Question 4GB out of 12 GB RAM is being hardware reserved.

[SM4SH]

EDIT: In case anyone else encounters this, reseating my modules fixed the issue for me.

A while back my PC was running with 4x2 in dual channel mode but recently one of the modules died.

So I got another 8GB module of the same brand but its completely different in size, speed and timings. I read that there was this thing called flex mode which might run 2 different modules in dual channel so I was hoping to work with that.

After I installed the new module I looked into task manager and it showed that 4GB of RAM was being hardware reserved.

I checked with CPU-Z to know whether I was running in dual channel and it shows that it is in dual channel.

So I was wondering whether the 4GB being hardware reserved is because of flex mode, maybe it reserves it like a cache or something? or is that not the case? Is there anyway to know if its running in flex mode?

 

[PC Tailor]

Welcome to the forums my friend!

First port of call with mixed RAM is if they work at all together in the first place, which is more likely the issue you are facing. Is the other RAM module identified in the BIOS?

RAM modules are only guaranteed in the form sold (from the same pack). So it's a 50/50 gamble whether a new set of modules will work with the old. Ultimately each module is made with different chips, different silicon etc.

This is because the manufacturing of the modules changes frequently, making them the same make/model/timings is irrelevant. That is just a way to try and minimise potential conflict, but not eliminate it.

Flex mode is just a way of trying to make sure RAM modules of different sizes could still run in dual channel mode, say if you had 2x4GB and wanted to add another 8GB, flex mode could allow you to potentially run 8GB in each channel, but doesn't mean the RAM modules will work together in the first place.

 

[SM4SH]

Welcome to the forums my friend!

First port of call with mixed RAM is if they work at all together in the first place, which is more likely the issue you are facing. Is the other RAM module identified in the BIOS?

RAM modules are only guaranteed in the form sold (from the same pack). So it's a 50/50 gamble whether a new set of modules will work with the old. Ultimately each module is made with different chips, different silicon etc.

This is because the manufacturing of the modules changes frequently, making them the same make/model/timings is irrelevant. That is just a way to try and minimise potential conflict, but not eliminate it.

Flex mode is just a way of trying to make sure RAM modules of different sizes could still run in dual channel mode, say if you had 2x4GB and wanted to add another 8GB, flex mode could allow you to potentially run 8GB in each channel, but doesn't mean the RAM modules will work together in the first place.

Both of the modules are being identified in the bios, task manager and also in CPU-Z which also says it's running in dual channel.

I was thinking that the 4gb being hardware reserved is how flex mode works but so far I haven't seen anything online that shows that's the case.

Do you know how I can find out if the RAM is running in flex mode?