What's with the 36 GB option? The other memory configs (16 GB, 64 GB) are still clean powers of two. Size suggests that they're using ECC-capable memory but using the extra width intended to support ECC for data... but why would this only apply to a single size? Part availability?
EDIT: Digging this a bit, it's not (one or more) 72-bit wide busses with 2^32 words as I'd expect as a gray-beard, it's (probably) six 32-bit wide busses with 6 GiB per bus; and this use of 1.5 * 2^N deep memories has become relatively common with the use of IC stacking, with 12 power-of-two sized ICs stacked in a single package (instead of the more "comfortable" 8 high or 16 high stacks of the same ICs giving powers of two).
EDIT: Digging this a bit, it's not (one or more) 72-bit wide busses with 2^32 words as I'd expect as a gray-beard, it's (probably) six 32-bit wide busses with 6 GiB per bus; and this use of 1.5 * 2^N deep memories has become relatively common with the use of IC stacking, with 12 power-of-two sized ICs stacked in a single package (instead of the more "comfortable" 8 high or 16 high stacks of the same ICs giving powers of two).