Computer won't boot with 32gb of ram

[wehler53]

Hey guys,

Ok so I'm having an issue with my computer not booting when all 8 slots of memory are filled, totalling 32gb of ram, however it will boot with 4 sticks totalling 16gb, any ideas why this is happening?

Thanks

 

[alexoiu]

Hi, Try testing each slot with single RAM module, to make sure that they work.

 

[Tradesman1]

What mobo and CPU? Do you have the latest BIOS and mobo drivers? Also, what set of DRAM, guessing you have two sets of 16GB (each 4x4GB), if so chances are good the two sets don't want to play nice - this can possibly be fixed with voltage/timing adjustments - let us know that actual model #(s) of the set(s) of DRAM

 

[wehler53]

I have an asrock x79 extreme9 (bios was updated yesterday) and an I7-4930k processor, I'm running windows 8.1 64 bit.

No the ram is all of the exact same model down to every last letter and number, they were all bought at the same time, (i.e.; 2 lots were bought) so they are compatible, I run it in the config of A1, B1, C1, D1 for the 4 sticks and it works perfectly but as as on as I put the next 4 in the dr debug function gives me the code b7 which means memory failure, I tried adding the ram in in each of the 4 remaining slots to see if any combo would work.. No luck

 

[alexoiu]

Then it might be a CPU socket bent pins issue or a short.

 

[Tradesman1]

2 packages (you said lots), if so that can be it, DRAM is packaged with sticks tested to work together, mixing packages has no guarantee and can (and often is problematic) even of the same exact model - also the XMP programming for sets is done based on the number of sticks, i.e. a two stick set might require an advanced timing for the tRFC of 208 while a 4 stick set might require 278, so having two 4 sticks sets may require DRAM voltage or timing adjustments and or MC voltage adjustment - what particular model DRAM

 

[wehler53]

Well it was actually 4 lots of 2

 

[Tradesman1]

Start with four sticks, one in each channel and set them to spec manually, see if that boots, if so go into the BIOS and raise the DRAM voltage + 0.06 over spec then find the MC (memory controller) voltage might be listed as VCC, VTT something like that, should be identified in your manual, and raise it to 1.2, then install the other four sticks and try

 

[wehler53]

Cheers mate, ill be sure to give that a go

 

[Tradesman1]

Let us know how it goes, will be around for awhile yet