memory slots failing - Is the memory controller on the motherboard or in the CPU (Intel 3930K CPU, X79 chipset)

x509

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What I want to know is where the memory controller is and why the memory slots are failing. I'm asking because I want to sell the board and CPU, but only if the parts are good. Here is why I'm asking.

My current system is built around an ASUS P79Pro motherboard with an Intel 3930K CPU. FWIW, it has never been overclocked. I built this sytem with 4 x 8GB RAM sticks. The motherboard has 8 memory slots, and is quad channel. I populated slots A1-D1. Slots A2-D2 would be used if I wanted to add more memory sticks, which i have never done.

The system was stable for years until about a year ago, when the Control Panel System applet reported only 24 GB and then only 16 GB. I spent too much time with Memtest86 trying to find 2 good memory slots for A1-D1. That was maybe six months ago. Now System applet reports only 8 GB system memory. (I'm planning to replace this board with an ROG Strix-E X570 and AMD CPU quickly.)
 

Denpepe

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The memory controller is on the CPU, but that does not mean everything, some boards warp and as such make bad contact or the cooler might be aplying uneven pressure, you could try reseating the CPU to see if that does anything, don't overtighten the cooler
 

vick1000

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Memory errors are commonly due to voltage flux that is out of spec for the chips, thus could be the RAM itself, the controller, or the motherboard, even the PSU lower voltage rails.
 

viivo

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Look at the socket pins from different angles with a bright light. Also check the bottom of the CPU in case some thermal paste made its way onto the contacts.
 

x509

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Memory errors are commonly due to voltage flux that is out of spec for the chips, thus could be the RAM itself, the controller, or the motherboard, even the PSU lower voltage rails.
I tested out all four memory sticks in a known good RAM slot, and all four are good. I used memtest86
 

x509

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Look at the socket pins from different angles with a bright light. Also check the bottom of the CPU in case some thermal paste made its way onto the contacts.
OK, I plan to do that as soon as I can. I'm also resigned to the fact that I need to replace the motherboard/CPU and RAM very soon. I hope to sort out all my choices in 2-3 days and order parts.
 

Furious_Styles

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OK, I plan to do that as soon as I can. I'm also resigned to the fact that I need to replace the motherboard/CPU and RAM very soon. I hope to sort out all my choices in 2-3 days and order parts.
Probably do need to replace it. Unless you can use C and D slots without issue. Lots of times only one bank of memory fails.
 

thesmokingman

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Keep in mind that systems don't run forever and eventually their lifespan will fall off a cliff. My old RIVE ran forever it seemed then issues cropped up fast. First the cpu header died, luckily I still had the cpu opt header. The the soundcard let go, switched to a soundcard. And this board was under water its whole life.
 

x509

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I'm talking about memtest.
Yes. Memtest is what I have been using in various rounds of RAM stick/memory slot testing. Frankly I've spent too much time doiong all these tests on a motherboard/CPU/RAM that needs to be replaced. I still intend to do the tests in post #2. If that fixes the system, I may keep the motherboard for spare/backup use.
 

vick1000

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Yes. Memtest is what I have been using in various rounds of RAM stick/memory slot testing. Frankly I've spent too much time doiong all these tests on a motherboard/CPU/RAM that needs to be replaced. I still intend to do the tests in post #2. If that fixes the system, I may keep the motherboard for spare/backup use.
I am saying memtest is a waste of time. Better of testing single sticks in single slots with Prime blend.
 

Wooshoo

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I am saying memtest is a waste of time. Better of testing single sticks in single slots with Prime blend.
So I have heard for years that memtest86 is gospel. What changed and is there a particular reason to use blend in prime rather than large fft? How long do you run until you consider it good?
 
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