Ram not fully detected

Nocturne_sa · 6 May 2015 at 22:00

Hi

I have an Asus P6x58D-E which was originally running 6 GB of Corsair XMS3 DD3 12800C9 1600MHZ 3*2). I've installed 3 more sticks of exactly the same ram. My computer originally showed 12GB so did CPU-Z. Restarted PC and now my computer/system only shows 8GB (CPU-Z still shows 12). What gives? I'm running Win & home premium so 12Gb shouldn't be an issue.

Any thoughts?

Cheers

OracIe · 7 May 2015 at 08:04

Have you stolen some for graphics or do you have a dedicated GFX card?

ZXSpectrum · 7 May 2015 at 08:46

That chipset is an utter nightmare. Its VERY finiky on ram and how much is put in it. Do you see RAM 12Gb (Useable 8.0Gb)?

I know that there are BIOS updates that add compatibility for memory constantly but I have seen it not fix this issue. You could also check that the memory isn't set to AUTO and bump the voltage on the QPI to see if that helps.

Oh and I have mainly found it with Corsair memory. Kingston seems to work fine.

wazza300 · 7 May 2015 at 11:50

swap the sticks around,also makesure your cpu cooler isn't too tight

it should work fine

Plec · 7 May 2015 at 12:14

wazza300 said:
make sure your cpu cooler isn't too tight

The above is easily overlooked - especially if you have a big cooler attached, or one that grips your socket like a vice - as it's very easy to warp the MB just where the memory slots sit.

If you've got a case that hasn't used all the motherboard hole fixings it's easy to get a slight warp with rigidly fitted heatsinks - and this can easily cause memory issues.

Nocturne_sa · 7 May 2015 at 15:52

Plec said:
The above is easily overlooked - especially if you have a big cooler attached, or one that grips your socket like a vice - as it's very easy to warp the MB just where the memory slots sit.

If you've got a case that hasn't used all the motherboard hole fixings it's easy to get a slight warp with rigidly fitted heatsinks - and this can easily cause memory issues.

I think this is it. The cooler is one that grips the socket and was making strange noises earlier and is sitting right at the top of the RAM.

I re-adjusted the fan so it stops making the stuttering noise and restarted the PC and its now showing 12GB. Bit of a n00b question but why is the cpu cooler causing memory errors?

Plec · 7 May 2015 at 16:23

In some instances the cooler can cause so much tension on the board (especially if the board isn't fully attached by all the motherboard riser fixings) that it can slightly warp the board. It just so happens that the memory slots are directly around this area and can then make the slots slightly unpredictable as the memory may not make a proper connection within the socket due to the slightly warped slot.

It's a more and more common problem with tight fixing and large coolers.

Nocturne_sa · 8 May 2015 at 10:32

Plec said:
In some instances the cooler can cause so much tension on the board (especially if the board isn't fully attached by all the motherboard riser fixings) that it can slightly warp the board. It just so happens that the memory slots are directly around this area and can then make the slots slightly unpredictable as the memory may not make a proper connection within the socket due to the slightly warped slot.

It's a more and more common problem with tight fixing and large coolers.

cheers

This seems to be an intermittent issue, had the same problem again last night. So switched the memory sticks and now the best I get is 10GB as opposed to 12GB. It only shows 10gb in the BIOS/system not 12GB with 10 available (CPU-Z is showing the correct 12GB).

Have readjusted the CPU cooler fan and can't think really think of anything else. Could the RAM be faulty?

wazza300 · 8 May 2015 at 10:47

The memory controller is integrated into the CPU,I think the bending of the board cuts the signal off in the copper traces from CPU to memory banks

Is it Intel pushpin cooler or one with a backplate? One with a backplate are better

Nocturne_sa · 8 May 2015 at 10:53

wazza300 said:
The memory controller is integrated into the CPU,I think the bending of the board cuts the signal off in the copper traces from CPU to memory banks

Is it Intel pushpin cooler or one with a backplate? One with a backplate are better

Its a Prolimatech Megahalems Rev B cooler with a sharkoon Silent Eagle 2000 Fan

cheers

kaku · 8 May 2015 at 19:04

I had this issue with some Corsair RAM; I ended up just RMA'ing it because it felt like I tried everything. The new RAM ended up working okay, but I have no idea why it would just suddenly drop like that.