What a CPU can address and what the chipset allows it to address are different things, as I have understood.

The largest EDO sticks I have are T-shaped 256 DIMMs. The household socket 8 chipset i440FX chip allows for 4 such sticks, resulting in a whopping 1 GB of EDO (or FPM or even BEDO), so that's a no for 4GB. The later i440GX allows up to two GB of Sdr-Sdram (no EDO).

Even the behemoth ALR 6x6 "only" allows up to 4GB of ram (and only FPM!) to be used by up to 6 PPro's.

So in my limited knowledge, there's no way to have more than 1,2 or 4 GB of ram in a s(l)ocket 8 system per cpu.

The Proliant 5000 (R) with the EDO RAM updated memory boards was able to hold 8 of the beforementioned T-shaped 256 MB sticks on each of his two memory boards resulting in the 4 GB total memory.
https://www.cnet.com/products/compaq-proliant … hz-128-mb-0-gb/
I did not try this myself yet, allthough the parts are availiable.
Interestingly for the Proliant 5500 6/200 (there is a XEON 5500 as well) a max of 3 GB is found, allthough it uses the same type of memory and has the same number of memory slots.
Netserver LX pro 6/200 might be capable of 4GB EDO DIMM as well, while the technically identical IBM PC Server 704 is only specified for 2 GB.
For all these 4 socket systems it should be possible to reduce the CPU count to 1, so all memory is available to a single CPU.

But yes, I am not aware of any socket 8 system exceeding the 4 GB limit.

My guess would be that this feature was used only in super computers at this time. So commercial servers won't cut it.

flupke11 wrote on 2020-07-27, 10:38:

What a CPU can address and what the chipset allows it to address are different things, as I have understood.

Back in the early 90s, people used to like to boast about how the 386 and 486 CPUs could handle up to 4GB of RAM conveniently not mentioning that this number was entirely meaningless as pretty much every 486 motherboard at the time only supported up to 32MB (in some extreme cases 256MB).

Can the L2 cache address >4GB?

Memory over 4Gb is Paged into a window under 4Gb with PAE as far as i know
So it should be Cached too

Ppro is Caching 4Gb.