PC2-6400 notch different than PC2-3200

[Audiofight]

I have a Dell GX280 and it has 2 256MB PC2-3200 dimms installed in it.

I purchased 2 1GB PC2-6400 dimms to upgrade it.

However, when I tried to install the dimm, they wouldn't fit.

I visually compared the two dimms and the notch is off by a 1/4" if that. Maybe 2 pins off when I you hold the dimms one on top of the other.

I have been out of the loop on memory standards for a while now, but I thought all DDR2 memory was supposed to adhere to the same design, pin count and notch placement.

Any ideas?

 

[SunnyD]

You sure you bought the right ram?

 

[Blain]

PC-3200 is a DDR standard, but PC2-6400 is a DDR2 standard.
The Optiplex GX280 does use DDR2 memory.
Could the Optiplex MB have been replaced with an older model at some point?

Of course we will need to see pics of the memory labels on both sets of DIMMs. :sneaky:

 

[imagoon]

This may help:

http://en.wikipedia.org/wiki/File:Desktop_DDR_Memory_Comparison.svg

When it boots up, does it boot up and say GX280 on the screen? If I am remembering my Dell history correctly, the GX270 was DDR and the GX280 was DDR2 but the GX-270 board did bolt right in to the GX280 chassis. Esp in the "full size" tower cases.

 

[SunnyD]

PC-3200 is a DDR standard, but PC2-6400 is a DDR2 standard.
The Optiplex GX280 does use DDR2 memory.
Could the Optiplex MB have been replaced with an older model at some point?

Of course we will need to see pics of the memory labels on both sets of DIMMs. :sneaky:

The GX280 comes (came at least) stock from Dell with 2x256MB PC2-3200 (400MHz) DIMMs. Yes... PC2-3200 exists.

 

[Golgatha]

You absolutely sure you're inserting the chip in the right direction? DDR2 should all have the same notch spacing and pin count.

 

[imagoon]

Actually random thought (rare to see this mistake) but you didn't pick up DDR2 ECC or Registered DDR2 DIMM's did you? The notches are different for those compared to vanilla DDR2.

 

[Audiofight]

imagoon

That is what I am thinking....I either got ECC or Registered DIMMs. I couldn't find anything definitive in my 10 minutes of Googling this morning.

To address the other posts, thanks first off:

- yes, it does say GX280 when I boot it up.
- yes, the 2 x 256MB dimms are PC2-3200, DDR2

When I hold up the two dimms, back to back, the notch is only off by about 1/4". If I flip one of the dimms, then it is off by like 2-2 1/2".

Most likely, I picked up some ECC or Registered memory and that is my problem. Not a huge deal, I paid $15 for each 1 GB stick. Hopefully, I can resell it at a similar price and recoup.

 

[bamacre]

Actually random thought (rare to see this mistake) but you didn't pick up DDR2 ECC or Registered DDR2 DIMM's did you? The notches are different for those compared to vanilla DDR2.

Really? Odd because some systems, like the Dell Precision 380/390/T3400 can use both ECC and non-ECC DIMM's (just not at the same time).


Audiofight, what is the model number of your new memory modules?

 

[jjmIII]

Really? Odd because some systems, like the Dell Precision 380/390/T3400 can use both ECC and non-ECC DIMM's

I'm with you. I've NEVER heard of EEC memory having a different keyed slot than its non-ECC brother. I think he has something other than DDR2.

 

[Blain]

I'm with you. I've NEVER heard of EEC memory having a different keyed slot than its non-ECC brother.

I'm with you.
MBs that support ECC and non-ECC memory are keyed one way.

If you simply post good pictures of the labels on both DIMMs, the mystery will be solved...
Crank that camera down to Macro Mode and Post Those Pics!

 

[Emulex]

i've got some pc2-3200 ddr2 - it's real. real old! lol.


ecc and non-ecc fit the same slot. my wayback machine doesn't work at 7am so i can't remember why there was different ram. registered? fb-dimm?

 

[jacktesterson]

Isn't 3200 DDR? Not ddr2?

 

[Blain]

Ok, let's put this part of the thread to rest...
PC2-3200 DOES exist... Click Here!

Now if Audiofight would be so kind as to post those pictures I requested, we can end the mystery and stick a fork in this thread.

Of course we will need to see pics of the memory labels on both sets of DIMMs. :sneaky:

If you simply post good pictures of the labels on both DIMMs, the mystery will be solved...
Crank that camera down to Macro Mode and Post Those Pics!

 

[bamacre]

Yeah, I definitely remember DDR2 400mhz, it was the lowest clocked DDR2, came out around the time Intel had Pentium IV 500/600 series processors.

 

[imagoon]

Really? Odd because some systems, like the Dell Precision 380/390/T3400 can use both ECC and non-ECC DIMM's (just not at the same time).


Audiofight, what is the model number of your new memory modules?

I looked it up and apparently I am remembering SDRAM which did have a different notch depending.

 

[Audiofight]

Sorry to take so long getting some photos taken.

http://picasaweb.google.com/101826608483721344453/DDR2Memory?authkey=Gv1sRgCO-t4u-NkdW7Kw#

I took a picture of a stick of PC2-3200 ECC I had laying around handy. I didn't tear any memory out of my htpc, which is running standard PC2-3200. But, I did confirm that ECC doesn't make any difference. The ECC stick will seat on the motherboard.

The Samsung stick with the silver heat spreader on it is the problem child. I have 2 sticks like this.

Greg

 

[imagoon]

Sorry to take so long getting some photos taken.

http://picasaweb.google.com/101826608483721344453/DDR2Memory?authkey=Gv1sRgCO-t4u-NkdW7Kw#

I took a picture of a stick of PC2-3200 ECC I had laying around handy. I didn't tear any memory out of my htpc, which is running standard PC2-3200. But, I did confirm that ECC doesn't make any difference. The ECC stick will seat on the motherboard.

The Samsung stick with the silver heat spreader on it is the problem child. I have 2 sticks like this.

Greg

I am tearing my memory apart (and the web) trying to find the document. Notice how on the left side of the chip, the old chips are not notched but the samsungs are? For the life of me I cannot remember what that notch means yet but it was done to prevent installation in to certain boards. I *think* the 6400F = FB-DIMM (F = Fully Buffered) which not all computers supported and that notch was to prevent an FB-DIMM from mounting in a computer that specifically didn't support it. However computers that supported FB often could still run on unbuffered ram so the notch was made 'one way' on purpose.

Example:

http://www.simmtester.com/page/news/showpubnews.asp?num=113

The bottom chip is FB while the top is not.

When you stack the old and new chip on each other and align the center notch, do the dimms line up except for the 1/8 inch cuts on the left and right?

 

[Bryf50]

From wikipedia

FB-DIMMS have 240 pins and are the same total length as other DDR DIMMs but differ by having indents on both ends within the slot.

Looking at the Samsung sticks you can clearly see the indents in the slot. Looks like you got yourself some FB-DIMMS. The good news is that they usually sell for a nice amount more then standard Ram, so maybe you can make a little profit off the deal

 

[Blain]

Yep, the Samsung m395t2953ez4-ce76 is registered ECC memory. Unless your MB is a server board it won't work.

A picture is worth a thousand posts.

 

[bamacre]

This memory should work just fine in the GX280...
http://www.superbiiz.com/detail.php?name=D21G667KI