CMC2GX1M2A400C3 Serial Number Question

[DonD]

I just bought 4GB of CMC2GX1M2A400C3 (CORSAIR XMS 2GB (2 x 1GB) 184-Pin DDR SDRAM DDR 400 (PC 3200) Desktop Memory) for my old Asus P4P800-E Deluxe motherboard. Since they are dual channel kits I thought I would use the serial number to differentiate between the 2 kits so that I could keep them together in the proper channels like I have done before.

 

I was surprised to see that both kits appeared to have the same serial number. All 4 sticks have the expected CMC2GX1M2A400C3 and the XMS3200 and timing, etc marking but I was surprised to see all 4 have the same number where I would have expected the 2 kits to have different serial numbers. All 4 sticks are marked 09520463.

 

Is this normal? Should the 2 kits be kept seperate or can they be freely mixed in the 4 slots?

 

Thanks,

 

Don

[RAM GUY]

That is the Lot code not the SN# and its the same the modules should all be from the same lot.

And with 4 modules DDR333 would be suggested at Cas 2.5-3-3-7 at 2.75 Volts.

[DonD]

Thanks for the reply. I thought they were s/n's. Then, can all 4 be freely be interchanged without messing up the dual channel feature?

 

Also, I don't understand your suggestion for running at the lower DDR333 frequency - the mobo and everything is rated at and had been running at DDR400. Is it because of having 4 modules?

 

Suggested timings and volts seem tto be running fine.

[RAM GUY]

If the system is stable then it should be no problem, however most systems using DDR1 would require a slower memory frequency when all four slots are filled.

[DonD]

OK - makes sense. One last question... :)

 

I've got the 4GB installed and running stable at DDR400/200mhz and the timings you suggested. I am very aware of the 32 bit OS limit and did not expect all 4GB to be seen by the OS (Win XP) and as expected see 2.87 GB - a little lower than I expected. Are there any utilities to get make more of the 4Gb available to the OS?

 

What really surprised me was that the BIOS only shows 2943 MB. I have the laest BIOS but as you would expect it's a few years old. The P4P800-E documentation says it'll handle 4GB. Any ideas?

 

I guess that was 2 questions - not one :)

[RAM GUY]

There are two parts to this one is the O.S. with a 32 Bit limitation and the other is the hardware. If the Chipset and CPU are only 32-Bit enabled then the chipset and or CPU will not see more than 32 Billion Bits of memory and the reason you see something less is because out of the 32 Billion has to come the other memory in your system like memory on the Video Card and Cache on your CPU and the chipset will sometimes reserve some for PCI caching as well.

 

However if you are using an AMD Athalon 64 CPU and chipset there maybe a setting in the BIOS to remap the memory but the O.S. will still not see all of the memory.