RAM problem

[eddta]

I'm having a bit of a strange problem. I got some new RAM for christmas from my brother (yay) 2, 1Gb sticks to add to the 2 I already have installed. They are both corsair and exactly the same sticks of RAM in every way. When I first booted up it worked fine and I shut down. The next time I booted up it wouldn't do anything the fans started up and then the CPU fan went up to max speed. I then removed the new sticks and it worked fine. I then tried each stick in at different times and it works 3 in at a time. I don't know what's going on.

[Lee H]

Are they the same revision number on the side?

Sometimes different revisions of the same sticks are made with different chips, due to the scope of supply and in some cases they can have different voltage requirements.

Not only this, but when all the memory slots on a motherboard are populated, you sometimes need to adjust the voltage by increasing it slightly in order to get the system to boot.

[eddta]

They are different revisions so I'll try to change the voltages. Thanks for the help.

[eddta]

I tried to change the voltages but no luck. But I did find out the sets are different. The original pair are TWIN2X2048-6400C4 - 2GB (2x1GB) Corsair TwinX XMS2, DDR2 PC2-6400 (800), 240 Pins, Non-ECC Unbuffered, CAS 4-4-4-12 and the new set are TWIN2X2048-6400 - 2GB (2x1GB) Corsair TwinX XMS2, DDR2 PC2-6400 (800), 240 Pins, Non-ECC Unbuffered, CAS 5-5-5-18. However I have tried running one of each at the same time and it works properly as well as 3 sticks of either kind at the same time. It is only a problem when all the slots are filled.

[peterb]

Most manufacturers source the actual memory chips from the cheapest at the time - its a competitive market! Two chips from different mfrs - apparantly with the same spec, may differ slightly in actual operation, so when you mix the pairs, the timings may be slightly different, andf the memory bus just can't cope. In your case, the second pair are different - and again while they are fine onthere own, when mixed with a pair with different characteristics, the system can't cope. If you can RMA the second set and get something nearer the original pair, you may get away with it, but there is still a (smaller) risk that the replacements will be different source and you MAY run into problems. But the only way to tell is to try it and see.

If the second pair came from Scan, they are normally very good at replacing incompatible memory (although you will have to wait while it is retested by them) - other suppliers may vary. Talk to them first.

[eddta]

Thanks for the help. It's probably my only option.

[ANZAC_ELITE]

Northbridge, VTT and MCH voltages will probably need to be raised with all four DIMMS populated.

Have you run Memtest86+ on the modules to make sure none are faulty?

I had a lot of trouble with my old Asus P5E3 running four DIMMS, thankfully my current Black Ops has no such problem.