Modifying the OG Xbox to have 256M of RAM [video]
1–10 of 38 posts
Re: Modifying the OG Xbox to have 256M of RAM [video]
#2Amazing that this is possible. Also saw a video of upgrading a Nintendo Switch to 8GB of RAM https://www.youtube.com/watch?v=J4oXmQGZgzU
Re: Modifying the OG Xbox to have 256M of RAM [video]
#3Neat! I've been loving the Xbox Arms Race recently.
Re: Modifying the OG Xbox to have 256M of RAM [video]
#4Since it was mentioned in the Macho Nacho video, this was quite a hurdle. But it does bring up the question, what is the theoretical maximum possible? I know the CPU was 32-bit, so 4GiB is the upper limit in that regard. I don't know if the CPU has limited address lanes or any other physical limitation though. The max I've seen discussed is 1.5GB for a similar cpu on a normal desktop and 640MB for the test design of the xbox (the literal pc version, not the dev kit).
Re: Modifying the OG Xbox to have 256M of RAM [video]
#5The real question is if this will stop Morrowind from secretly rebooting the XBOX at certain load screens.
Re: Modifying the OG Xbox to have 256M of RAM [video]
#6Since it was mentioned in the Macho Nacho video, this was quite a hurdle. But it does bring up the question, what is the theoretical maximum possible? I know the CPU was 32-bit, so 4GiB is the upper limit in that regard. I don't know if the CPU has limited address lanes or any other physical limitation though. The max I've seen discussed is 1.5GB for a similar cpu on a normal desktop and 640MB for the test design of…
I can't figure out if the xbox processor supports PAE or not. But references say most Intel processors after pentium pro, including Pentium III support PAE. Probably with 36 bits of physical addressing. But it's a mobile socket; no idea if they put all the address pins out on those.
Re: Modifying the OG Xbox to have 256M of RAM [video]
#7Since it was mentioned in the Macho Nacho video, this was quite a hurdle. But it does bring up the question, what is the theoretical maximum possible? I know the CPU was 32-bit, so 4GiB is the upper limit in that regard. I don't know if the CPU has limited address lanes or any other physical limitation though. The max I've seen discussed is 1.5GB for a similar cpu on a normal desktop and 640MB for the test design of…
As the pentium 3 used the chipset for the memory controller, it's likely limited by that, though you'll likely struggle to find specs at that sort of level publicly available. Though assuming it's the same as contemporary consumer nForce chipsets may be a good assumption [0], which may be where the 1.5gb limit discussed came from.
And the p3 also supported PAE [1], so technically could address more than 4gb of ram. Though software support may be lacking - I think on the original xbox the app ran in ring0 so did things like page table management itself, rather than the "OS", so would likely require significant per-game modifications.
[0] https://en.wikipedia.org/wiki/Comparison_of_Nvidia_nForce_ch...
[1] https://en.wikipedia.org/wiki/Physical_Address_Extension
Re: Modifying the OG Xbox to have 256M of RAM [video]
#8Since it was mentioned in the Macho Nacho video, this was quite a hurdle. But it does bring up the question, what is the theoretical maximum possible? I know the CPU was 32-bit, so 4GiB is the upper limit in that regard. I don't know if the CPU has limited address lanes or any other physical limitation though. The max I've seen discussed is 1.5GB for a similar cpu on a normal desktop and 640MB for the test design of…
> I know the CPU was 32-bit, so 4GiB is the upper limit in that regard.
Not necessarily. Just because a CPU has a 32-bit virtual address space doesn't mean it has a 32-bit physical address space. PAE (Physical Address Extension) is a paging mode for x86 CPUs that offers a 36-bit physical address space on 32-bit CPUs.
Re: Modifying the OG Xbox to have 256M of RAM [video]
#9The real question is if this will stop Morrowind from secretly rebooting the XBOX at certain load screens.
Modders have done some incredible work optimizing and bug-fixing Morrowind over the years. I'm curious if someone could mash all of that together and 're-pack' an Xbox version of the game that ran way smoother.
Completely pointless? Yes. Interesting? Also yes!
Re: Modifying the OG Xbox to have 256M of RAM [video]
#10Since it was mentioned in the Macho Nacho video, this was quite a hurdle. But it does bring up the question, what is the theoretical maximum possible? I know the CPU was 32-bit, so 4GiB is the upper limit in that regard. I don't know if the CPU has limited address lanes or any other physical limitation though. The max I've seen discussed is 1.5GB for a similar cpu on a normal desktop and 640MB for the test design of…
As the pentium 3 used the chipset for the memory controller, it's likely limited by that, though you'll likely struggle to find specs at that sort of level publicly available. Though assuming it's the same as contemporary consumer nForce chipsets may be a good assumption [0], which may be where the 1.5gb limit discussed came from. And the p3 also supported PAE [1], so technically could address more than 4gb of ram. T…
True, I didn't know PAE was a thing till now. I figured something like that was possible, I just didn't know we had it around the time of the xbox. I guess that raises the current theoretical limit to around 64GiB? And yeah even the chip presented in the video was also noted that even 256mb wouldn't provide any benefits to games, only to homebrew or game mods and even that was overkill for anything that currently exists.
Thanks for the info, I'm going to look more into it later and see if I can come up with anything more concrete.