Memory addition not adding up

sol1109

Posts: 44   +2
System:
Motherboard = Gigabyte GA-EP45C-UD3R
OS = Win 7 - 64 bit
Memory = CRUCIAL CT2KIT12864AA1067 (2-1GB DDR2 8500)

I Purchased a new set of DDR2 DIMMs, CRUCIAL CT2KIT25664AA1067 (2-2GB DDR2 8500). Original memory was installed in slots DDR2_1 and DDR2_3 per manual for a total of 2GB. I installed the new memory in slots DDR2_2 and DDR2_4. This should create two matched sets for a total of 6GB. On boot the PC started rebooting at windows load.

I removed the two 1GB modules and installed the new 2GB modules one at a time and then together in the DDR2_1 and DDR2_3 slots. Each time the PC booted fine. I then installed the original 1GB DIMMs in slots DDR2_2 and DDR2_4, (the reverse of my first attempt) This time the PC would reboot without completing POST. The BIOS had a continuous series of beeps between boots.

Both sets of DIMMs are the same except for memory size, ( DDR2 PC2-8500 • CL=7 • Unbuffered • NON-ECC • DDR2-1066 • 1.8V). What have I missed?
 
Might be possible that they aren't compatible?

Given the price of DDR2 RAM these days, I'd recommend that you just sell the smaller RAM sticks, and not worry about this problem.

4GB should be enough for your system, and you wouldn't notice the extra 2GB. Unless you heavily multitask with RAM intensive programs or something.
 
So in addition to having the same timing and product family of DIMMs I should have the same capacity? I thought as long as I had a matched set in channel 1 and another matched set in channel 2 I would be fine, especially since both sets work by themselves.

As CMH suggested I have stuck with the new 4GB setup and put the original 2GB into storage for now.
 
System:
Motherboard = Gigabyte GA-EP45C-UD3R
OS = Win 7 - 64 bit
Memory = CRUCIAL CT2KIT12864AA1067 (2-1GB DDR2 8500)

I Purchased a new set of DDR2 DIMMs, CRUCIAL CT2KIT25664AA1067 (2-2GB DDR2 8500). Original memory was installed in slots DDR2_1 and DDR2_3 per manual for a total of 2GB. I installed the new memory in slots DDR2_2 and DDR2_4. This should create two matched sets for a total of 6GB. On boot the PC started rebooting at windows load.

I removed the two 1GB modules and installed the new 2GB modules one at a time and then together in the DDR2_1 and DDR2_3 slots. Each time the PC booted fine. I then installed the original 1GB DIMMs in slots DDR2_2 and DDR2_4, (the reverse of my first attempt) This time the PC would reboot without completing POST. The BIOS had a continuous series of beeps between boots.

Both sets of DIMMs are the same except for memory size, ( DDR2 PC2-8500 • CL=7 • Unbuffered • NON-ECC • DDR2-1066 • 1.8V). What have I missed?


I had the same thing, ie reboot at windows load. it sounds a similar story.
I used to have 256 meg in slot 1 and gig in slot 2 and the PC ram fine.
Then (because of another memory issue) I was reading the manual and deduced
I should have my memory in slots 1 and 3 not 1 and 2.
Anyway I did that and I got the reboots on windows startup (not on post).

Anyway basically what I am saying is try putting your 1 gig sticks in slots 1 and 2.
If that works (worse case is a reboot I think) the try your 2 gig sticks in slots 3 and 4.

I just say that because when I had different sized memory wher they should have been matched I got the reboots on the windows start up.

So it's worth a try, although, like yours my matched channels were 1 and 3.

AS has been said selling your 1 gig sticks sounds like a good option, I don't know what you are doing but well if you can't manage on 4 gigs...... I do OK on 1.25 gig at the moment!!!

Also the 1 gig stick are best sold now rather than later, you will get a better price now.
 
If you don't put them in matched channels, the RAM will not work in dual channel mode.

Reports indicate that dual channel doesn't exactly boost performance by a whole lot, but given that just about every motherboard now comes with dual channel RAM as standard, there must be more to it than meets the eye. Not to mention that socket 1366 processors may now be put with TRIPLE channel RAM.
 
If you don't put them in matched channels, the RAM will not work in dual channel mode.

Reports indicate that dual channel doesn't exactly boost performance by a whole lot, but given that just about every motherboard now comes with dual channel RAM as standard, there must be more to it than meets the eye. Not to mention that socket 1366 processors may now be put with TRIPLE channel RAM.

Well I put a 256meg and a 1 gig stick in as a matched pair and I had the same problem
that it ran until windows started so it looks like the same issue.


I tested my ram and it was reported twice as fast by memtest,
Granted memtest is not 'real life' but it did look very impresive to see the memory benchmark double!!
 
Thanks pjamme for the link. I tried memory off that list from OCZ when I first purchased the motherboard and had nothing but problems even after getting a replacement motherboard. Gigabyte would not stand behind the list so I decided to go with the selector on the Crucial web site.

I am happy with the 4Gig so I will just put the old mem in storage with the OCZ sticks.
 
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