Linux not seeing Ram. But Windows does ?

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Guys am building a wee home server out of random parts. And was looking to try Linux as I am not confident with it.

Xeon E5-2650 v4
Board is Machinist X99 PR9-H (from A Express)
128GB 4*32GB (Matching sticks)

So everything looks ok in bios and all ram is seen. When I installed Ubuntu it only showed 64GB installed. Same on debian when I tried

When I installed windows server straight away it picked up the correct amount of Ram. 128GB

Anyone any ideas?

Regards
 
What does "free -m" and "cat proc/mem" show in Linux? Would be helpful to get a "dmesg" too - you tried reseating the modules? I know they work in Windows, but worth a try. Also might be worth trying each slot one by one in Linux. I'd also run memtest. Are they running ECC or anything?
 
Did you install 32bit OS instead of 64 bit? IIRC both Debian and Ubuntu cap at 64GB in 32bit mode.

I considered this, but as they mentioned Ubuntu, I don't think Ubuntu even offer a 32-bit release these days - not to say you can't download an older copy of course.

I may be wrong*
 
I considered this, but as they mentioned Ubuntu, I don't think Ubuntu even offer a 32-bit release these days - not to say you can't download an older copy of course.

I may be wrong*

Haven't paid much attention when installing it in awhile so not sure off the top of my head.
 
So memtest ran for 8 hours and all passed.

I tried ubuntu server this morning and it sees all the ram. (I was looking normal ubuntu since it has a gui) but I might have to stick with ubuntu server.

The ubuntu image i was using was ubuntu 24.04.03 desktop - amd 64

So yep im confused lol
 
So memtest ran for 8 hours and all passed.

I tried ubuntu server this morning and it sees all the ram. (I was looking normal ubuntu since it has a gui) but I might have to stick with ubuntu server.

The ubuntu image i was using was ubuntu 24.04.03 desktop - amd 64

So yep im confused lol
Do the Ubuntu settings say you have the 64bit version installed?
 
Weird one, maybe the desktop is reserving a large chunk of RAM for some reason. As mentioned already dmesg may give you a hint. ( dmesg | grep -i reserved, dmesg | grep -i memory etc )

Server option is probably your best choice for the home server anyway, less crap.
 
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