Mac Pro 4,1 w/X5670 RAM stuck at 1066

[DEMinSoCAL]

Just upgraded my Mac 4,1 (firmware updated to 5,1) and put in my X5670 CPU. Everything went great (single CPU Mac, btw).

After everything came up and looked good, I shut down and removed the original RAM (1066 ECC). I popped in 4 x 4GB PC312800 (DDR3-1600) modules. Turned on and system started but shows 1066 still.

I reset the PRAM, but since I have a non-Mac Graphics card, I can only go by what I hear. I turn it on, then press the OPT-CMD-P-R and hold it down. I hear the first BONG. Then, about 30 seconds or so, a second BONG and I release the keys. System comes back up, but still 1066. I don't see that anything reset, per se...is there a way to tell if the PRAM reset?

What is some decent 8GB DDR3-1333 modules that people are using?

 

[h9826790]

Try only use slot 123, the 3x4G should may give you 1333MHz, this is a known issue.

 

[Macsonic]

Just upgraded my Mac 4,1 (firmware updated to 5,1) and put in my X5670 CPU. Everything went great (single CPU Mac, btw).

After everything came up and looked good, I shut down and removed the original RAM (1066 ECC). I popped in 4 x 4GB PC312800 (DDR3-1600) modules. Turned on and system started but shows 1066 still.

I reset the PRAM, but since I have a non-Mac Graphics card, I can only go by what I hear. I turn it on, then press the OPT-CMD-P-R and hold it down. I hear the first BONG. Then, about 30 seconds or so, a second BONG and I release the keys. System comes back up, but still 1066. I don't see that anything reset, per se...is there a way to tell if the PRAM reset?

What is some decent 8GB DDR3-1333 modules that people are using?

Hi. You mentioned in your post the ram model PC312800 (DDR3-1600). As far as I know the correct model has to be PC3-10600 at 1333Mhz ECC unless I am mistaken. Maybe your Mac Pro downgraded the speed to 1066mhz upon reading that the model is a different one.

 

[flowrider]

MVC did not have the same experience. He got 1333MHz.

Just want to point out that the myth that W3xxx Mac Pros can't use 4th slot has been busted a few times already.

I use 3 @ 16 and 1 @ 8 and get 56Gb running at 1333. If it has actually downclocked itself to 1066 it doesn't know about it.

Not necessarily relevant to OP but I like to add it anywhere I see the "max is 48gb" myth typed out. It is tough to break the inertia of an oft repeated old wives tale but I think it is worth trying. Replacing the W3690 with an X5690 would allow 64gb if that ever is needed.

However, I would try just using three slots (1, 2 &3), and see what it shows up as. Remember, the CPU uses 3 channel memory, and slots 3 & 4 share the third channel.

Lou

 

[h9826790]

Hi. You mentioned in your post the ram model PC312800 (DDR3-1600). As far as I know the correct model has to be PC3-10600 at 1333Mhz ECC unless I am mistaken. Maybe your Mac Pro downgraded the speed to 1066mhz upon reading that the model is a different one.

PC-12800 is fine, as long as only use 3 channel, they can run at 1333MHz.

 

[DEMinSoCAL]

Try only use slot 123, the 3x4G should may give you 1333MHz, this is a known issue.

That seemed to fix it. 3 modules do run at 1333.

So, am I stuck at using 3 modules or are there modules where I can use all 4 slots and still get 1333?

Thanks, everyone, for the tips and help.

 

[mikeboss]

I usually only run 3 DIMMs in each of my Mac Pros. but for fun I tested it once with four modules and much to my surprise they ran at 1333 MHz. to be 100% sure before posting an answer to your question, I retested this a few minutes ago. same result, they all work at 1333 MHz.

these are the DIMMs I use: Kingston KTA-MP1333/8G

http://www.kingston.com/us/memory/search/?partid=KTA-MP1333/8G

 

[DEMinSoCAL]

I usually only run 3 DIMMs in each of my Mac Pros. but for fun I tested it once with four modules and much to my surprise they ran at 1333 MHz. to be 100% sure before posting an answer to your question, I retested this a few minutes ago. same result, they all work at 1333 MHz.

these are the DIMMs I use: Kingston KTA-MP1333/8G

http://www.kingston.com/us/memory/search/?partid=KTA-MP1333/8G

Thanks. That's looks like ECC memory. I'm wanting to go "on-the-cheap" and get non-ECC. I don't really need the ECC functionality (or cost).

 

[malcbo]

Hi,

FYI, I upgraded the memory on my Mac Pro 4.1 (also upgraded to 5.1 and X3690) and bought 2 sets of Kingston KVR1333D3E9SK2 (2x8GB).
They memory (4x8GB) is running at 1333MHz after resetting the pram.

 

[h9826790]

So, am I stuck at using 3 modules or are there modules where I can use all 4 slots and still get 1333?

I have exactly the same problem. Use some cheap non-ECC ram (ADATA 8G PC-12800), only 3x8G can run 1333MHz, 4x8G will run at 1066MHz.

However, you should not able to feel any difference between 1333 CL9 and 1066 CL7. The main speed difference is coming from running the RAM in triple channel or double channel, but not 1333 or 1066. As long as you use all 4 slots, there is almost no real world difference.

 

[DEMinSoCAL]

Does anyone have 4 x 8GB modules of non-ECC RAM (standard modules), all successfully running at 1333?

I'm wondering if, using cheap non-ECC, 24GB is the most or is there some brand that will run all 4 modules?

Thanks.

 

[MacVidCards]

Perhaps this is another aspect of the issue where I can use 3 @ 16 gb & 1 @ 8 with a w3xxx and 4 @ 16 with a x5xxx.

If you are really using an X5 series CPU then we have learned another piece of puzzle

 

[Ironjer]

Does anyone have 4 x 8GB modules of non-ECC RAM (standard modules), all successfully running at 1333?

I'm wondering if, using cheap non-ECC, 24GB is the most or is there some brand that will run all 4 modules?

Thanks.

I'm using 4x8GB Corsair XMS3 at 1333Mhz running good but when a turn off the mac for long time missing 8gb (red light on board) then reboot and all ok again just happens when you turn off the mac for more 4-5 hours i changed the cmos battery but doesnt work and tested each memory all is ok. Maybe the NON ECC is the problem i dont know. Overlay all working good no memory error running.

PD: running in Mac Pro 5,1 with 2xX5650

 

[DEMinSoCAL]

Perhaps this is another aspect of the issue where I can use 3 @ 16 gb & 1 @ 8 with a w3xxx and 4 @ 16 with a x5xxx.

If you are really using an X5 series CPU then we have learned another piece of puzzle

I am using an X5670, but only 3 modules work @1333. 4 modules it bumps down to 1066.

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I'm using 4x8GB Corsair XMS3 at 1333Mhz running good but when a turn off the mac for long time missing 8gb (red light on board) then reboot and all ok again just happens when you turn off the mac for more 4-5 hours i changed the cmos battery but doesnt work and tested each memory all is ok. Maybe the NON ECC is the problem i dont know. Overlay all working good no memory error running.

PD: running in Mac Pro 5,1 with 2xX5650

Do you have the part number for the modules you are using?

 

[Synchro3]

I'm using 4x8GB Corsair XMS3 at 1333Mhz running good but when a turn off the mac for long time missing 8gb (red light on board) then reboot and all ok again just happens when you turn off the mac for more 4-5 hours i changed the cmos battery but doesnt work and tested each memory all is ok. Maybe the NON ECC is the problem i dont know. Overlay all working good no memory error running.

PD: running in Mac Pro 5,1 with 2xX5650

I think i have the same problem after installing a Xeon W3690, DIMM 3 disappeared: https://forums.macrumors.com/showthread.php?p=19460782#post19460782

But my three DIMMs are all identical (ECC, registered, 1066 MHZ). However, the last three day 4 days it did not happen again, maybe because i did not turn off the mac for long time. Have to observe this.