A few problems

Michael BlackHeart amdmiek at gmail.com
Mon Mar 18 21:35:49 UTC 2013

2013/3/18 Chuck Swiger <cswiger at mac.com>:
> Hi--
> On Mar 18, 2013, at 11:16 AM, Jeremy Chadwick wrote:
>>> You've got an Intel P45 northbridge controller which supports dual-channel mode, but that only works for DIMMs of the same size.  You might be able to get 6GB if you place the DIMMs in slots 1 and 2 instead of 1 & 3 or 2 & 4.  Otherwise, try getting another 4GB DIMM and using 4GB + 4GB instead.
>> Off-list:
>> Except that Michael said, re: his dmidecode output:
>>> As you see it says that in DIMM4 there's 4Gb module, but it's 2Gb
>>> actualy. It's a Kit of 2x2Gb.  BIOS says that there's only 4Gb but
>>> FreeBSD see 6Gb. I'll try later to switch modules into DIMM1 & DIMM3
>>> but I'm not expecting any difference.
>> So let's recap:
>> - DIMMs are operating in single-channel mode (vs. dual-channel)
> Are they?  (I didn't see info one way or the other, but perhaps off-list communication confirmed that.)
>> - DIMM2 claims to be 2GB
>> - DIMM4 claims to be 4GB
>> - Intel P45 supports up to 16GB RAM (4GB maximum per DIMM)
>> - OS is amd64
>> If he did have 4GB+2GB installed, since he's using amd64, ideally he
>> would be seeing FreeBSD report "avail memory = (around 6GB)", which
>> isn't the case.  So something isn't making sense here.
> Right.  If one DIMM really is 4GB, then putting them into slots 1 & 2 should make a difference; or just install only one at a time to double-check.
>> Possibly the SMBIOS/DMI data claims to have a 4GB DIMM, yet in actuality
>> chip-wise only has 2GB on it.  In which case, the SMBIOS/DMI data is
>> wrong, or the DIMM manufacturer is shady.
>> I would not be surprised if the user had two DIMMs bought at different
>> times (even if they're the same model), or that one is just manufactured
>> wrong/badly.
> Maybe.  If you put different sized DIMMs into slots paired up for dual-channel mode, IIRC that era of Intel chipsets would work in dual-channel mode using the smaller memory size.  That resembles the current situation rather closely-- ie, 6GB installed but only 4GB available.
> But I suppose it could be a DIMM which claims to be the wrong size in DMI info....
> Regards,
> --
> -Chuck

I checked out. It's a kit of 2x2Gb as I said before. And I moved them
to 1 and 3 slots and nothing changed. currently  do not have any DDR2
modules to make some more tests.
Here's proof: http://www.miekoff.ru/wp-content/uploads/P1020858.jpg

And for the record, I used this memory on two other motherboards, one
was running WinXP and another FreeBSD  8.3 and later 9.1. And all of
them reported about 4Gb installed. Just like BIOS does. So it seems to
me like some weird thing. On the one side it could be a FreeBSD's DMI
mis-interpretating. On the other side as far as I know Corssair do not
produce something, but just tunes and overclocks memory chips. And
because of the radiators I can't visually compare chips one of them
easily could be a 4Gb module locked to 2Gb or something like that.

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