Question 24gb RAM showing in BIOS only 16gb usable (8gb reserve)

Dec 11, 2020
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I was running 16gb RAM, and decided to take an extra 8gb stick and add it to my PC for 24gb total. My system was running the 16gb fine, but when i add the extra 8gb it shows 24gb in my BIOS and when i get to Windows it shows that 8gb is reserved. Windows and my bios both see the 24gb, but i am seeing 8gb reserved.

I have checked online and scoured many sources, trying each step with no solution, other than removing the battery from my board and resetting it.

So, i confirmed that the new 8gb stick is compatible with my board on the QVL. This is the funny part. My new 8gb stick is on the list, but my 16gb are not. Weird?

In the end, i am wondering how my system is seeing the 24gb, is okay with all the RAM being there and can see them all, but still reserve 8gb?

asus 970 pro gaming
fx 8350
GTX 1060 6gb
8
16gb Patriot DDR3 1866
(trying to add 8gb Corsair DDR3 1600mhz)

I also tried to put the RAM in a different board and it had the same issue..... i have 3 mobos and none are liking this lol
 
I was running 16gb RAM, and decided to take an extra 8gb stick and add it to my PC for 24gb total. My system was running the 16gb fine, but when i add the extra 8gb it shows 24gb in my BIOS and when i get to Windows it shows that 8gb is reserved. Windows and my bios both see the 24gb, but i am seeing 8gb reserved.

I have checked online and scoured many sources, trying each step with no solution, other than removing the battery from my board and resetting it.

So, i confirmed that the new 8gb stick is compatible with my board on the QVL. This is the funny part. My new 8gb stick is on the list, but my 16gb are not. Weird?

In the end, i am wondering how my system is seeing the 24gb, is okay with all the RAM being there and can see them all, but still reserve 8gb?

asus 970 pro gaming
fx 8350
GTX 1060 6gb
8
16gb Patriot DDR3 1866
(trying to add 8gb Corsair DDR3 1600mhz)

I also tried to put the RAM in a different board and it had the same issue..... i have 3 mobos and none are liking this lol
The QVL is a point of reference.
Not all RAM models out there, that could work with that motherboard are tested, so there could be many modules compatible with your motherboard that did not make to the test bench.
That configuration is not recommended in your motherboard, check memory section on the manual.
That motherboard maps a RAM kit (pairs) in a Dual-Channel configuration and any extra single module is mapped as Single Channel.


It is not recommended to mix RAM modules that were not tested to work together, since it is hard to predict the outcome.
RAM models, besides been compatible with your motherboard, have to work in tandem.
When you mix and match stick that may have different Speed, CAS latency, timings, voltage, brand, etc...half of the times a computer might run just fine, but the
other times you might get errors or the motherboard might just refuses to work.
Motherboards, might automatically, underclock the faster RAM stick to match the other, so you wouldn't run into any issues.
Even when they appear to be similar, the IC chips might come from different manufactures.
To be sure that RAM will work together you will have to buy RAM kits.
That's why manufacturers and vendors won't provide support for that type of configuration.

I think your system will work better with a 16GB kit...more RAM does not automatically translate into better performance.
 
Last edited:
Dec 11, 2020
6
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Awesome thanks! I'm new to this forum and thread thing so sorry for the late reply! I've been sticking with the 16gb kit and just put the 8gb in my back up/kids PC. I appreciate the info!
 
Dec 11, 2020
6
0
10
The QVL is a point of reference.
Not all RAM models out there, that could work with that motherboard are tested, so there could be many modules compatible with your motherboard that did not make to the test bench.
That configuration is not recommended in your motherboard, check memory section on the manual.
That motherboard maps a RAM kit (pairs) in a Dual-Channel configuration and any extra single module is mapped as Single Channel.


It is not recommended to mix RAM modules that were not tested to work together, since it is hard to predict the outcome.
RAM models, besides been compatible with your motherboard, have to work in tandem.
When you mix and match stick that may have different Speed, CAS latency, timings, voltage, brand, etc...half of the times a computer might run just fine, but the
other times you might get errors or the motherboard might just refuses to work.
Motherboards, might automatically, underclock the faster RAM stick to match the other, so you wouldn't run into any issues.
Even when they appear to be similar, the IC chips might come from different manufactures.
To be sure that RAM will work together you will have to buy RAM kits.
That's why manufacturers and vendors won't provide support for that type of configuration.

I think your system will work better with a 16GB kit...more RAM does not automatically translate into better performance.
soooooo, after I finally figured out how to reply to you, i went and tried switching my RAM around... turns out I can install and use 16gb on slots 1-2 but when set as 1-3 it only lets me use 8gb and reserves the rest... i tried all combos of the RAM possible, and only 1-2 with the 16gb works.... weird? wondering if a cpl slots aren't working proper? I am going to attempt to try this with my 2nd PC and see what happens, will report back soon.
 
... turns out I can install and use 16gb on slots 1-2 but when set as 1-3 it only lets me use 8gb and reserves the rest... i tried all combos of the RAM possible, and only 1-2 with the 16gb works.... weird?
Is the Patriot 16GB RAM from a kit?
If you are installing a 16GB RAM from a 16GB (2x 8GB) kit , then it should be installed on RAM sockets A2 & B2 (2nd and 4th from CPU)


wondering if a cpl slots aren't working proper? I am going to attempt to try this with my 2nd PC and see what happens, will report back soon.
Motherboards have different specs and features, so a RAM configuration could work on a motherboard but it might not work on another and that does not imply something is broken.
Follow the motherboard manual.
 
Dec 11, 2020
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Is the Patriot 16GB RAM from a kit?
If you are installing a 16GB RAM from a 16GB (2x 8GB) kit , then it should be installed on RAM sockets A2 & B2 (2nd and 4th from CPU)



Motherboards have different specs and features, so a RAM configuration could work on a motherboard but it might not work on another and that does not imply something is broken.
Follow the motherboard manual.
Ya I have tried them on slots A2 and B2 , seems that only a1 and a2 are working together with the 16gb kit that I am using. Weird part is that if I follow the manual, and install a2 b2 or even a1 b1, it reserves half of it and only shows 8 GB usable. If I install a1 and a2, all 16 shows up and is usable? I find it very puzzling.

I have been using the 16gb kit in slots a1 and a2 for a while now and it seems to work fine. Added a strix 1080 to my rig and it works np, and shares memory with my RAM hence me wanting to add another 8gb to my system. Kind of give it to my GPU in a sense, so my 16gb is dedicated to the system and other 8gb can be shared with gpu
 
Dec 11, 2020
6
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10
Was the RAM working in dual channel mode in slots A1 & A2?
It could be that something was wrong with the motherboard from the beginning.

The Asus 1080 has 8GB of VRAM and it does not be share the RAM from the system.
Yup dual channel mode on slots a1 and a2 .. and the system is giving an extra 4gb of RAM from my 16gb to my GPU's 8gb vram for a total of 12gb is what it shows in task manager in the performance tab. memory shows 16gb ram useable and seems normal. If I move the 16gb kit to the proper set up via the motherboard manual (a1,b1.. a2,b2) it only shows 8gb useable with 8gb reserved. When I set it to a1,a2 it shows the whole 16gb kit. And runs like normal, dual channel and 1866mhz. And I can at this point, add my 8gb Corsair ram, single stick, to any other slot, and it shows as hardware reserved. However, when I check it in bios, it is there, and I have the option to set the DOCP profile like the XMP I was told boosts the ram speed. With just the 16gb, I see the DOCP profile as well and can turn it on with no issue, as well as the 8gb, but when I get to windows it only sees the 16gb kit. So I stopped trying with the extra 8gb stick and put it in my 2nd PC for my kids, no issues there.

Only weird part is that the 16gb kit is only working properly on slots a1,a2 and not the proper way it should... and this is brand new ram I bought last Fall when I started building this monster. I have read that alot of other users are seeing the same issue; and I have followed many different steps in order to achieve some sort of success, with none to be found.

I find my RAM sits too close to my CPU cooler and I just wanted to move it for peace of mind and to follow the proper set up instead.
 
Yup dual channel mode on slots a1 and a2 .. and the system is giving an extra 4gb of RAM from my 16gb to my GPU's 8gb vram for a total of 12gb is what it shows in task manager in the performance tab. memory shows 16gb ram useable and seems normal. If I move the 16gb kit to the proper set up via the motherboard manual (a1,b1.. a2,b2) it only shows 8gb useable with 8gb reserved. When I set it to a1,a2 it shows the whole 16gb kit. And runs like normal, dual channel and 1866mhz.
I don't know if your motherboard BIOS has a feature to allocate system RAM to a dedicated GPU. If it does, it should be under Advanced tab ...something related to Graphics Settings, Video Settings, or VGA Share Memory Size.

And I can at this point, add my 8gb Corsair ram, single stick, to any other slot, and it shows as hardware reserved. However, when I check it in bios, it is there, and I have the option to set the DOCP profile like the XMP I was told boosts the ram speed. With just the 16gb, I see the DOCP profile as well and can turn it on with no issue, as well as the 8gb, but when I get to windows it only sees the 16gb kit. So I stopped trying with the extra 8gb stick and put it in my 2nd PC for my kids, no issues there.
Your motherboard only supports 1, 2 or 4 RAM modules, so installing 3 RAM modules could end up in unpredictable results.

Only weird part is that the 16gb kit is only working properly on slots a1,a2 and not the proper way it should... and this is brand new ram I bought last Fall when I started building this monster. I have read that alot of other users are seeing the same issue; and I have followed many different steps in order to achieve some sort of success, with none to be found.
That issue could be caused by different settings, hardware , software, BIOS or the OS. That is why trying to follow a fix that worked from someone else might not help.
It could help
In some cases when the right amount of RAM is shown in the BIOS , going to Windows System Configuration could fix it
Open MSconfig as admin.
Select the Boot tab and click the Advanced options... button.
See if Maximum memory is checked and how much RAM is show.
If is checked uncheck, save and reboot. If it is unchecked, check the box, select the maximum amount of RAM and reboot.
The go back uncheck, save and reboot again.

I find my RAM sits too close to my CPU cooler and I just wanted to move it for peace of mind and to follow the proper set up instead.
The RAM sitting close (but not touching) to an air cooler is beneficial since it could keep the RAM running cooler.