PCI RAM Extender Cards?

stevejsmith asks: "I'm going to buy a Dell computer which supports DDR RAM, however it only comes with two DIMM slots. I have lying around two 128MB sticks of RAM, and want to use them. I know RAM is cheap, but I want some way to put more than two DIMMS in this system. Short of getting a new motherboard, is there any way I can add more RAM? On Slashdot I remember seeing a PCI card that help RAM for a RAM drive, but is there such thing as a PCI card that just held regular RAM for system usage? If not a PCI card, any other suggestions?"

Comments

Don't buy an unexpandable Dell?

[Toraz Chryx]

Putting ram on a PCI card is a bad idea in this day and age, peak PC2700 memory bandwidth is 2.7GB/s, peak 32/33 PCI bandwidth is 132MB... that presents something of a bottleneck :)

Just buy a computer with a sensible number of dimm slots to begin with.

Not going to work

[AnimalSnf]

I'm not going to go into as great a detail as I'm sure many other posters will, but the best way to understand why is to go to a hardware site like Tom's Hardware or Anandtech and read a review of a motherboard or a chipset.

Of all the things that a motherboard (or more specifically the collection of microchips known as the chipset) connects together the connection between the memory and the processor is the fastest the most important to performance. No other link, except between the processor and the motherboard even comes close in importance. Also, another issue that comes up is what is known as latency. Latency is the delay the system experiences when it requests memory access. It's not just how much data you can transfer, but how quickly you can have it after you ask.

For all those reasons it almost always makes sense, especially at today's prices, to have all the same memory modules in your system and the fastest memory your system can support. Even if you are able to recycle memory I would avoid doing so unless stability is an issue as many technical issues arise when DIMMS are mixed and matched.

Re:Not going to work

[Toraz Chryx]

In addition, having system ram on the PCI bus will make PCI device performance (sound/IDE etc) suffer quite dramatically.

Not worth it...

[tunah]

The performance hit from this will negate any benefit you will get - you might as well just leave out the ram as it will be slowed down to PCI speed. As you said, RAM is cheap, so sell what you've got and buy one or two 512MB sticks.

Re:Not worth it...

[tunah]

Point taken, but you will get something for it to offset the cost of the new ram.

Depending how cheap ram is at the moment, it might not be worth it, in which case find a friend who doesn't have much ram and give them the chips. Many people don't realise how much of a difference going from 128M to 256M or 256M to 384 or so makes.

Ask Slashdot: PCI RAM Extender Cards?

[Wrexen]

Posted by Cliff on Sat November 16, 03:13 PM
from the I-have-no-idea-what-bus-bandwidth-means dept

Mmmm, bus RAM

[pete-classic]

Bus RAM made sense on my 286 running windows 3.0. Real-mode paging was a real step up from the 1M memory limit.

Today it doesn't make any sense.

OTOH, the ram drive you mentioned might make sense (except that it is pretty expensive) if you used it for a swap partition.

I think that a better overall plan would be:

1. Don't buy a RAMBUS based system.
2. Buy one that supports an unreasonable amount of RAM, with only one slot populated with the largest module it supports. In a few years it won't seem like so much.
3. Reconsider buying a Dell. If you know how many DIMM sockets it has you aren't the target customer.

-Peter