Q: Is all RAM created equal?

Well, like most other PC components, all RAM are not created equal. For DDR400, you can find memory varying from - very fast modules supporting 2-2-2-5 timings (CAS-tRP-tRCD-tRAS) from Mushkin, Corsair, OCZ (for example), to relatively low-cost modules that aren't as favorable with the timings. Many DDR400 modules currently available require the use of CAS Latency = 2.5, but this is not the worst variant. Note that the CAS Latency parameter alone does not influence the memory subsystem speed too much. Two other parameters, namely tRP and tRCD, affect the results much more heavily. This is a curious fact, considering that many memory sellers usually draw the customer’s attention to the CAS Latency parameter, often without even mentioning the other ones. So, it's recommended that you note that modules with CL = 2.5 or 3 will not in all probability work with minimal trp & trcd settings.

Q: What Memory to buy?

Touchy subject for some. For others, RAM is RAM, right? Riiiiight!!!!

If you plan on overclocking, I can't stress this enough - YOU NEED HIGH QUALITY COMPONENTS!! I can't tell you how many times I've tried to help people out with overclocking their systems and come find out that the one problem was they have no-name PC2100 dimms stuffed in their slots. Ick. One thing I can say with certainty is that you should buy PC3200 at the minimum for any new system - AMD or Intel. Not only for overclocked systems but for the sake of performance in general. Depending on the brand there isn't really much of a price differential between quality PC2700 and PC3200, so get PC3200. Quality RAM is not always expensive, but expensive RAM is often quality.

However, buying much faster RAM, isn't always the best idea, especially for AMD chipsets. Overall, PC4000 and higher modules are not quite compatible with these motherboards. It is advisable to stick with lower latency PC3200 or PC3500 modules. Just above every PC3700+ memory have high latency timings. Consider that Fighter Jet A is your PC4000 memory and is built for super-fast speeds, but cannot maneuver as well as Fighter Jet B which is lower latency PC3200. In a dog fight on AMD terrain, Fighter Jet B will win because the terrain is mountainous and requires more maneuverability. Likewise, Fighter Jet A would have more of a chance in Intel terrain because on such a terrain speed matters more and maneuverability (or latency) isn't as important. But since, as discussed earlier, we can realistically use an async mode on Intel systems, it may well prove that doing so and using top quality PC3200 or PC3500 memory and their attendant lower latency will allow Fighter Jet B to triumph in most all cases.

Bottom line is, don't skimp on your RAM selection. You'll be kicking yourself later if you do. But just the same, don't assume that because a particular memory type is expensive it is also superior for your application.

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by Exit edited by FastEddie
last modified: 2004-02-08 18:38:37