Finally got tired of my Ryzen 5700U showing in CPU-X as "Summit Ridge"

[tlmiller]

So I downloaded, compiled, and installed the latest libcpuid from the github repos. YAY, it finally recognizes it as Lucienne!!!

[crosscourt]

LOL! Glad you got it working.

[wove]

Processors just confuse me. I have a first generation i7 "Westmere" m620. According to Intel's specs this processor can address 64GB, yet according to Intel the processor is limited to 8GB of RAM onboard. Why address 64GB if it can only use 8GB? The MacBook Pro model this one replaced used a C2D processor that could use 16GB of RAM.

My best guess is that Intel's HD graphics must map itself into the top 512MB of installed RAM with it having a limit of seeing beyond 8Gig, thus limiting the cores to using RAM below that, there by creating the 8GB limit. But that is speculation on my part.

[crosscourt]

Your speculation is possible but its probably got more to do with the type of motherboard they used and what was available at the time.

[tlmiller]

There's 2 main reasons for the limitation.

The first is a simple physical limitation. 2 slots of RAM, can access 64 GB, but the largest DIMMS it's able to access at the time of the chipsets production are 8GB...so while it COULD access 64GB if there were 8 slots, with only 2, it would be 16GB.

The second is simple capitalism. OEM's will (in the past this was MUCH more common than it is now) have BIOS crafted that will intentionally artificially limit the amount of ram that the board can see. Thus although the chipset could for instance see up to 32GB ram, the BIOS artificially limits it to 8GB. Why? Greed. Why let you upgrade your system when there's a newer system that can take 16GB that they can sell you instead?

There are, of course, other reasons, but those are by far the 2 most common reasons I've ever seen. The second was far more common in the aughts and teens (when AMD wasn't competitive and Intel basically was a monopoly above the low end), the first is by far the more common reason nowadays.

[wove]

It is nice to see that I am not the only raving cynic. Apple tends to spec maximum RAM based on what is available at the time, so it is common for older Apple hardware to use more RAM as larger sizes of the right spec become available. But Apple also does use method two as well. In the early MacBook Pros, the firmware mapped the Mac ROM in at 6 gig and if you go beyond that software will just over write the ROM and the system will crash.

I do have 16GB of RAM in the X230 which is the right spec and I could install it just to see what happens, but overall I think the X230 makes better use of the RAM, than the MBP would. I am not aware off hand of any other hardware that uses Intels 1st Gen i7 to check and see what they say about maximum RAM.

[crosscourt]

Its also about cost as back then 64gb of ram wasnt cheap and oem boards were intentionally designed to be lean to reduce costs. Its all about what motherboard/chipsets were available at what costs.