I wrote this thread to 1. inform others of the traps I encountered
2. to whine about how some traps are created to advantage vendors but end up just making complexity that hurts everyone. The RAM market is not simple. There are several dimensions one needs to get right: - technology (eg. DDR4 vs DDR5) - socket (eg. DIMM vs SODIMM) - standard (eg. DDR4 is nailed down by JEDEC but XMP "goes beyond" that standard). This one really annoys me -- don't call it DDR4 and then headline claims rquiring XMP without calling that requirement out. - physical size (heat spreaders make some DIMMs too tall for my application; perhaps they can also become too thick) - ECC / no ECC. This one is easy: you never get ECC without paying for it, so it is usually clearly marked. But it is not always clear whether a computer supports ECC. Random Ryzen system support ECC (great!) but it depends on the motherboard and the vendors don't highlight this. - registered/unregistered. Only servers, with a large number of RAM sockets need this. You might accidentally buy such a system used / off lease. It is a bit mysterious. The reason is that each circuit has limited "fan-out"; registered memory boosts the amount of fan-out allowed. You might also find some old registered memory cheap and then find that you cannot use it. - latency. Lower is generally better. It is a bit complicated -- there are several latencies for a particular chip. I just look at the headline one. Marketing has made that complexity unnecessarily hard to navigate. Even a fairly knowledgeable consumer like me gets bitten by traps that should not be there. RAM is a commodity. You should not have to read spec sheets from manufacturers to discover if a module will work for you. You should be able to go to any vendor and easily see what RAM they offer that would work for you. Amazon isn't a bad way to buy memory. But it doesn't let you search for RAM of the type you need. Without selective search, there is a lot of slogging. And, as I've described, the listings are misleading. Other retailers are different but not clearly better. I've looked at Canada Computers, Memory Express, and NewEgg. ca.pcpartpicker.com doesn't get this completely right. A couple of RAM manufacturers have product selectors that help you a lot. Lennart pointed this out. But then you don't get the advantage of buying a commodity. --- Post to this mailing list talk@gtalug.org Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
