[Solved] 24GB of RAM - Only 5.5GB usable in Windows [Mobo: UD5-X58 Rev 1.0]

[Vice]

I have a Core i7 920 & Gigabyte UD5-X58 Motherboard and I've just purchased 24GB of Mushkin memory to upgrade from my 6GB of Corsair Memory. My operating system is Windows Server 2008 R2 (Which is a 64-bit Operating System)

I am having an issue where only 5.5GB is being detected by the system. I have two Highpoint 2320 RAID Cards and I think they are each reserving 256MB of that memory (taking it from 6GB to 5.5GB even when I had 6GB of Memory installed) but with 24GB installed I am still only able to use 5.5GB instead of 23.5GB which is what I expected.

The BIOS detects all 24GB, as does Windows itself, specifically Windows says 24GB (5.5GB usable) and in Task Manager it also reads only 5629MB next to 'Total' for the memory amount.

So far I have tried the following steps and none of these have changed the system from reporting 5.5GB:
Removing 1 Dimm from Slot 6
Swapping 2 Dimms around
Increasing VTT voltage to 1.35v
Increasing Memory voltage from 1.5v (recommended) to 1.6v
Clearing CMOS and running 'vanilla'

The most confusing part of this is that to me it should be reporting at-least 8GB or 7.5GB since all my ram is 4GB modules, instead it is reporting 5.5GB which is one full module (4GB) and half of another module (2GB) - How is this even possible?

I've done a lot of Googling and this does seem to be a common issue on x58 boards but I have previously been able to get this board to detect 10GB of memory when I used it for my desktop system instead of as a server system so I know it is technically able to detect more memory but it appears Windows Server 2008 R2 does not want to address it.

I really need some help here, and before anyone asks why I need 24GB of memory this is being used for a Server with a lot of VM's not for playing Crysis  

[Dark Mantis]

Hi and welcome to the Gigabyte Forum.

I really need some help here, and before anyone asks why I need 24GB of memory this is being used for a Server with a lot of VM's not for playing Crysis   

Oh well if it isn't for anything really important then................

You don't say exactly what Mushkin memory you have so I can't be specific.

Your memory voltages seem to be low considering the fact that you have filled all the banks of RAM. I would normally expect to be nearer 1.4v and 1.70v
Your uncore could be too high or low also which could make the memory controller not work correctly.

[Vice]

Hi and welcome to the Gigabyte Forum.

I really need some help here, and before anyone asks why I need 24GB of memory this is being used for a Server with a lot of VM's not for playing Crysis   

Oh well if it isn't for anything really important then................

You don't say exactly what Mushkin memory you have so I can't be specific.

Your memory voltages seem to be low considering the fact that you have filled all the banks of RAM. I would normally expect to be nearer 1.4v and 1.70v
Your uncore could be too high or low also which could make the memory controller not work correctly.

The memory is Mushkin 998770 aka http://www.mushkin.com/Memory/Silverline/998770.aspx

They are rated for 1333MHz @ CAS 9 with Voltage 1.5 - I have tried the memory at 1.6v I have tried loosening the timings and I have also tried running it at 1066MHz - Nothing had an affect unfortunately.

Thank you for reading my post I am grateful, also thank you for the warm welcome

[Vice]

To anyone reading this via Google I managed to fix this problem with the help of Mushkin (Their support is excellent btw!) the issue turned out to be the MSConfig maximum memory setting. It was set to 2048, once I set it to 24GB I could address all the memory.

I hope someone finds this useful

[Dark Mantis]

Glad you managed to sort it out but what I don't understand is why it was set to 2048 anyway. But thanks for the heads up anyway it might be usefull in the future. Have a nice Christmas.