Standard DRAM Memory

[caledonia]

hello this is what i have just now on a ASUS A8N SLI PREMIUM see under photo

but when i do the test it says DDR 3200 which is correct but it also says ddr400 what is this ddr 400 as i see no reference to it in the under photo (is it the speed if so mine says 200 and can they be mixed or maybe i am barking up the wrong tree)

I have 4 slots just now with each having 512 of what is in the pic below and want to upgrade just 2 slots to 1 gig each making it 3 gigs all in (with the other 2 still having what is in the below pic

[dwilson]

I know  little about this, have no practical experience, am still seeking myself,  but the following link within Crucial may help:

http://www.crucial.com/support/memory_speeds.aspx

The 200/400 might be that if 200 is the board's clock freq., double data rate (DDR) makes this effectively 400 transfers/sec, each transfer (single channel) being 64 bits (8 bytes), hence PC3200 from 8 x 400.

[caledonia]

great thanks mate for that i thought i would not get an answer

now i know what to order

[dwilson]

Forgot to credit Lee Penrod at Directron.org about the clock speed vs. memory data rate. If you decide to do the upgrade, there is a fine tuning issue. It did not matter when all 4 modules were identical 512, but with mixed sizes it might make a difference which slots. Probably it's worth consulting motherboard manual or ASUS, since for some Intel boards their manual advises putting one matching pair in slots 1 and 3, the other in 2 and 4. That way the faster 2 channel mode is obtained, otherwise only single channel, although all the modules work either way. The Intel boards colour code the slots such that one pair is blue, the other black. There is a thread on this forum that also might help: http://forum.crucial.com/t5/Standard-DRAM-Memory/Ram-not-shown-in-slots/td-p/4570;jsessionid=43D8C47... One might think, why not get 4 x 1GB to simplify, but there seems to be a problem that the 4th GB will not be even half used because a 32 bit O/S needs the upper addresses for its own use and one would need a 64 bit O/S to use all 4 completely, and the 64 bit O/S, although faster, tends to need twice the memory of a 32 bit. Possibly I have this garbled but your 3 GB choice seems a sweet spot .

[caledonia]

So basically i am looking for any DDR3200 memory

Is the above statment wrong or correct

[dwilson]

Your statement is correct.  The memory can be described either as "DDR PC-3200",   or as "DDR 400 MHz". They both mean exactly the same thing. Since the bus is 8 bytes wide, 8 bytes x 400 MHz = 3200 megabytes per second throughput. That's about one third the size of my hard drive in one second !

But there are various kinds of memory :   buffered/unbuffered, ECC/non-ECC, registered/not registered, and it may come in different voltages. The Crucial scanner should select only the type which your motherboard needs.

Or, if you have the board manual, it may tell you all these details, which you would need to know if you are going to a store. If it is a good store it would be able to help you.

This all presumes that everything is standard, that the seller or previous owner did not overclock your system in a way that might fool the scanner or make the manual invalid.