No POST after adding 2*32GB DDR5 with XMP

[Dirt Chip]

As a fallow up to my last thread on the matter, I purchase a new set of identical memory - Corsair Vengeance 2*32GB DDR5 5200Mhz C40 (CMK64GX5M2B5200C40).
Now I have 4*32GB.
Prior to installation I turned off XMP - there is only one profile option is available to this modal @5200Mhz - and set it to the default JEDAC 4800Mhz.
I installed the new 2*32GB and the system POST correctly, recognizing all 128GB.
Then I turned on XMP to the 5200Mhz profile, reset and from that point - no POST. Tried reset, turn off-on and let it think for itself for 15 min but for no good.
The DRAM LED on the mobo is solid red as an error indicator.
All other setting beside XMP, regarding memory, are on default.

Any Idea how to make it work with this very modest "XMP OC"?

 

[ir_cow]

Not surprised. 4x dual rank at 5200 is a tall order. Probably need to drop It to 4800 if not lower.

 

[TumbleGeorge]

From webpage of motherboard:

Memory

1. Support for DDR5 6000(O.C.) / 5800(O.C.) / 5600(O.C.) / 5400(O.C.) / 5200(O.C.) / 4800 / 4000 MT/s memory modules

5200 is OC for this motherboard. Try on 4800 for first boot then try to set higher frequencies if you want.

 

[ir_cow]

I'm guessing you don't want to deal with manually setting CPU related voltages right?

It has been a while, but I do remember having a hard time getting 128GB 5200 to post...or was it 5600. Either way I have to manually set my voltages that the motherboard didn't do it well enough for stability / booting.

Whatever you settle on make sure to run some memory stability tests since this is a work computer. Don't want corrupted data.

 

[Dirt Chip]

I'm guessing you don't want to deal with manually setting CPU related voltages right?

It has been a while, but I do remember having a hard time getting 128GB 5200 to post...or was it 5600. Either way I have to manually set my voltages that the motherboard didn't do it well enough for stability / booting.

Whatever you settle on make sure to run some memory stability tests since this is a work computer. Don't want corrupted data.

If it's more than a 1-2 settings to tune with ease, than no. If it's complicated I will settle on 4800.

What memory stability test do you recommend?

Maybe bios update can help to get 5200?

 

[Shrek]

I'd try the BIOS update

 

[eidairaman1]

How do you know the ics are exactly the same on those ram?

 

[ir_cow]

How do you know the ics are exactly the same on those ram?

Lucky Corsair has a Rev number on each set. It is entirely possible they are different though. 5200 can be Micron, Samsung or Hynix and multiple revisions of micron and Hynix over the last year. Check the number on the DIMM barcode.

 

[bug]

Not helpful post, but your motherboard is crap. Motherboards these days have the ability to go back to prior working settings on their own when the boot process gets messed up.

Fwiw, the official web site says the motherboard only supports up to two of those modules: https://www.gigabyte.com/Motherboard/Z690-AERO-G-rev-1x/support#support-memsup

 

[ir_cow]

Not helpful post, but your motherboard is crap. Motherboards these days have the ability to go back to prior working settings on their own when the boot process gets messed up.

Not a crap motherboard and what you are talking about is booting into BIOS safe mode after failed overclock. This one does it as well. That MB certainly isn't going to be reaching super high memory clocks, but it is still decent enough. Basically a Elite AX with a few extra features.

 

[bug]

Not a crap motherboard and what you are talking about is booting into BIOS safe mode after failed overclock. This one does it as well. That MB certainly isn't going to be reaching super high memory clocks, but it is still decent enough. Basically a Elite AX with a few extra features.

That's not what I'm talking about. My last two motherboards would revert to standard JEDEC timings when I pushed the memory too far.

 

[ir_cow]

That's not what I'm talking about. My last two motherboards would revert to standard JEDEC timings when I pushed the memory too far.

Yes that is what happens when the safety kicks in from a failed boot.

 

[eidairaman1]

Yes that is what happens when the safety kicks in from a failed boot.

Heck i believe even my 990fx board has it

 

[bug]

Heck i believe even my 990fx board has it

Well, the OP said:

Then I turned on XMP to the 5200Mhz profile, reset and from that point - no POST. Tried reset, turn off-on and let it think for itself for 15 min but for no good.

So it seems that's not what he's seeing.

 

[ir_cow]

So it seems that's not what he's seeing.

Doesn't mean it always works. I bet the next time it was powered on it came up with the failed boot BIOS screen

Anyways the Op is looking for solutions, not some people saying the MB sucks. So assume it is indeed the exact some ICs for both kits, basically without manually dicking with CPU voltages, it seems 4800 is the limit. It is four dual-rank DIMMS. 2x dual rank tops out at 6800~, add two more and it goes way down.

 

[eidairaman1]

Doesn't mean it always works. I bet the next time it was powered on it came up with the failed boot BIOS screen

Anyways the Op is looking for solutions, not some people saying the MB sucks. So assume it is indeed the exact some ICs for both kits, basically without manually dicking with CPU voltages, it seems 4800 is the limit. It is four dual-rank DIMMS. 2x dual rank tops out at 6800~, add two more and it goes way down.

I do remember that function doing that after some overclocking situations.

 

[Dirt Chip]

Fallow up: I removed the 2 new DIMM`s just to get into POST and turend off XMP, re-install the 2 new DIMM`s.
It POST, just as in the first time.
In the bios I see the the current memory fequency is 4000MHz although the bios set to JEDAC 4800MHz. I guess it was the same in the first attemp but I didnt notice it.
When I atemmpted to menualy set it to 4800MHz (insted of "auto") it didnt POST.
Anyway, all the DIMM`s are from Micron and from the same version.
Also, it seems that 4800MHz automaticly downclock to 3600MHz if 32GB*4DIMM*2R are populated so I guess i`m "lucky"to achive 4000MHz...

If I have the time I will try to upgrade the bios to see if it can help to reach 4800MHz (maybe 4400MHz also possiable) but I doubt it will help.

 

[bug]

4000 is the fallback. You can definitely squeeze more than that, but how much, it depends on your luck. You'll have to fiddle with timings and voltage a bit, I hope you have the stomach for that. It's no fun.

 

[eidairaman1]

Fallow up: I removed the 2 new DIMM`s just to get into POST and turend off XMP, re-install the 2 new DIMM`s.
It POST, just as in the first time.
In the bios I see the the current memory fequency is 4000MHz although the bios set to JEDAC 4800MHz. I guess it was the same in the first attemp but I didnt notice it.
When I atemmpted to menualy set it to 4800MHz (insted of "auto") it didnt POST.
Anyway, all the DIMM`s are from Micron and from the same version.
Also, it seems that 4800MHz automaticly downclock to 3600MHz if 32GB*4DIMM*2R are populated so I guess i`m "lucky"to achive 4000MHz...

If I have the time I will try to upgrade the bios to see if it can help to reach 4800MHz (maybe 4400MHz also possiable) but I doubt it will help.

View attachment 300443

Yup thats the cpu/board limitation when 4 slots are occupied

 

[ir_cow]

Sorry to say but 4x dual-rank really isn't supported on 12/13th gen desktop. Not what you want to hear, but that is the reality.

To get to 4800 and above you will need to manually set the CPU SA, VDD2 and VDDQ_TX.

Level1 has a good video explaining why it's so hard to run so many ranks. effectively you are running 8 ranks of memory on a desktop CPU not designed for that.

If you think AMD Ryzen will be better, it's actually worse.

 

[chrcoluk]

Are all ddr5 dimms dual rank?

 

[Dirt Chip]

Yup thats the cpu/board limitation when 4 slots are occupied

Actually a very good reason to go 2*48GB if it's enough..

Sorry to say but 4x dual-rank really isn't supported on 12/13th gen desktop. Not what you want to hear, but that is the reality.

To get to 4800 and above you will need to manually set the CPU SA, VDD2 and VDDQ_TX.

Level1 has a good video explaining why it's so hard to run so many ranks. effectively you are running 8 ranks of memory on a desktop CPU not designed for that.

If you think AMD Ryzen will be better, it's actually worse.

Yeh, it's a bitch.
Anyway, that slow but abundant memory is much better than faster one that run out shortly.
I will live with that peacefully as long as it stays stable.

 

[ir_cow]

Haven't needed over 64GB for my video projects yet.

But when you do run out, things start to crash. The HEDT platform (Threadripper and Xeon) are a godsend for those who need a ton of memory.

If you need a piece of mind that your current speed is stable. Download Memtest5 and run it. By default it does 3 passes. Should take like an hour or more for that much memory.

 

[bug]

Haven't needed over 64GB for my video projects yet.

But when you do run out, things start to crash. The HEDT platform (Threadripper and Xeon) are a godsend for those who need a ton of memory.

If you need a piece of mind that your current speed is stable. Download Memtest5 and run it. By default it does 3 passes. Should take like an hour or more for that much memory.

I was gonna say, regardless of what manufacturers put on their boxes, when you need that much RAM, you're looking at a workstation CPU (and chipset).

 

[jxdking]

I am using 128GB@5600MT/s on AM5.
Not sure the situation on intel side.

The key is the memory bus termination values.
If you can find similar settings on intel, try
RttNomRd = 48 Ohm
RttNomWr = 48 Ohm

If that 128GB kit is on your mother board QVL list, 5200 should work.