We want to buy some server RAM (one piece, 8GB). But since the price grows exponentially we are thinking about buying regular PC RAM instead. Would this cause problems? Should we go ahead and buy the PC RAM?
The PC RAM is built for speed.
However, the Server RAM is optimized for crash resistance and loss of data.
The Server RAM usually contains ECC – Error Correcting Code. ECC also commonly called EDAC protected memory helps correct parity errors which makes ECC RAM less vulnerable to loss of data, data corruption and possibility of a crash. This makes Server RAM much safer. Due to the implementation of ECC, these RAMs are a bit slower than their PC counterparts and are pretty expensive too.
On the other hand, PC RAMs are manufactured for speed. These RAMs neither have ECC or are they compatible. Hence PC RAMs are faster than a Server RAM however, prone to crash or data loss when subjected to higher amounts of stress. ECC Memory would not be supported by PC Motherboards and the BIOS. Hence it is advisable to check if your motherboard and BIOS supports one if you are planning to make your desktop into a server.
Higher price should reflect better quality.
While the speed of the memory and whether it supports real error detection/correction should be specified in the part number, what you can't tell is the quality of the product - how much QA/testing there is, the quality of the components used. Typically you won't see a difference until a few months or more of usage.
There's no magic answer as to what to buy - even high quality components can fail on day one. Its just a balancing act between your budget, the architecture of your application (loding a single webserver out of a farm of 20 should have very small impact - but losing all your database capacity is different) and the actual hardware it is implemented on.
You should also think about how it affects any current warranty's for the hardware.