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I can't sleep, so have a rant: memory limitations.

I'm supposed to be getting up at 4:30am, but at this rate I'll just already be awake at that time and have to suffer through the day; not a problem though, I'm taking the day off work for various reasons.

Now, at the moment I'm writing this using Firefox on FreeBSD on my netbook, because, well, they were right. The PC-BSD 9.1 RC version just suddenly fixed the problem with the Intel driver. Credit given where credit is due; if I'm being perfectly fair, this OS does everything I want for a netbook aside from minor issues with power management (no hibernate, so far as I can tell) and I can't use Truecrypt. Hardly deal-breakers. Oh, but my screen goes haywire and craps itself if I try to access the separate TTYs, which makes me a little sad.

Anyway. Yay, experimentation is fun!

What isn't fun is the conflicting information I'm getting about a certain issue, and it might be relevant to some of y'all too, so it might be worthwhile to put this out there.

My main laptop came with 4GB of RAM, a 1GB graphics card, and Windows 7 32bit. Not too shabby for the time! I still love the thing, and it was a present besides; it's literally the most "cutting edge" of a consumer computer that I've ever owned.

But, my friend recently insisted that the processor was actually a 64bit (Intel) one. I finally got around to checking, and yuuuup! 64bit processor, but they stuck a 32bit Windows OS on it.
No problem, right? Back then, 64bit was comparatively rare and the realm of people who wanted to push their hardware and wallets, so compatibility issues were common.

Now, 64bit is the consumer norm. So, shit's changed, yo.

After realizing that I could've installed 64bit OSs on it, I started to wonder what the implications of upgrading to a 64bit would be. What benefits would I garner, if any, by replacing my Linux Mint installation with the 64bit version?

Turns out, rather a lot, and I'm a little pissed off.

I'm no hardware person, and I have read many conflicting and yet equally plausible explanations of this matter so don't blame me for making mistakes here. If I'm wrong, feel free to correct me, but  snottiness isn't welcome.  
Going by the "worst case", here's the downside to being stuck with 32bit operating systems:

The amount of memory addresses it can access restricts it to being able to use roughly 3.25GB of RAM as a maximum without tweaks. Again, your OS is going to chew some of the available RAM anyway.
This explains why my operating systems read the 4GB of RAM installed, then insist it can use no more than 2.99. That's 1GB gone.

Oh, poo, right? Not that big a deal? Well, here's where it gets confusing and my sources all say different things, but I'm assuming the following is true, because my machine always had memory issues.

OK, first off, part of the "3.3 or so GB actually available" limit is actually chewed up by your graphics card. On a 1:1 ratio. Meaning, with a 1GB graphics card, that becomes one of the 3 gigabytes of memory you can use under a 32bit OS.

It's true that the memory of your graphics card is separate from your RAM, but what matters is how much memory address space the OS can access - so yeah, memory is memory. Your OS can use about 3.3GB out of a 4GB RAM + 1GB graphics card - and to get even shittier, Direct X 9 and under apparently duplicates the graphics card's memory onto the system RAM.

So, worst case, assuming this information I have here is correct, you go from 4GB+1 for a total of 5... to 2. Of which a game's graphics will chomp away on up to half of that, and underlying processes (including the OS) can rape the remainder until, say, your World of Warcraft runs like a piece of crap on a stick.

Which mine does, by the way. So I think it might actually be as bad as this - that the video memory actually counts towards the limit.

So when people say "you don't need or want a 64bit OS until you have more than 4GB of RAM!" they actually should be saying: "you only need one if you have more than 3GB of RAM, a graphics card, or plan on playing current games and rendering software at all, in fact," because it's not a 4GB of RAM limitation per se; it's a memory address access limitation that the OS has to handle, so a graphics card being separate apparently doesn't matter.

Oh, and you have a 2GB limit per application (again, without tweaks, I read somewhere you could force certain applications to break this rule) anyway on 32bit Windows Vista/7. And just hit a quote from Microsoft confirming memory duplication from graphics cards... So, yeah. Seems that's true, and a 32bit application will have a limit of 2GB anyway (with video memory chewing up to 1GB of that).

"Typically, the size of the virtual address space is fixed at 2 gigabytes (GB) for 32-bit applications. How much virtual address space is available is not related to how much physical memory there is on the computer.

A modern graphics processing unit (GPU) can have 512 MB or more of video memory. Applications that try to take advantage of such large amounts of video memory can use a large proportion of their virtual address space for an in-memory copy of their video resources. On 32-bit systems, such applications may consume all the available virtual address space."
-- MS Support

So yeah. Anyone want to confirm, refute or explain this a little better? Not a hardware guy at all. Hell, barely even a computer guy here. My hobby is writing stuff.

Because, if this is even half-true, I need to slap my friend for suggesting I stick 8GB of RAM in this laptop when I first bought it. >:3
Viewed: 38 times
Added: 6 years, 5 months ago
6 years, 5 months ago
It SEEMS legit. The main source of the conflicting accounts is how various OSs use the RAM. I do not know how Linux uses it, but I know that Windows does everything you just said.
6 years, 5 months ago
I began reading, and read a couple paragraphs.
Then scrolled, and fast read...
Then just scrolled...
And fried myself. Uhh...You're talking about computer limitations, there's limitations on not just that, but attention spans of a certain fan base of yours. I can understand what you are trying to say, yet informative talk like this can only go crammed into my teenyweeny yellow polkadoted brain until I can absorb the numbers.

It would be really nice if there was a question that was very basic, and one sentence that I could understand without these numbers crunching everywhere, then refuting it, then debating it, then asking for something completely different. What?
6 years, 5 months ago
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