Is it possible to supply other RAM for the old server instead of the one specified in the specification?

Question

Iron

There is an old host on Xeon e5520, On the motherboard s5520hc.
The specification of the processor is ddr3 1066\800, but there is absolutely no such memory at hand, it will take too long to wait for delivery.
What kind of memory can be plugged in as an alternative?
Will another ddr3 RAM with ECC at a frequency higher than the specified one (for example, 1333 \ 1600) work at a reduced (up to 1066) frequency. The question is urgent, but I am an enikey worker (
Helpanite plz.

Answer 1

Will work.
https://ark.intel.com/products/36599/Intel-Server-...
Memory supported: DDR3 ECC UDIMM,
RDIMM which it was officially tested
www.intel.com/content/dam/support/us/en/documents/...

Answer 2

can. will operate at a reduced frequency.

Answer 3

Most likely it will, but not sure.
That is, it is impossible to predict the result in advance.