Why are consumer PCs so limited in RAM capacity? [closed]

Question

Now that systems are 64-bit, why do manufacturers still limit most PCs (laptops and desktops) to a paltry RAM capacity of 4GB - 8GB?

In '94 I paid an extra $300 when I ordered my first PC to increase the initial RAM from 8MB to 16MB... but the system capacity was a generous 768MB, which I eventually maxed out. However, I never see new systems with any sort of headroom for future expansion.

Is this a ploy by manufacturers to keep people upgrading entire systems more often, or is there some technical reason I'm not aware of?

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Edit: By including the anecdote about my 16MB PC I was hoping to avoid responses like "Why would you ever need more than 8GB of memory?"

It's not that I think anyone needs more than that right now. It's just that I like to have that "headroom"... that feeling that I didn't just by a machine that's at it's maximum capacity shortly after buying it. And since people like the SuperUser community influence a lot of the purchases that other people make, I'm surprised that hardware manufacturers don't cater to us more in this respect.

It seems that the current hardware limitations built into most consumer PCs are artificial, and if a PC manufacturer simply allowed the highest capacity possible given the architecture they would receive a lot of attention from enthusiasts and all of the purchases they influence.

Answer 1

While the 64-bit Windows supports up to 128GB memory,
there is a limit to the capacity in a DDR2 memory module,
and, a limit to the bandwidth and latency advantage over each module (see DDR3 with Nehalem too).
There is also cost to add extra slots on the motherboard.

You also have to remember that 64-bit OSes are not yet supported by a lot of applications (look up other questions here on that).

Having said all this, there are server machines that need a lot more memory,
their mother boards have more slots (for whatever it costs).
Stackoverflow has recently seen a server upgrade to (guess what?) 'just' 24GB.

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Update: recent upgrade was actually 48GB...
Stack Overflow Architecture
And, they run SO/SF/SU database over that.
So, what do you think consumer PCs need?

Answer 2

I don't know the exact answer for the limitation, it likely varies by PC manufacturer, but I have a few ideas:

• The market doesn't demand more memory. If PC manufacturers thought they could make more profits selling systems with more memory, then they would. Likely, the sweet spot is about half way in between the smallest and largest memory configuration offered.
• Consumer PCs typically use unbuffered memory. This is done because you can get higher frequencies at a lower cost due to lack of buffering at the expense of signal loading which limits the amount/size of the memory modules you can populate. Registered memory is typical of a server class computer system. Registered memory buffers the signals for improved signal quality and has ECC for error detection/correction.
• Memory controller limitations. This is affected by what type of memory you have, but memory controllers have their limitations such as number of memory clocks provided. DDR2 unbuffered memory requires 3 clocks per DIMM module, DDR3 UDIMMs (unbuffered DIMMs) require 2 clocks per DIMM module, DDR2 & DDR3 Registered memory require 1 clock per DIMM module.
• Board area = features. If the motherboard were designed to handle more memory DIMMs, that could leave less room for integrated features.The typical consumer form factor (ATX) is 12 in. x 9.6 in. Server form factors have much more flexibility, for example the "EATX" form factor is 12 in. x 13 in.

Answer 3

32 bit systems have a theoretical maximum of 4gb of addressable memory.

Also, on a windows system that 4gb is split into 2gb kernel space and 2gb user space.

There are various quicks and hacks* that can have some effect on this, but unless you have very specialized applications there isn't really much point in putting more than 4gb in a home system.

Gradually, as 64 bit becomes the norm we will start to see systems with much more ram available.

(*PAE = physical address extension and windows /3GB switch are two examples)

Answer 4

Most people will never need more than 8GB of RAM? Unless you're doing serious video/audio/image editing, CAD, or stuff like that, there's no way you're going to use that amount of RAM; and if you are, they want to sell you something higher end - a workstation, perhaps with Xeon processors.

Answer 5

For the average user, there really isn't a need for more than 4gb of ram, or maybe even 2. I have 6gb on Vista, and even with I have multiple games open, a billion chrome tabs open, tweetdeck, vent, winamp, etc, etc I never see my memory usage go past 60%

Answer 6

Because we have netbooks!

Users simply do nit need any more than 2 GB of RAM. to reflect this, companies save money by not 'implementing' higher RAM capacities on the motherboards.

Those that do need high amounts Of RAM will find the right plac and hardware fir their job.

Answer 7

"640k is Enough For Anyone"