The short version is, the one with the "I" works, and the one without it usually doesnt'.
I've seen far, far too many cases where the non-I version was inconsistent and unpredictable on Intel boards. I would never risk it.
thanks for confirmation, I was looking for these details and actualy it took some hours last 2 days to get to right discussions and documents. I have found about same.
Although suppliers often sell only regular G version, and the RAM specs show same data as GI, some users mentioned they had problems without -i- version, especialy when in need of support from manufacturer with the issue, I did change of the order to the GI version and wait longer delivery, to avoid problems later, as even simple BIOS update can spoil it, to be safe and not to have 48GB of uncompatible memory :-)
so it probably depends on piece by piece it can work or not, the official version is:
KVR1333D3D4R9SK3/24G is built with the same memory specifications as KVR1333D3D4R9SK3/24GI , but the components used to manufacture them may not all be certified by INTEL - basically some builds are certified, others are not.
To ensure that customers who wish to use only INTEL certified parts do not receive non-certified builds, we created the KVR1333D3D4R9SK3/24GI sku.
If you do not necessarily need to use the INTEL certified parts, the KVR1333D3D4R9SK3/24G should be fine to use.