1/2 32gb RAM not showing up: Asus 990FX Sabertooth + 4x8gb G.Skill RAM

[jnthodge]

I have:

- Asus 990FX Sabertooth motherboard
- AMD FX-8120 8-core CPU 3.1Ghz, not overclocked
- 4x8GB G.Skill DDR3 1333 PC3-10600/10666 CL9-9-9-24 1.5V

The individual sticks show up in the UFI Bios, but only 16Gb is exposed to the OS.

Does anyone know if I have to enable the even-numbered banks somehow, or change voltage or something to cause the BIOS to expose all 4 DIMMS to the OS?

I am doing heavy virtualization for home/experimentation work.

Thanks!

[Tradesman]

What version of Win64 are you running? Need Professional, Enterprise or Ultimate for more than 16GB. Home Premium is limited to 16GB, Home Basic to 8GB and Starter to 2GB

[jnthodge]

VMware Hyper-V ESXi

I am actually running VMWare's Hyper-V ESXi. It is a virtualization platform.

A few things to know:

- Any combination of the RAM chips works, so they're all good.
- The individual RAM chips show up in the "banks" section of my ASUS UEFI BIOS as 8192 Megs. So the motherboard sees them and recognizes them as 8Gb DRAMs.
- The Summary of the system in the UEFI BIOS before any OS loads, reports only 16Gb of RAM, even though 32 is installed
- The Motherboard specifications report that 32Gb is supported.
- I am running all RAM settings at "Auto"

Hopefully this helps.

Jason

And, by the way, I am running Windows 2008 Enterprise, and MintLinux so far (at the same time, I love virtualization!!)

[Tradesman]

If the BIOS sees all, would guess it's something w/ Hyper-V ESXi, maybe a toggle or something, haven't really used it, but believe even the free version supports up to 32GB if I remember right

[jnthodge]

You are correct about the 32Gb. But even before the OS starts loading, the UEFI BIOS says it has only 16Gb, while simultaneously saying 4 x 8192MB in the 4 DRAM Banks. I tried trouble shooting this before I installed any hard drive or OS, but to no avail.

Are there any custom timings/voltages or something I should be targetting? I cranked up the DRAM voltage to 1.65 from the stock 1.5 to see if it would help, but no mas.

Thoughts, suggestions?

Thanks,

Jason

[damric]

- The Summary of the system in the UEFI BIOS before any OS loads, reports only 16Gb of RAM, even though 32 is installed

I would take the issue to ASUS. They only have one 8GB stick on the qvl for that board, but they claim compatibility up to 32GB.

It might be that they had to run it slow, like at DDR3-1066 to get it to work. I would ask them exactly what settings that they had success with 32GB or if the marketing team is just full of it.

You could try all sticks at DDR3-1066 9-9-9-30 and see if it works, then speed it up from there.

[Tradesman]

I'm not overly familar with that mobo, but if only showing 16GB in the BIOS while identifying all the sticks correctly, it too may have a toggle or something in the BIOS to allow for more than 16GB of DRAM. To that end I'd agree w/ Damric and take it to Asus...I know I'd love to here what they say, that's one reason I brought up the OS and it's limitations, I've had the opportunity to deal with their support a couple of times where they didn't know about the various versions limitations

[damric]

Makes me wonder if ASUS even loaded up an OS, or if they just booted to the BIOS menu when they tested it. I'd fully expect a very dodgy answer.

[Tradesman]

That would be my thought

[GSKILL TECH]

Should not be a problem with the motheboard/CPU/memory combo, we test them to be perfectly fine.

Did you purchase a 32GB kit or individual modules? Did you make sure the modules are firmly installed? Have you tried moving them around in different slots?

Thank you
GSKILL TECH