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How Do Different Memory Options Interact with One Another?

Would it be possible to explain how different memory options interact with
one another?

For example, suppose a computer has 2GB installed RAM and a 1GB Nvidia
graphics card:

  1. What data gets stored in RAM and what data gets stored in the graphics
    card?
  2. Does a portion of the 2GB RAM still get set aside (memory mapping?) because
    of the 1GB Nvidia?
  3. What happens if a 4GB (or 2GB or 8GB) flash drive is plugged in and used as
    Ready Boost?
  4. Which computer would provide the best performance and why:
    • 4GB RAM + 2GB graphics card
    • 2GB RAM + 2GB graphics card + (at least) 2GB flash Ready Boost

I’m thinking I should know the answers, but I’m just not getting my head
wrapped around all of this.

You’re most certainly not alone. The concept of memory in it’s various
flavors, forms, and guises can be very confusing. Add some marketing-speak and
… well, it’s enough to test your memory, that’s for sure.

So, I’ll review the difference between the memory in your system versus the
memory in your video card and why they sometimes overlap.

And then I’ll look at ReadyBoost and discuss why it doesn’t really relate
to either.

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Memory is not disk

I know that this is obvious to many, but it’s a confusion that I see
surprisingly often.

When we talk about “memory,” we are not talking about what is stored or
remembered on your computers internal hard disk. The question I see often
relates to having filled up the hard disk storage on a computer and thinking
that you’re “out of memory”, which is not the case at all.

RAM: Random Access Memory

The term “memory” in most cases refers to RAM – Random Access Memory – that’s the memory that holds
programs when they are running and the data that those programs might
be working on. RAM requires power to be applied to retain what it holds, so
when you turn off your machine, RAM is erased instantly.

The process of booting your computer is nothing more than a glorified and
complex sequence of reading programs – like Windows itself – from the hard
disk, loading it into RAM so that it can be run.

Video memory might be system memory – Or not

Video memory gets confusing very quickly, simply because there are
several possibilities as to how it might be implemented1:

  • The video memory might be completely self-contained on the video card and
    used exclusively by the video card’s graphics processor (GPU). In this scenario,
    video memory actually has no direct relationship to the RAM in your
    machine.
  • The video memory might be “visible” to your computer’s CPU and appear as if
    it were part of your computer’s RAM. In a sense, the video memory is shared
    between the graphics card’s GPU and your computer’s CPU. In this scenario, the
    video memory “counts” against the RAM that your CPU processor is able to
    access. For example, if you have a 32-bit processor, your CPU can only access four
    gigabytes of memory and the video memory that might be shared with your
    graphics card counts as part of that.
  • The video memory might not exist. This is less common of late, but several
    years back inexpensive graphics cards had no video memory of their own and
    simply used some of the RAM in your computer for their purposes. This naturally
    reduced the amount of available RAM for Windows and your running programs.

The good news is that in recent computers, higher end graphics cards often
follow the first model, and the move to 64-bit operating systems makes the
second model irrelevant. Falling prices for RAM have made the third approach
pretty much a thing of the past.

So, with those two things out of the way, let’s look at your specific
questions.

What goes where?

“What data gets stored in RAM and what data gets stored in the graphics
card?”

Nothing that you would recognize gets stored in the video card.

By that, I mean that nothing you might consider the data belonging to Windows
or the programs running under Windows gets placed into video memory. Instead,
that’s what the system RAM is for: your running programs, the data that they
might be working on, and so on all get placed into your system RAM.

Video memory is concerned almost exclusively with the pixel-by-pixel
representation of what you see on your screen.

Consider a display that is 1920 pixels wide by 1080 pixels high – the
current definition of 1080p HD. That’s a total of 2,073,600 pixels. If you’re
using 24-bit, full-color that’s three bytes per pixel at a minimum required to
represent what’s on the display, or around six megabytes.

That’s the kind of thing that gets stored in video memory.

I can hear you saying: but six megabytes isn’t one gigabyte! Indeed. I did say
that it’s the minimum required to hold a pixel-by-pixel representation
of a 1920×1080 display. In reality, many graphics cards have become little
micro-computers themselves. Graphics circuitry now often includes things like
built-in complex 3D functionality, multiple monitor support, and many featurs
targeted at high-speed rendering of everything from animations to immersive 3D
environments.

Ultimately, graphics cards use their memory to perform those tasks behind the
scenes.

Memory cannibalization

“Does a portion of the 2GB RAM still get set aside (memory mapping?)
because of the 1GB Nvidia?”

Maybe.

But probably not.

Unless you have a particularly old and cheap graphics card, it will in all
likelihood bring along its own memory and that will be used without impacting
your system RAM. The only case where this might not be strictly true is the
case of a 32-bit machine in which you have placed a full four gigabytes of RAM.
Your video card might contribute to your system not being able to
access all four gigabytes as system RAM.

ReadyBoost muddies the water

“What happens if a 4GB (or 2GB or 8GB) flash drive is plugged in and
used as Ready Boost?”

Nothing.

At least nothing we’ve talked about so far.

ReadyBoost is completely unrelated to your system RAM and your
video memory.

As a result, adding a flash drive and using ReadyBoost has absolutely no
impact on the concepts discussed above. What goes in system RAM still goes in
system RAM and what happens in video memory stays in video memory.

So what is ReadyBoost good for?

In my opinion, not much.

ReadyBoost, as I understand it, is simply a technology used to make loading
programs into RAM faster. Windows places “some” things onto the ReadyBoost
device so that when they are needed, they are read from it instead of your
presumably slower hard disk.

I know some folks have reported performance improvements using ReadyBoost.
That’s great for them, but I remain very skeptical and typically don’t
consider it worth the effort.

Which is better?

“Which computer would provide the best performance and why?”

Well, my stance on ReadyBoost should be clear by now, so I’ll remove that
option from the table; in my opinion, there’s really no benefit to it and
comparing it in a system configuration without it is very much comparing apples
to oranges.

As for the rest, my standard answer: it depends.

It honestly depends on how you use your computer. It’s very possible that
your usage may not require four gigabytes of RAM.

But, on the other hand, Windows loves RAM and it’s always better to have
too much than too little.

That’s one of the reasons adding RAM is one of my first recommendations for
speeding up a slow system.

So, of the choices presented … more system RAM wins, without question.

My recommendation in general when considering a new machine is two-fold:

  • Make sure that the system you’re about to buy can be upgraded to more RAM
    than you think you need today.
  • Consider upgrading now anyway and putting in the maximum amount of RAM
    now.

The fact of the matter is that systems and software only creep upward in
terms of requirements over time. What worked great in 2GB three years ago might
be struggling today. It’s easier to simply prepare for that eventuality from
the start.

1: As always, I have to point out to the pedants that I’m intentionally
over-simplifying what is almost by definition a very complex topic, meaning
that some of the details may well be glossed over or appear incorrect. My goal
here is to explain only at a high level the types of things going on.

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9 comments on “How Do Different Memory Options Interact with One Another?”

  1. I already have 4G RAM and 32-bit OS. I can upgrade to 8G RAM max, BUT you don’t mention that I need a 64-bit OS to make this upgrade possible… Now, buying 64-bit OS and 4G more RAM can be a bit expensive!!! I have Windows 7 Enterprise 32-bit. My computer originally had Windows 7 Basic 64-bit, but was in Spanish and I had reinstall with Win 7 that was available to me.

    Reply
  2. Many people are confused with the Windows error that “You are running low on memory”.

    “Memory” in this case does not mean RAM.
    Low Memory or Out of Memory does not mean “Not enough RAM”, though adding RAM can sometimes fix a “Low Memory” waning. A “Low Memory” warning usually means that you have exceeded your commit limit. You need either a bigger page file, more physical memory, or both.

    Just to add to the confusion…..

    Reply
  3. What about using a RAM disk? Is it a good idea or not? If it is a good idea, how is a RAM disk best implemented?

    A RAM disk had it’s place many years ago, but no longer. It’s best to let Windows manage your RAM for you and not try to second guess it.

    Leo
    22-Sep-2012
    Reply
  4. @Maurice
    Your Windows 7 enterprise license is also valid for the 64 bit version. I bought Windows 7 Professional and was able to download both the 32 and 64 bit versions. I first installed it on a 32 bit machine and then I took it off the machine when I sold it. I was then able to install the 64 bit version on my new machine and use the same license to register it. I’m not sure about the enterprise version. You’ll probably need to get the installation discs from the company which provided you the 32 bit version and the license.

    Reply
  5. @Frank
    RAM disk was a virtual disk which used some of your RAM and assigned a drive letter to it. It was useful in the DOS days when you used diskettes and had 1MB RAM of which MS-DOS only used 640KB. In that case you would have a RAM speed virtual disk. Now it would reduce your available RAM even more and provide no benefits in most cases.

    Reply
  6. Talk about the old days. When I bought my first new pc from Gateway in 2001, it came with 128MB of RAM.I thought this was fine for WinXP, but when I started adding programs it just froze.They said it was enough RAM to run XP but needed more for everyday use. The machine was 2 wks old and I paid them $150 to boost it up to 256MB which back then was considered all the RAM you would ever need. Boy, does time change things!

    Reply
  7. @Leo and Mark J: Curiosity question:
    I realize that we can’t get into the heads of the promoters of ramdisk software, but I wonder, assuming now that ramdisks are a step backward in time and technology and there’s really no good use for them, why is ramdisk software is so plentiful and being pushed on the Internet for its “amazing” speed benefits? It seems like a scam for no purpose.

    Two causes I can think of: people are misinformed, or it’s a scam for the purpose playing off of people’s lack of understanding and frustration with their computer’s speed to pad the sellers wallet.

    Leo
    23-Sep-2012
    Reply

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