 (Snow Leopard) is up in the realm of Lion OSX (our work tech guys have said too many bugs to upgrade yet) and described the 32/64 bit new feature of Lion. He thought it was caused by old software conflicts (I kept bringing up all I read on blog and your point about it being the beginning....). We left it I brought CPU home, and they're ordering a Power Supply and 'accompanying board' so it will be in stock in case I have a total failure- thereby not waiting 5-7 for fix.

He explained that if you hold the 2 and 3 keys down simultaneously on startup that system will revert to 32 bit mode- or basically run the way it used to run... thereby limiting those extra software issues.

That actually may explain why I suddenly had to dump all my fonts from Suitcase- and then end up upgrading to the Fusion 3 that runs with Lion. Oh well, would have to do that anyway.

One question here- did you only have to replace the power supply, and not the board? The board is a $470.00 item, which makes it a bigger upgrade. Sigh.

Otherwise, everything working beautifully.

Another genius said 'don't believe everything you read on the blog'... of course I take it all with a grain of salt, but when someone knows your exact symptoms...

They also mentioned a test they can do overnight called 'sleeping kitty'- that puts to sleep, wakes up, puts to sleep... but the other genius said that if you're having issues- running that test can make problems speed up. Familiar with Sleeping Kitty?

Thanks for your help.

THANKS, looks like I may be giving em a call.

cheers,

john

Sorry to hear you had relapse.

I'm still running Snow Leopard so I have no experience with Lion.

But in a pinch you should try pulling the "B" riser out and running on just the "A" card.

Its not the best solution, but it's working for me until the right one comes along, hopefully.

No issues with unrequested restarts for me with the one riser ( in my instance it has to be removed from the computer, taking the ram out and leaving it in doesn't work for me).

I don't know why its working, because either riser works fine regardless of the ram modules installed on it or which riser is mounted.

good luck,

john