GA-X79-UD3 (Rev 1.0) Wrong Ram Value Reported After Bios Update

[grimgriefer]

Hi folks,

First time using the Gigabyte forum and hoping or some advice. I''ve been using a GA-X79-UD3 (Rev 1.0) with an Intel 3930k and 32GB of Corsair CML16GX3M2A1600C10 (4 x 8GB Quad Channel RAM) for over a year without much of an issue. Recently I spotted an updated bios so decided to apply it to keep the board up to date but its caused me a weird issue that I haven't been able to resolve yet.

The bios pics show the F.16 bios because I reverted back to it to try and fix the issue without any luck. Anyway as you can see the total memory size is reported as 32GB under the MIT tab but only 28GB under the System Information tab. Windows only reports 28GB of useable ram yet CPU-Z says there should be 32GB available.

I've tried refreshing the system between the F.16 and F.20 bios and also removed and reseated the ram in different slots with no change. As I'm a heavy user of VM's for study purposes losing 4GB of ram is a bit of a problem for me so any help would be much appreciated.







F.20 Bios
http://www.gigabyte.com/products/product-page.aspx?pid=4050#bios

[Tiger]

CML16GX3M2A1600C10 is a 16GB dual channel kit, not a 32GB quad channel kit.

If you are combining multiple kits, I would advise you not to use XMP (eXtreme Memory Profile) as the settings are for two not four DIMMs. I would recommend you clear the CMOS to remedy the missing size. After clearing the CMOS, first Load Optimized Defaults from the BIOS 'Save and Exit Setup' menu, then make any custom changes that you may have.

Corsair says it is definitely possible that two kits would run together in the same system, there is a chance that you may need to reduce the speed of the memory due to motherboard chipset limitations when populating more than one memory module per channel on the board.  If you have problems mixing sets, it is suggested to manually lower the frequency of the memory.

I see the memory is already running at 1333MHz not 1600MHz. Do you recall buying two kits? I would try manually setting the memory clock and DRAM Timings.

I wouldn't expect two kits to work correctly together however there is a chance that they will. Do you have a link to where you bought the memory?

[grimgriefer]

CML16GX3M2A1600C10 is a 16GB dual channel kit, not a 32GB quad channel kit.

If you are combining multiple kits, I would advise you not to use XMP (eXtreme Memory Profile) as the settings are for two not four DIMMs. I would recommend you clear the CMOS to remedy the missing size. After clearing the CMOS, first Load Optimized Defaults from the BIOS 'Save and Exit Setup' menu, then make any custom changes that you may have.

Corsair says it is definitely possible that two kits would run together in the same system, there is a chance that you may need to reduce the speed of the memory due to motherboard chipset limitations when populating more than one memory module per channel on the board.  If you have problems mixing sets, it is suggested to manually lower the frequency of the memory.

I see the memory is already running at 1333MHz not 1600MHz. Do you recall buying two kits? I would try manually setting the memory clock and DRAM Timings.

I wouldn't expect two kits to work correctly together however there is a chance that they will. Do you have a link to where you bought the memory?

Thanks for taking the time to response Tiger. This is where I bought the memory from and from lookin into it a little more I can see your point about it not being quad channel. I had bought the kits separately, maybe due to the misleading title.

http://www.aria.co.uk/Products/Components/RAM/DDR3/Dual+Channel+1600MHz/16GB+%282x8GB%29+Corsair+Vengeance+Jet+Black+Low+Profile+1600MHz+CL10+DDR3+Dual%2FQuad+Channel+Kit+%5BCML16GX3M2A1600C10%5D+?productId=52474

The weird thing is that it has been running for a year and a half happily reporting and making available the 32GB of ram but updating to F.20 seems to have changed that. I wish I had taken a backup of the original bios I was using before updating now. I can't be certain but I thought my bios was prior to F.16 when it was working but I may be mistaken.