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Mac Pro (4,1 to 5,1) CPU upgrade

Probably such a mistake to try to tweak CPU A into 4 ram slots BEFORE putting B on. Now I'm back to no space between the flashing white front LED no boot and the RED CPU A diag led, full fan no boot.

Plus, there's a red diag led under the HD1, where the diag trickle power, power LEDs are, when this happens, until I pull power and start again.

I HAD THIS MOTHER BOOTED at 3.33ghz and TWO STICKS OF RAM GOD DAMN IT!
 
You're getting closer fella - just add an hour at a time and it will come good. Some work pretty quickly, work over probably nearly a full turn and some are a pita you have to get them just right. Add an hours turn at a time.

Doing it earlier in the day definitely recommended than doing it late at night too when patience levels are low!
 
Key question is - when I tighten past the blinking white front LED to the point where I get red CPU warning led, and full fan - do I then continue to tighten, or back off?

I'm following the Pindelski guide, which basically didn't address the red light, but says

"If you get a flashing white diode on the front panel of the Mac Pro but no chime or login screen, pull the processor cage and tighten each bolt 1/4 turn on the heat sink. Try again. If you get a solid white LED and no start, remove the processor cage and loosen each bolt 1/8th turn. If still no joy, remove the heat sink, check the CPU socket for crushed pins

I haven't been able to decide if I should turn BACK from there, looking for the sweet spot, or turn FORWARD from there, in case I haven't been brave enough.
 
ah man i feel for you, this must be a killer! if i had a spare logic board and CPU i would try and replicate the problem you have, its like the boot you had gave you that ray of hope and now back to misery...

just for clarity is it safe to say you do 3 full turns (gauging the start of the turn by turning bolt anti clockwise until 'click' then start counting from there) tightening in the figure of eight motion, then do another half? 3/4 turn from there?
 
CASLondon said:
Key question is - when I tighten past the blinking white front LED to the point where I get red CPU warning led, and full fan - do I then continue to tighten, or back off?

I'm following the Pindelski guide, which basically didn't address the red light, but says

"If you get a flashing white diode on the front panel of the Mac Pro but no chime or login screen, pull the processor cage and tighten each bolt 1/4 turn on the heat sink. Try again. If you get a solid white LED and no start, remove the processor cage and loosen each bolt 1/8th turn. If still no joy, remove the heat sink, check the CPU socket for crushed pins

I haven't been able to decide if I should turn BACK from there, looking for the sweet spot, or turn FORWARD from there, in case I haven't been brave enough.
Click to expand...

That guide is correct - but break the quarter turn into thirds of a quarter which is the hour mark on a clock. Back off, use the smaller increments instead then treat yourself to a nice beer when you've hit that sweet spot called bong!
 
lexR said:
ah man i feel for you, this must be a killer! if i had a spare logic board and CPU i would try and replicate the problem you have, its like the boot you had gave you that ray of hope and now back to misery...

just for clarity is it safe to say you do 3 full turns (gauging the start of the turn by turning bolt anti clockwise until 'click' then start counting from there) tightening in the figure of eight motion, then do another half? 3/4 turn from there?
Click to expand...

I'm doing 3 full turns, then a 4th turn, per the guide, then I'm booting - getting flashing white (I'm assuming memory read failure=too loose), then I'm ratcheting up little bits of turn (always 4 bolts together even though they feel different in tension), trying to boot, going back, adding bits of turn. So in total, my turns are probably in the 4.25-4.5 range

Then, getting the red light, fan, no boot.

NOW i need help deciding if I should keep tightening, or back off. I have backed off to date in small increments, only getting back to the white flash front led
 
Well I can only go from my experience in doing this CPU swap and I would say do the 3 full turns then a half turn on each and try different set of ram modules and start from there as I never got to 4 full turns I started at 3, then a half turn on each and it booted straight away, I then turned then a further 1/4 turn as still far away from washers but still only just got over the 3 and 3/4 turns, but every machine, CPU, heat sink and tolerances are different, keep going buddy
 
Well, news.

I did CPU A over again from scratch, 4 sticks of ram. 4 turns. BOOT on the FIRST GO. All memory recognised. Did not touch again, powered down.

Did CPU B

No boot, solid white led. Hmmmm. I am damn close, but go back to the starting point every time. SHouldn't it still boot if only CPU A is good?
 
CASLondon said:
No boot, solid white led. Hmmmm. I am damn close, but go back to the starting point every time. SHouldn't it still boot if only CPU A is good?
Click to expand...

Don't think so. Just like a faulty RAM can cause no boot even though all other RAM are good. Unless your CPU is really loose and the CPU board detect nothing on it. Otherwise the machine should able to detect that there is a faulty CPU (due to poor connection), give you some indication (white light), and no boot.
 
Success

Added down turns for a while on CPU B, and....

BOOT - dual x5680, 24g ram, geekbenching 64 bit over 30,000. Whoo hoo.

After geek bench finished, the fans started running hard and still are. Is that normal, or a sign of something? I gave it 5 minutes of fans, then put it to sleep manually

I need to fill the last ram slots and stress test this beast I assume, and add fan/temp/stat monitoring software. Suggestions?
 
CASLondon said:
Success

Added down turns for a while on CPU B, and....

BOOT - dual x5680, 24g ram, geekbenching 64 bit over 30,000. Whoo hoo.

After geek bench finished, the fans started running hard and still are. Is that normal, or a sign of something? I gave it 5 minutes of fans, then put it to sleep manually

I need to fill the last ram slots and stress test this beast I assume, and add fan/temp/stat monitoring software. Suggestions?
Click to expand...

If fans running wild I would suspect the temp sensor connector not seated down securely. Making that connection while placing the heat sink onto the 4 bolts is the tricky part IMO, as it's just too easy to wobble the heat sink on the processor plate underneath, so much care needs to be taken while fiddling the temp sensor connector into place.

In some ways a 2nd pair of hands is useful here. One set of hands hold the heat sink level but not resting on the processor while the other set of hands gently ease the connector into position and firmly pressed into its receptacle.

No matter, good luck. I've done this upgrade to three MP4,1s to date and was successful in each case.
 
CASLondon said:
Success

Added down turns for a while on CPU B, and....

BOOT - dual x5680, 24g ram, geekbenching 64 bit over 30,000. Whoo hoo.

After geek bench finished, the fans started running hard and still are. Is that normal, or a sign of something? I gave it 5 minutes of fans, then put it to sleep manually

I need to fill the last ram slots and stress test this beast I assume, and add fan/temp/stat monitoring software. Suggestions?
Click to expand...

Great news glad you kept at it, fans constantly running seems odd normally like said one of the fan connections not seated properly?

Good news thought
 
The fans ran hard after running Geekbench 3, for 5 minutes afterwards. I let it run a bit, then put the box to sleep.

Woke from sleep a few minutes later, its all normal fans. So I'm assuming the connectors are seated, as they would run full time full speed if they weren't, right?

I'm just assuming Geekbench ran them hard, I'll put more ram in and Geekbench stress test it later on. I want to rest on my laurels for a while.
 
CASLondon said:
The fans ran hard after running Geekbench 3, for 5 minutes afterwards. I let it run a bit, then put the box to sleep.

Woke from sleep a few minutes later, its all normal fans. So I'm assuming the connectors are seated, as they would run full time full speed if they weren't, right?

I'm just assuming Geekbench ran them hard, I'll put more ram in and Geekbench stress test it later on. I want to rest on my laurels for a while.
Click to expand...

Yes, it's normal for Geekbench to run the CPUs and RAM 'hard' and the fans are needed to hold the temperatures below the operating limits.
 
Success!!!!!!

4,1 2.26 octocore --> 5,1 2.93 12-core (X5670)

Followed Pindelski's directions to the tee.

Only difference:

1) 3 rotations and then test for each tray

Finals:

CPU A: 3.5 turns
CPU B: 3.0 turns

Currently 48gb at 1333MHz (Six 8Gb sticks).

If I upgrade memory later and it does not show, I still have wiggle room to the 4.25 turn max.

Total time:

3 hours -- with my 7-year old son and 5-year old daughter asking me 'what's this', and 'what not'

Mr. Pindelski: THANK YOU!!!🙂
 
I used washers on the heat sink posts, as some people suggest, and it all worked perfectly for me the first time. And I'm an idiot.
 
A CPU runs faster when its cooler than when its hotter.

For any CPU with turbo boost potential, whether, when, how frequently and how long that occurs depends on CPU temperature, current draw and watts used. For any CPU with turbo boost potential in a MacPro, the only factor that the user can directly control is the CPU temperature. So if you want to improve system performance under heavy loads (such as running Geekbench, rendering etc.), then use a free fan control utility like SMC fan control to keep your system as cool as your ears/comfort allow. That utility also helps to keep the PCIe compartment to stay cooler and thus can improve the performance of you GPU(s). Cooler components also last longer.
 
Another thing to note on 4.1 --> 5,1

So I did the upgrade as I mentioned previously, and everything was great. I bought an additional two 8 GB 1333MHz sticks from Ram Jet to increase my memory from 48GB to 64GB. Lo and behold I get the flashing white LED on the power button and no start-up screen/

I am thinking that I need to tighten the screws maybe a quarter turn....

Disaster ensues -- I do that -- I loosen an eighth, etc, etc, etc -- I get red LEDs, I get solid white, but no boot-up screen -- I am thinking, what the hell!

I go back to my notes, remove the additional sticks, unscrew, and rescrew back to 3.5 turns on all 8 screws. Computer boots up just fine.....

I call Ram Jet. They are reputable, and I ask what the hell is going on. They tell me to try just those two sticks on slots 1 and 5. Ha! The thing boots. So he tells me it is because I am using registered ECC memory -- Apple specs require Unregistered ECC memory. So they will take back their Apple spec memory and do a straight swap to registered ECC memory and that should fix the problem.

This back and forth to add an additional 16GB memory ate at least three hours of my time after a totally successful conversion to dual X5670s. Geez.

So if you are like me and you bought a 4,1 to convert to a 5,1 -- beware of the memory that came with the computer -- it might not be Apple spec, and it may not work with additional memory that is actual Apple spec.

If I was going to do this again, I would have made sure to upgrade the memory first to make sure everything was running perfectly before doing the swap. It would have ruled out a lot of the problems I had and saved me a lot of time and stomach lining. 😕
 
Funny you mentioned that.

I got through the above saga upgrade, all repeatedly booting as 2 x 3.33, 24G of ram in slots 1-3 and 4-7.

I put my MacVidCards wi-fi AC/ bt 4 upgrade kit in today, and when I reseated the processor tray and booted, I can only see DIMMS 1-3, 12G.

Tried again, and still, only half the ram from CPU A, none from B, but both processors are running.

WTF?//?????!!?!?!?!?

I don't know whether I should worry, or get back in there with the hex and tweak again. All this ram booted fine before, both before and after the CPU upgrade.
 
yes, 5 through 7. System profiler shows them as empty slots now

I was booting with the side panel on, since I thought I was past any wrinkles.

I have to fly with this baby across the Atlantic tomorrow, I'm just going to worry about it in a couple of days. In the meantime, I can't decide how worried I should be or not be
 
Last edited:
Are the Red Diagnostic LEDs on? They come on (if there is a fault) when you boot the machine and stay on until the machine is turned off. So you can open the side panel and look while the machine is running.

Lou
 

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