Software to benchmark ram speeds through whole range

[mackerel]

This is a bit niche perhaps, but I might need to look at unbalanced memory configurations and I'm wondering how to actually test it? By unbalanced, I mean, some or more of different capacity, rank, bank per channel. I'm mostly interested in confirming how dual channel works e.g. if you have 2x4GB on one channel, and 1x8GB on another. I'd expect it to be dual channel through the range, but I don't know how to confirm that. I'd need something like a HD benchmark which samples though the space. Hmm... I suppose I might have given myself a possible method there, by setting up a large ramdisk I could run disk software on it. If it can keep up with the data rates! But I can't know for sure how it will be mapped to physical ram.

 

[Woomack]

Modern motherboards support asymmetrical dual channel or flex mode or whatever it's called. As long as it's supported, then it works faster than a single channel but slower than a symmetrical dual channel.
If you run it on an older motherboard without the support for asymmetrical configurations, then it will run as a single channel.

To check actual bandwidth, you can use the same AIDA64 as for all other RAM tests. To get other types of results, you can compare them in Geekbench or tests like PCMark Applications or Blender, which reacts to RAM performance quite well. I don't have anything on my mind that uses a lot of RAM other than the 7-Zip benchmark. It actually uses close to max capacity, and you can compare results in compression/decompression.
RAM Disk is usually limited, and results are not exactly as high as expected. For example, the last time I was checking, I had about 13GB/s bandwidth while RAM itself could make 40GB/s+.

 

[mackerel]

As far as I'm aware those programs will just test some allocated ram and give a result. I want to target specific areas. Say I have a system with 4+8GB modules for 12GB space total. You'd expect the first 8GB to be in dual channel, and the last 4GB in single channel. I want to be able to see that.

I only thought about HD test software since HD speeds do vary across their capacity, and is the nearest I can think of to do this via ram disk. I guess I should add, I don't need to know a precise bandwidth value since it varies depending on how the test is implemented anyway. I need to be able to see the relative performance in different zones.