Memory Question for technically savvy

From Anandtech article: "RAM - Memory Technology Overview"
http://www.anandtech.com/memor...oc.aspx?i=2223&p=5 (paragraph 5)

After a row in a memory chip is activated, it cannot be closed and another row in the same bank be opened until a minimum amount of time has elapsed. This is why having more memory banks can help to improve memory performance, provided it does not slow down other areas of the memory.

However, it is also known that data travels faster inside a memory chip than on the physical data bus and pin connections. Perhaps its safe to say that having fewer high density chips is better in this regard.


Wondering if you guys can shed some more light on this subject:

Which memory module configuration offers better performance in theory:

DDR400 PC3200:
1GB module 128Mx64, built using: 64Mx8, 16 chips, 2 memory banks
1GB module 128Mx64, built using: 128Mx8, 8 chips, 1 memory banks

I believe the guys at crucial and other manufacturers will go with the configuration that is more cost effective whether it be (64Mx8) chips or (128Mx8) chips. Between the two, usually (64Mx8) is a more cost effective configuration.

Also, many retailers hide the chips they are using from consumers by placing heat sinks on the modules. However, the heat sinks do offer better performance. In few cases the heat sinks can be used to cover countefeit chips. Crucial is a very reputable source and I highly doubt you would get bad modules from them since they typically use Micron original chips to build their modules.

But it still leaves the question of which configuration offers better performace ...in theory.

I am hearing that fewer banks/module offers better performance, but I am not sure. The reason being that it takes less time to find a block of data with fewer banks, less phyical connections, and fewer higher density chips.

This could be incorrect.

Yes for PCs the difference is minimal.

But for example... if you have a server with a high volume of memory... such configurations could become an issue.

The more memory you use, the more significant small issues get.

I would be curious to know if this is an issue.

If it were possible to access two banks of a memory module simultaneously, then it might make sense to say that two banks is better than one bank.

2 banks = twice the money! haha. (ok lame joke)

Thanks for your reply Mr. Crucial Labs. Very informative. =P

I just wanted to add that 64Mx8, 16 chips is a popular configuration for 1GB modules.

And also that all though I'm not seeing many 128Mx8 configurations for 1GB modules, I have seen many 2GB modules built from 128Mx8, 16 chips.

cheers !

There are a few module manufacturers, including ourselves, who are building 2GB using 128Mx8, 16 chips.

Though we do not represent the retail market.