[SOLVED] Why do Intel 64-bit CPUs like the core i7 are limited to 32GB RAM, as listed in their official specs?

[mrAS2020]

...because the entire internet will tell you that the RAM limit for 64-bit CPUs is 2*64, or something like that? I spend a fair amount of time digging through various answers to that question and have yet to find one good explanation for this? Now I'm happy to be corrected, just please follow the "ffs..." with a decent "because...".

Just look at this guy: totally badass 64-bit CPU with...32 GB RAM tops? I don't get it. Not when

Intel® Core™ i7-3920XM Processor Extreme Edition

Operating System	Maximum Memory (RAM)
Windows 10 Home 32-Bit	4GB
Windows 10 Home 64-Bit	128GB
Windows 10 Pro 32-Bit	4GB
Windows 10 Pro 64-Bit	2TB

So everyone on the planet has been saying that 64 bit architectures can handle terrabytes worth of RAM, but Intel says no? Why? I really don't get it. And I know motherboards have their say, but intel is saying "I don't give a **** that you have 200 SO-DIMM slots, screw you, I only do 32" ?

(edit 1: spelling & title)

 

[Roland Of Gilead]

Hey there,

So there's a couple of things going on.

On one hand, you have a software limitation, which relates to 32bit/64bit, and the amount of memory each OS can address. 32-bit can only address 4gbs so any more than that is a waste.

On the other hand, you also have a hardware limitation, where some motherboards support from 32gbs up to 128gb and higher. It's different for each level of mobo. The more expensive models may have higher ram capacities. Bu you have to pay for the privilege (along with the cost of extra ram modules)

Also playing a part here is the age of the hardware. Older hardware didn't require terabytes of system memory, so as applications/OS/Games have become more resource hungry, I.e Need higher amount of ram that can be put in the system, and an OS that can make use of that ram, the hardware specs increase to accommodate the new software requirements.

A good example will be my own system. My motherboard has a max capacity of 64gb and has four slots to put memory in. So in theory I could have 4 x 16gb Dimms, or 2 x 32gb or variations like what I have 2 x 8gbs. I don't require more than 16gbs for my gaming system. But if you were editing, or content creation then having more ram will help. But at some point you hit the limitation of the mobo.

In terms of Intel 'screwing' consumers. That can be argued either way. I would agree with you a little, in that Intel have historically limited their ecosystem, in terms of features, so people would buy more expensive mobo's. AMD on the other hand, offer much more with respect to hardware features and access at often cheaper price points.

 

[USAFRet]

i7-4970k
https://ark.intel.com/content/www/u...-4790k-processor-8m-cache-up-to-4-40-ghz.html
32GB

i7-6700k
https://ark.intel.com/content/www/u...-6700k-processor-8m-cache-up-to-4-20-ghz.html
64GB

i7-7700
https://ark.intel.com/content/www/u...7-7700-processor-8m-cache-up-to-4-20-ghz.html
64GB

i7-8700k
https://ark.intel.com/content/www/u...8700k-processor-12m-cache-up-to-4-70-ghz.html
128GB

i7-9700k
https://ark.intel.com/content/www/u...9700k-processor-12m-cache-up-to-4-90-ghz.html
128GB

 

[Rdslw]

one simple reason a max of 32GB sticks (4x8) could be inserted into the banks.
a lot of laptops had this limitations now broken as you could for example insert 16GB ram into macbook air 2013 that listed 8 as max, because there was only 1 slot and 8GB sticks were biggest ones in 2013.

we will have same thing with boards listing 32GB limit as 32GB per stick appeared on market recently.
limits are set by 4x number of sticks, so 4x 32 GB sticks == 128 GB.
on boards that had 2 slots and listed 32GB, you should be able to use 64GB.

 

[USAFRet]

ANd your i7-3920XM example is 8 year old architecture. Long before WIn 10 was released.

 

[mrAS2020]

Thanks everyone, I'll try to digest all that. I appreciate you all taking the time to educate my confused mind. For my defence I've been comparing thousands of different specs/models/chipsets/socket//etc combinations that I'm saturating a bit.

 

[USAFRet]

CPU, motherboard, RAM, and the operating system all work together.

It makes no sense to devote resources to the CPU to handle 128GB RAM, if that does not yet exist and the OS of its time cannot utilize it.

You original linked CPU was from 2012. That was right in the middle of Win 7.
And for mobile devices as well.

Laptops generally have only 2 slots. Larger RAM sticks literally did not exist in that form factor.

 

[mrAS2020]

Well I guess when computers are used to calculate the optimal way of sucking every penny out of every living thing on the planet, finding what you want gets technical. Cheers and good luck with the builds. There's some cracking stuff coming out, but what a mess.