2 DIMM slots not recognized - could it be a processor issue?


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Hi, I've been having a bit of an issue with the memory in my new-build.

I'm using an Asus X99-WS/IPMI, which has 8 DDR4 slots.

However, nothing gets recognised in slots A01 & A02. I did the usual trouble shooting, swapping ram around, trying known good ram from my other system etc, but it just wouldn't recognise it.

The system would boot (unless only these slots were populated), but anything in those slots would just be ignored.

 

So I returned the motherboard thinking it must be a mobo fault. But the new board has the same issue.

 

Could it be a processor issue, or some other compatibility issue I've not spotted?

 

It's a Xeon E5-2603v3 - which support 4 channels of DDR4. I'm using 4x 4gb Crucial Ballistix DDR4 2400 16-16-16-39 1.2v (non-ECC) ram

 

If I put the 4 sticks in any other combination of slots, it works fine - but nothing from A01 or A02

 

So could it be a processor issue instead, or am I unlucky enough to get two faulty motherboards (from different vendors)?

Edited by extrobe
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2 hours ago, jonathanm said:

What HBA's (if any) do you have installed? Try removing ALL cards from the PCIe slots to see if the behaviour changes.

 

I have 3x H200's.

 

I'll try pulling them out in the next couple of days, see if it makes a difference.

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I had issues with my Gigabyte EP45 board when trying to use more than 2 RAM slots or 4GB of RAM (can't remember all the details) and it required some monkeying around in the BIOS to allow the machine to POST and function normally.

 

Maybe there's a known issue about more than xx GB of RAM on your board, or using more than two slots at a time?  I sure would hope not given the quality I expect from a board like that, but stranger things have happened.

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5 hours ago, bman said:

I had issues with my Gigabyte EP45 board when trying to use more than 2 RAM slots or 4GB of RAM (can't remember all the details) and it required some monkeying around in the BIOS to allow the machine to POST and function normally.

 

Maybe there's a known issue about more than xx GB of RAM on your board, or using more than two slots at a time?  I sure would hope not given the quality I expect from a board like that, but stranger things have happened.

 

Thanks bman - it will always post fine (unless only A1/A2 is populated), and it will still recognise 4 slots in a different combination (eg, I'm using something like C1,C2,D1,B1) - just ignores the very presence of A1 & A2

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19 minutes ago, johnnie.black said:

The Dell h310 can cause that in some boards, so the h200 is probably the same, if it works without them search for h310 tape mode to fix it.

 

Interesting, thanks - I'll check that out - was up until 3am getting the replacement board + flashing the new H200 (made a right ballsup of the flashing!), so will probably give it a day or 2 before I do that, but will certainly check it out, thanks.

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2 hours ago, johnnie.black said:

Was on phone earlier, so not easy to search, but here's the thread for the tape mode if you need it:

 

 

 

Interesting, as that thread also mentions dimm slots being deactivated. Certainly will give it a go - I'd actually already taped one of them up, as I was trying to flash it from another pc, but was having none of it, even with the tape added.

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I finally got around to giving this a go. Pulled everything from the system, except the ram. Still can't utilise the 2 slots.

Given the board is a new replacement board, and the ram itself I know to work fine (and have also tried known good ram from another system) - the only common part is now the cpu. Either that or just very unlucky and received two duff motherboards.

 

Edit: Only other point of info I can think of to mention... The existence of the slots themselves is recognised. If I select 'Info'-->'More' from unraid, it lists all 8 slots (with A0 & A1 marked as DIMM_A1 & DIMM_A2), but nothing is seen in plugged into them.

Edited by extrobe
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Just in case anyone else is following/interested...

 

Despite having a new board, different ram, removing all additional hardware, I was still having issues.

I've now even installed a different CPU - a Xeon e5-2658v3 (es) - but this is even worse, with more slots unrecognised- though it does vary depending on what slot configuration I use. (Eg, if I put a stick in a0/A1, then not only would a0/a1 not register, but that seemed to disable other slots too,)

 

This got me thinking - assuming it's not another faulty board, everything has been swapped with another part, and the issue has remained.

 

The only constant through this is that I've been using non-ecc ram with the Xeon processor. My understanding is that this should not be an issue, but the mobo manual does state use non-ecc for i7 & ecc for e5.

So I've ordered a single 4gb of ecc ram to see if it shows up in the slot.

 

I'll report back once I've tried it, but is it plausible that the mobo won't play nicely with non-ecc ram paired with an e5 processor?

1495972013202804872953.jpg

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Could someone perhaps help me understand this bit too? (Top bullet point).  Is it suggesting I'm better off using the same size dimms within the same channel?

 

I have 4x4gb + 2x8gb

Should I aim to ensure I have matching size in say b0+b1 etc?

1495973053958448868112.jpg

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Thanks Kevin

 

D1 has been ok, but the single Dimm I've bought is really just as a test. If it works in all slots, then I'll replace all the non-ECC with ECC.

 

If I still have issues, I'll have to reach out to asus, as not sure what else I can try.

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No, I do have problems, that's my point. A0 + A1 are not being recognized, regardless of what config I use. Following the recommended layout for slots does not help. (If I only had 1 dimm, then sure, I'd be fine - but I have 6, and want to have 8).

 

The 1 dimm ECC I've bought is merely for troubleshooting. Whilst there is indeed a recommended slot, it should work in any slot. Of course, ideally I'd buy 6/8 ECC sticks, but I have to draw the line somewhere ;)

Edited by extrobe
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