8GB DDR3 modules on a Q45 intel chipset

[joshfourie]

HI,

I have the following

Manufacturer: Dell Optiplex 780
Model: 0C27VV A01
Chipset: Intel Q45/Q43 Rev 3
Southbridge: Intel 82801JB Rev 2

BIOS Version: A15
Date 08/06/2013

I already know I am unable to overclock on this motherboard 🙁 and therefore also unable to change anything w.r.t. memory.

I have the following issue. I have one 8GB and one 4GB 1600Mhz DDR3 module. Both these modules do not work on my motherboard as it just makes beeping noises. I would love to get this to work though. I have reset the BIOS many times and updated the BIOS to latest version I could find. Not sure if each DIMM slot has a maximum capacity though which would explain my current problem. It also does not seem to be very clear in the manual about this.

I hope someone out there can help

 

[SystemeInternational]

That Dell doesn't support 1600 MHz. Here is a quete I found on its manual:

"This system supports both 1066MHz and 1333MHz DDR3 memory, however the memory will operate at
1066MHz speed due to chipset specifications."

It's pretty easy to google the manual. The link for the manual is:
http://i.dell.com/sites/content/business/solutions/engineering-docs/en/Documents/optiplex-780-tech-guide.pdf

 

[Kisianik]

Unfortunately, if RAM doesn't work, it doesn't work (you already done everything). Question is why?

According to manual and this post only 1366MHz or 1066MHz RAM will work for sure, 8GB stick would not work, because Dell only allowed 2 GB sticks, and later acknowledged that 4GB stick are OK, nothing mentioned about 8 GB sticks.

 

[SystemeInternational]

Not precisely. You should be able to run 4 and 8 GB stick, BUT with the right frequency: 1066 and 1366 MHz. All higher memories scale down to ~3.5-3.7 GB when run on a 32 system: 32-bit CPU & 32-bit OS.
Thing is, you can actually underclock stuff from within the BIOS (change freq from 1600 to 1366 for insance), but then again the system must boot up normally first, which it doesn't with too much frequency

 

[capt_taco]

If it's a 32-bit operating system, 4GB is the limit of addressable memory anyway, so there'd be no point to an 8GB stick, or to two 4GB sticks.

 

[Kisianik]

Not precisely. You should be able to run 4 and 8 GB stick, BUT with the right frequency: 1066 and 1366 MHz. All higher memories scale down to ~3.5-3.7 GB when run on a 32 system: 32-bit CPU & 32-bit OS.
Thing is, you can actually underclock stuff from within the BIOS (change freq from 1600 to 1366 for insance), but then again the system must boot up normally first, which it doesn't with too much frequency

Dell BIOS is locked on all models except Alienware, so second part is not going to work.

For the first part read this, it is about high DENSITY RAM, which could be the case here.
http://en.community.dell.com/support-forums/desktop/f/3514/t/19610973
http://en.community.dell.com/support-forums/desktop/f/3514/p/19629648/20757310#20757310

Plus there is a limit of RAM in BIOS, it is not updated to today standards, so if BIOS say no, nothing you can do about it.

 

[Vic 40]

Googled the motherboard and every spec sheet i read states that only 1gb or 2gb modules will work with a max capacity of 8gb for total.Means that the 4gb nor the 8gb sticks are compatibel.

 

[Kisianik]

Googled the motherboard and every spec sheet i read states that only 1gb or 2gb modules will work with a max capacity of 8gb for total.Means that the 4gb nor the 8gb sticks are compatibel.

It was probably a quick search, I did a bit longer search http://www.dell-repasovane.cz/Optiplex_780_EN.pdf

I wish it was so easy.

 

[Tradesman1]

Your mobo and chipset, support 1 or 2 GB DRAM - another problem is most DRAM today is made with high density memory ICs which are not supported by the chipset, I'd look for GSkill Value NT series or their original Ripjaws (not the X or Z line) that are made with low density memory ICs and prob in 1066 to be on the safe side

 

[Kisianik]

another problem is most DRAM today is made with high density memory ICs which are not supported by the chipset, I'd look for GSkill Value NT series or their original Ripjaws (not the X or Z line) that are made with low density memory ICs and prob in 1066 to be on the safe side

This is the problem.

 

[Vic 40]

He hasn't told us what ram he has so how can you be sure of that?

 

[Kisianik]

joshfourie come back and talk to us, it is useless guessing this or that. Most likely you have newer HIGH DENSITY RAM, that is why 4 GB stick is not working, 8GB stick would not work at all, even low DENSITY, if it even exists.

In the other post OP stated that he has

Running 2 x 1 GB 1333Mhz DDR3 DIMM modules according to CPU-Z and 2 x 1GB 1066Mhz DDR3 DIMM modules according to the BIOS. A little confused

 

[joshfourie]

I seem to have received the solution but I will check. 2 x 4GB DDR3 1066Mhz modules should work as this is a Q45 board with 4 slots. As the manual states, 4 slot motherboard allows up to 16GB, which means 4GB per slot. Should work fine.

thanks for all the advise

 

[Vic 40]

It's up to you,but look at these as adviced by Tradesman1,
http://www.gskill.com/en/finder?cat=31&prop_2=0&prop_6=Dual+Channel+Kit&prop_3=0&prop_4=0&series=606&prop_14=DDR3

 

[Kisianik]

OK. Lets finish this thread once and for all.

I found 4GB sticks which reported compatible to Optiplex 780 with latest BIOS. Dell OptiPlex 780 System BIOS A15
After BIOS upgrade BIOS will be reset, so you need to put it back to AHCI auto detect.

Crucial 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10600) Desktop Memory Model (CT2KIT51264BA1339)

eigervue said:
Now it is running with A15 Bios on: 2x4gb Crucial ct2kit51264ba1339 -- This is no longer available on their site and is possibly discontinued but I got it new w/ lifetime warranty on amazon for 84 shipped with tax, and its on newegg too for 90.