I have a Compaq Presarion r4125CA laptop and want to upgrade the ram. I am schooled heavily in computer hardware and networking, but Notebook memory was never anything I was too interested in.... It currently runs 2 X 256 Infineon Unbuffered, Non-ECC, 8 Chip (2x4) 2.5-3-3-7 modules (PC 2700), running in single-channel mode. The laptop has 2 Northbridge controllers, an ATI RS480M and an AMD Hammer IMC. Everest says that the Northbridge can support DDR-200, 266, 333, and 400 both Single and Dual-Channel. First question.. why isn't it in Dual mode, the chips were made in the same batch... Second question is, what do I have to look for in purchasing new RAM. Is it true that, as the not-usually-very-bright futureshop salesman says, I absolutely must buy HP or other "HP Suggested" modules (At 3 times the price...)? or will any 8 Chip, PC 2700/3200 module work? Do i need matched pairs? or would it be ok with 1X1GB and 1X256MB in case I buy another 1GB later? I know I need matched pairs for Dual-Channel.. but beyond that.. can anyone help? Thanks..
Well, I'm not entirely sure the laptop is setup for dual-channel, and I don't believe that the mobile Athlon's support dual-channel memory functions. The A64 design incorporates the memory controller into the CPU itself, which is the major player in it's performance. You can put up to 2GB (2048MB) in the system, but I can't find anything indicating dual-channel memory has been incorporated.
You certainly do not *have* to buy HP modules. You can buy different brand modules but you might get conflicts between the two brands. Sometimes it happens when you mix and match brands in RAM. You don't need a matched pair.
