8GB RAM But 3.96GB Usable?

[ihsaan96]

Hey guys , I've got two sticks of Patriot Black Mamba DDR3 Ram at 4GB each and recently it shows that I've only got 3.96GB Usable and shows Single Channel Memory Mode In The Bios? Both sticks are picked up and shown but it only shows 4GB usable and single channel rather than dual channel.

I've reseated them numerous times and swapped slots and they're in correct dual channel slots , I've unchecked max memory in that Advanced Boot settings and checked in BIOS and put in XMP 1.3 profile but no solutions...What to do?

Thanks

 

[noidea_77]

One of the sticks is faulty. Bios only recognizes the spd chip, but the can not write/read the memory cells.

 

[neieus]

I can only imagine the RAM or the slot being bad. Have you checked the BIOS revisions to see if it maybe a known issue?

 

[ihsaan96]

Have no idea why the stick would be faulty & how would I check the BIOS revisions?

Thanks

 

[ihsaan96]

This also shows in my Resource Monitor. It shows 4139mb reserved for hardware?!

 

[ihsaan96]

Also for some reason when only one stick of ram is inserted , it shows Hardware Reserved as about 40mb , when using either sticks single. But when both sticks are inserted it shows 4139mb ? This is confusing!

 

[arweth]

I had a similar problem with a system before. You need to check your maximum memory limit on your motherboard. I had one that saw all the RAM I put into it but was only able to physically use so much of it. You just need to check you are using an amount that is within the total limit and within the limit per slot.

 

[johnlee04009]

What about running a diag.?
Bios may find some errors in one DIMM and drop it.

 

[getochkn]

What motherboard?

 

[Uberragen21]

You're overlooking the simplest check. You have 2 sticks of memory and to rule out one stick as defective, simply remove one. Boot the system with the memory in the slot 1 and test. If it doesn't boot, reseat the memory and make sure it's seated fully. If still it doesn't work, then it's defective.

If both memory modules check out okay when testing one at a time, then it might be the way Windows 8 reads and displays the memory. If you ever dealt with Vista, it had a similar issue. Vista would show your full memory, but would show it ALL in use. Don't forget Windows 8 is the illegitimate step-child of Vista.

 

[ihsaan96]

I've run Memtest over night and came out with 8 passes. I've used one stick at a time and reseated etc and PC boots up fine and ran both sticks in the A channel & B channel incase it was the dimm slots. No success so I'm guessing it's got to do with Windows 8?

 

[ihsaan96]

And my motherboard is the AsRock 990FX Extreme3

 

[Uberragen21]

I've run Memtest over night and came out with 8 passes. I've used one stick at a time and reseated etc and PC boots up fine and ran both sticks in the A channel & B channel incase it was the dimm slots. No success so I'm guessing it's got to do with Windows 8?

If both sticks run fine, your memory is fine. I also doubt your motherboard is to blame. I'm willing to bet it's Windows 8. I've only had limited exposure to Windows 8 through work, so I can't say for certain.

Have you tried CPU-z to analyze the memory?

 

[ihsaan96]

Yes I've tried CPU-Z and it shows up fine as in all the settings etc. But would Windows 8 make my PC show the ram as single channel mode in the bios?

 

[getochkn]

I have a 4GB, 2GB, 1GB, 1GB stick on my PC on a Dell board and I have 1MB for hardware reserved. I would google the problem and see if others have had issues, maybe with that particular board.

 

[longshanks2]

Hi Folks , I went through most of this at least twice trying to fix my pc ram 8GB installed 3.96 usable , you are going to curse of laugh but I managed to solve this by cleaning the cpu which had got thermal compound on the edge pins causing a short . Alcohol and a very soft brush plus patience . 8GB ram now all usable . It was only a very small amount but contained silver tins which conducted . Job done !