Question [SOLVED] Bios and windows 10 only detects 16GB of the 32GB but CPU-Z detects all 32GB RAM

[ropeccool]

Bios and windows 10 only detects 16GB of the 32GB but CPU-Z detects all 32GB of RAM. The bios knows there is four sticks of eight individually but it says that the total memory installed is 16gb. When I had a look at the task manager, it also only said I'm using two of the four available slots. I'm not sure what's going on here. Can anyone help?

Motherboard: MSI B150 PC MATE
CPU: I7 7700
RAM: CORSAIR 4x8 DDR4 2666mhz
GPU: Asus GTX 1080

SOLUTION: Dont mix ram because it has a high probability of not working. Even if they are the same brand and have the same mhz you should still make sure the model numbers are EXACTLY the same. Make sure to purchase 4 of the exact same set.

 

[Colif]

are all 4 from the same set?

Try running memtest86 on each of your ram sticks, one stick at a time, up to 4 passes. Only error count you want is 0, any higher could be cause of the problem. Remove/replace ram sticks with errors. Memtest is created as a bootable USB so that you don’t need windows to run it

 

[Deleted member 2947362]

You did remember to turn off the PSU or unplug the computer from the mains supply before you installed your ram didn't you?

If the ram was already installed and had been working correctly before this issue came to light that is a strange one?

I would unplug the PC from mains supply remove all the ram modules give the gold connecters a light clean with something like a magic eraser but doesn't have to be that exactly just make sure they are clean.

install ram pushing firmly making sure they are fully seated and test again see if that has resolved the issue.

If its still doing the same there maybe a chance one or some of the IC's are faulty you would have to test each stick individually or if you just bought it then might just be faulty out of the box.

 

[DRagor]

I'm not sure what's going on here.

That is quite simple. BIOS can detect all 4 sticks but is unable to properly communicate with two of them so it just disables them. That's what Windows sees (CPU-Z can read same data as BIOS). This can be caused by either problem with sticks or slots. First thing to do is check each stick alone if it boots and gives 8GB. If all pass then pick one stick and check each slot separately. Hopefully you get a fail somewhere before you end this procedure because otherwise things will get tricky.

 

[Deleted member 2947362]

That is quite simple. BIOS can detect all 4 sticks but is unable to properly communicate with two of them so it just disables them. That's what Windows sees (CPU-Z can read same data as BIOS). This can be caused by either problem with sticks or slots. First thing to do is check each stick alone if it boots and gives 8GB. If all pass then pick one stick and check each slot separately. Hopefully you get a fail somewhere before you end this procedure because otherwise things will get tricky.

hopefully they just need reseating lol

Testing for faulty ram modules is a pain in a** and can send you down all kind of rabbit holes

I had a build years ago that was a real pain trying to keep ram stable after sending several kits back and suffering a bad case of Ram Rage, it turned out it was an issue with the type of graphics card and a certain chipset combo lol

I cant remember the motherboard but I do remember it had 2 X HD4870 in crossfire. (sozz OP I don't want to take focus off your problem just wanted to slip that in lol)

 

[ropeccool]

That is quite simple. BIOS can detect all 4 sticks but is unable to properly communicate with two of them so it just disables them. That's what Windows sees (CPU-Z can read same data as BIOS). This can be caused by either problem with sticks or slots. First thing to do is check each stick alone if it boots and gives 8GB. If all pass then pick one stick and check each slot separately. Hopefully you get a fail somewhere before you end this procedure because otherwise things will get tricky.

Ok, I tested all the ram by testing each stick in each slot individually which meant I did 16 different combinations. They all worked fine and were recognised. It seems to be that individually they all work fine and there are no hardware issues with the motherboard or the ram but collectively windows still wont recognise all 32GB (except CPU-Z). However, ive discovered that , by default, 2 of the sticks run at 2133mhz and 2 run at 2400mhz. This is very strange because all 4 sticks say they run up to 2666mhz. Also, the ram is all corsair and model numbers are different but I really didnt think that would matter. Here are the pics of my ram:

https://imgur.com/a/zOzAlX3

View: https://imgur.com/a/zOzAlX3

 

[ropeccool]

are all 4 from the same set?

Try running memtest86 on each of your ram sticks, one stick at a time, up to 4 passes. Only error count you want is 0, any higher could be cause of the problem. Remove/replace ram sticks with errors. Memtest is created as a bootable USB so that you don’t need windows to run it

It only recognised two of the sticks but I did the test anyways and there were no errors. I tested all the ram by testing each stick in each slot individually which meant I did 16 different combinations. They all worked fine and were recognised but collectively windows still wont recognise all 32GB (except CPU-Z). Also, they are not all from the same set, I attached photos in a reply to another member

 

[DRagor]

Also, the ram is all corsair and model numbers are different but I really didnt think that would matter.

So you are mixing 2 kits, with most likely different JEDEC settings at that. And surprised it does not work?
Enable XMP at BIOS and see if that helps.

 

[ropeccool]

So you are mixing 2 kits, with most likely different JEDEC settings at that. And surprised it does not work?
Enable XMP at BIOS and see if that helps.

Enabling XMP did not work unfortunately. It still only sees 16GB. Would it be better for me to just return these sticks and buy all 4 of the exact same ram?

 

[DRagor]

Enabling XMP did not work unfortunately. It still only sees 16GB. Would it be better for me to just return these sticks and buy all 4 of the exact same ram?

Assuming the problem does not lie in motherboard (you did not done second part of the testing I described) then yes - but don't buy 4 "of same RAM", buy 4 stick kit. Otherwise same problem may happen. Or better yet buy 2x16 kit.