Memory Install - Asus MB

My Asus E1972 manual says it supports up to 2GB. I have 4 x 512MB DIMM and I can't get it to recognize more than 1GB of memory. I have installed them all individually so I know all the DIMM are good.

With all the DIMMs plugged in I get this message on boot.
"Due to chipset limitations this motherboard supports a maximum of 2GB and 4 ranks of memory."

But thats exactly what I have plugged into it!!??
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willcompConnect With a Mentor Commented:
You may have dual rank memory.  There should be chips on both sides of module if that is the case.  2 dual rank modules would max out the 4 rank limitation of your motherboard.

Can't be sure without specific model of your memory.

I have to leave for a while.  Someone else should pick up on this.
Try updating to the latest BIOS?
Some motherboards are particular about what kind of RAM you install in it, and it sounds like one of the pair is incompatible with the motherboard or incompatible with the other RAM.  Check the specs of what will work with your motherboard using the memory configurator program at  Note that if the RAM has different latencies and you are letting the motherboard choose the speed automatically, it may pick the wrong speed for one of the pair and not work.
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I also have an Asus motherboard (P5P800SE), however not the same one as yours. Some (possibly all) Asus motherboards are quite fussy about the RAM configuration.

For instance, I could fill all 4 of my motherboard's RAM slots with 4X 512MB Corsair memory with model number CMXP512-3200XL and have them run dual channel. In other words, I've got 2 gigs of RAM running perfectly with the motherboard.

However, I can only install 2x (yes, two) 512MB Corsair memory with model number VS512MB400 (Corsair Value Select Memory) to make a total of 1 gig and have that run in dual channel. If I tried to install 4x the above RAM sticks, the motherboard would reject it, even though they're by the same manufacturer and on the face of it, very similar to each other.

In short, your motherboard is probably really fussy like mine. In my Asus motherboard manual there is a large table with some example RAM models/vendors and alongside, it tells you what configuration you can use with that RAM (e.g. occupy all 4 slots in dual channel mode, occupy just 2 slots in dual channel mode, occupy just one channel in dual channel mode).

It looks like your motherboard only supports up to 1Gb of the type of RAM you have.
If you do update to the latest BIOS, if you haven't already, there is a possiblilty that this will enable the motherboard to accept the other 1gb.
Sorry, "occupy just one channel in dual channel mode" should have read "occupy just one slot in single channel mode".
elmoredanielAuthor Commented:
I have updated the BIOS, no change.

I know all the memory works because I plugged them in individually.

> Note that if the RAM has different latencies and you are letting the motherboard
> choose the speed automatically, it may pick the wrong speed for one of the pair
> and not work.
How do I set the speed manually??

I checked the manual. I have 2 x 512 Corsair DIMMs that are listed, but they are under a category that states:
"supports one pair of modules inserted into either the blue slots or black slots as one pair of Dual-channel memory"

So does that mean I have to use 2 DIMMs of one brand and 2 DIMMs of another brand, seeing how none of the memory shows up as supporting 4 DIMMs? I don't see how else this Motherboard could ever use 2GB.

elmoredanielAuthor Commented:
> You may have dual rank memory.
Yeah I do, and I bet you can't find single rank DIMMs of more than 256MB, which means ASUS is purposely deceitful. They just lost my future business.
To set timings manually, you have to go to the BIOS setting that's usually labelled Advanced Settings.  Change it from automatically detect (or SPD) to manually set, and select values that are less demanding.  Everest will tell you what the RAM timings are for each RAM as you install it:
SaxicolousOneConnect With a Mentor Commented:
There's gotta be single-rank 512 MB sticks out there. They can't be too hard to find. One thing I am having trouble finding, however, is info about an Asus E1972. Is that the full model number?

Also, it is just possible that you may be able to get your maximum of 2 GB onto this board with two dual-rank 1 GB sticks, leaving two memory slots unoccupied. From a manual for the Asus P5GPL, which also has four memory sockets:

1.7.2 Memory Configurations
You may install 256 MB, 512 MB and 1 GB unbuffered non-ECC DDR DIMMs
into the DIMM sockets using the memory configurations in this section.
• Installing DDR DIMMs other than the recommended configurations
may cause memory sizing error or system boot failure. Use any of
the recommended configurations in Table 1.
• Due to chipset limitation, this motherboard supports a maximum of
2GB total memory and two (2) ranks per memory channel only. A
warning message appears during POST if the total density of
memory modules installed exceeds the chipset capacity. Excess
memory will not be utilized by the system.
• Always install DIMMs with the same CAS latency. For optimum
compatibility, it is recommended that you obtain memory modules
from the same vendor.
• Due to chipset limitation, DIMM modules with 128 Mb memory chips
or double-sided x16 memory chips are not supported in this
There are plenty of single rank 512MB modules.  All that I've purchased in the last year or so have been single rank.  That includes Crucial, Kingston, Corsair, Buffalo, and some others.  Just ensure there are 8 chips on one side of module (requires high density chips).
elmoredanielAuthor Commented:
Sorry, the model number is actually P5GPL

Can you link to some single rank 512's? I don't see how you can search single rank vs dual rank.
I'm eyeballing a matched pair of Corsair VS512MB400 modules and they are definitely dual rank (two sided).  That's some to stay away from.  As best I remember, the last Corsair I purchased was single rank, hmmmm!  Kingston Value RAM dual channel kit

Should be safe with this Kingston RAM.  Kingston inserts a D in model number for dual rank memory.  Plus I have a couple of sticks with similar model number and they are single rank.
Aha, we're in good shape. Just search for that motherboard at any of the memory manufacturer's sites. You'll have more choices than you can shake a stick at in no time! :o)
Gary CaseConnect With a Mentor RetiredCommented:
willcomp's told you what's wrong ... but I'll add just a few thoughts ...

Dalton -- I hope the link you provided is in fact to single rank modules;  but it's not clear that Kingston always appends the rank designator for their unbuffered modules (I'm pretty sure they always do in their registered modules).   Here's their "numbering scheme" -- note that it indicates a suffix of "S," "D," or "Q" to indicate the rank => but most of their part numbers (including those above) don't have ANY of these.  (    I'm optimistic that you're right, however, since you have single-rank sticks with a similar model number.

... as I've noted several times in discussions on EE, it's very frustrating that memory manufacturers don't make it MUCH clearer what the rank of their modules is.   That's probably the single biggest problem in terms of folks getting the "wrong" memory.

elmoredaniel - you started the question with the comment:  "... But thats exactly what I have plugged into it!!??" in reference to the message "... Due to chipset limitations this motherboard supports a maximum of 2GB and 4 ranks of memory."   ==> I presume you now understand that you did NOT have 4 ranks of memory plugged in (you had 8).     The reason you can't have that many ranks is straightforward -- 8 ranks of 8 chips is 64 chips => this means the address lines have 64 loads on them !!   That's far too much of a load for a stable address signal (or control signals, for that matter).   So the board simply disables the 2nd set of modules if the 1st set is dual rank.   By the way, updating to a later BIOS is not going to change this -- it's an electrical issue; not one that can be resolved by a change in the BIOS code.   Your board's not particularly "fussy" => it's just smart enough to not overload the memory controller's signaling drivers.

"... I bet you can't find single rank DIMMs of more than 256MB ..." ==>  I'm not a betting person;  but I'd be glad to bet you a nice new dual-core Intel Conroe system with 3TB of disk space, a nice nVidia 7900GTX 512mb graphics card, a Hauppauge dual-tuner PVR-500, a pair of Plextor DVD burners, 4GB of ECC RAM, a copy of Vista Ultimate, etc. that I can find you a single rank DIMM of 1GB (or even 2GB) capacity  :-)     I think you've already figured this out, however, ... so I won't clear off any desk space for my new system !!

You can either swap the dual-rank modules for single-rank modules; or buy 2 1GB modules of either single or dual rank  (note if you buy 2 dual-rank 1GB modules you won't be able to add more memory in the future).

Note:  ... if you want to listen to more about this topic, see item #9 here:  (the other topics may be of interest as well)

Appears that Kingston rank designation is not as straightforward as I thought.  Looks like the D designator is optional.

Memory designation has been a problem for years beginning with high density SDRAM modules.  I don't understand why manufacturers can't provide such critical information in their descriptions.  How much trouble is it to provide chip count and ranks?

I do have reasonable confidence that those particular Kingston modules are single rank.

Also wonder why Corsair would use a 16 chip configuration when 8 would do and should be less expensive to manufacture.
I'll let Gary collect the bet.  He's apparently in dire need of a decent PC to use ;-)
Gary CaseRetiredCommented:
Dalton -- so glad you recognize the needy :-)   Would you like my address so you can send a contribution?
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