Yes there are other things in the sticks besides the speed and voltage. Each stick has its own little program call a SPDT. this is what the memory controller access. That is the main reason you should always upgrade your ram all at a time.
Even if you purchase one set now and then another set later on even if the sticks are the same model number they could have a different SPDT program in them.
I have been there. when i upped my current ram from four to eight I bought two more 2x2 gig sticks of the same memory, but in the time between the vendor (OCZ) had modified the SPDT program. I had to have them provide me with a flash SPDT that i could flash onto all four sticks to make them identical. Then and only then did my memory meet stated timing specs but also they all ran at 800mHz vice 667
Thanks for your explaination. Yes, all my RAM are of Kingston, with the same model number. The difference is that the first set of 2 x 2 GB RAM is of CL5, while the newer set is of CL6. Probably, the one year elapsed between the 2 purchases has caused the second set of RAM to have different SPDT.
So, how can I request flash SPDT from Kingston? Which flash SPDT should I use? The one from older CL5 RAM, or the one from newer CL6 RAM? Is there any risk in flashing the SPDT of the RAM, similar to the one for BIOS flashing?
Thanks for your information.
Not sure if Kingston will provide that service so your best bet is to contact them. The big thing is your nice CL5 ram will most likely end up at CL6.
There is the same risk as one would have with a bios update as what you are basicly doing is flashing the bios of the ram sticks.
Not necessarily, I just bought 8gb of 800Mhz ram for my XPS , 4x 2gb all the same speed/brand/model/latency etc. The bios detected it all but it shows up as 667Mhz. That's how I found this thread, I was wondering what the issue was.
What does CPUID say? Click on the memory tab and double the frequency reading.