The search ends here for some PC upgraders, as some machines simply can’t be upgraded. The above screenshots, for example, come from an old, DDR3-equipped notebook that doesn’t support modules of 8GB each and already has its two slots filled with 4GB memory modules. A key thing for starters: DDR3 is a sign of an older PC, and you can’t simply swap in DDR4 modules in their place. On both laptops and desktops, DDR3 and DDR4 memory are keyed differently from one another and are incompatible. But if you’re not getting this information from the manufacturer, there are other ways to figure it out.

Even though these two are completely different platforms, both support DDR4-3600 at a synchronized FCLK. AMD recommended DDR4-3200 at the time of the launch of the Ryzen 3000 Series, and buyers who can’t afford DDR4-3600 at reasonable timings (CAS 18 or lower) might wish to consider this less-expensive option. ▶ Intel Z390, H370, B360, and Z370 Chipset Motherboards (With 8th and 9th Generation CPUs) Yes, that's some in-the-weeds math. But this explains why in our lead example, DDR4-3600 CAS 20 (11ns) can underperform DDR4-3200 CAS 14 (8.75ns) in certain operations: It takes 2.25ns longer for DDR4-3600 CAS 20 to respond. Most memory buyers won’t get down to that level of granularity, but that explains why you can’t weigh just a single specification in assessing performance memory. Moreover, most of that gain can simply be achieved by moving from one rank per channel to two, something that you might accomplish by simply adding another two matched-spec modules to a machine that has two empty slots. So bear that in mind as you shop the sales. Each dual inline memory module (DIMM) has two 64-bit interfaces (one on each side) connected in series. Each interface supports one rank of memory, so that a single-sided module usually has one filled rank, and a double-sided module usually has both ranks filled. (Caveat alert: Though less common, some memory has through-paths, or “vias,” that connect both sides to a single interface.) Since the two sides of a dual-rank module are connected in series, one might not expect the added rank of memory ICs (integrated circuits, i.e. “chips”) to improve performance. This is where interleaving comes into play. Interleaving allows two different operations to occur simultaneously, such as accessing data on one rank while transferring data on the other. Man bekommt hier einen guten und günstigen Marken-Arbeitsspeicher. Ich habe mich für die 16GB Version entschieden, die ich in einem SFF-Rechner mit Debian benötige. Mir war weder die Geschwindigkeit, noch die Timings wichtig. Nur günstig und von einem renommierten Hersteller sollte er sein.DDR3 is the sign of a geriatric PC, and spending to the max on performance-minded RAM for a platform that is fast disappearing in the rearview mirror may be false economy. Most DDR3 motherboards supported at least DDR3-1600, with later examples such as the AMD 990FX and Intel Z97 often exceeding DDR3-2133 and DDR3-2800, respectively.

That leads to our general capacity guidelines. We recommend 16GB of main system memory for most users who want to multitask without incurring the above-mentioned slowdown, and 32GB for heavy multi-taskers or those running memory-hogging programs such as video editors. The memory controllers of most consumer processors support up to four ranks of memory per channel, which is why so many dual-channel boards have four slots and why so many quad-channel boards have eight. If every module used in these boards was dual-rank, the memory controller would be “full.”

When it comes to a PC component as opaque as system memory, the idea of value-for-money often gets put aside when considering the “best” choice for a performance machine. But there’s a big statement that should be made here: Most programs see very little gain from high-performance memory with elite specs, and even the most memory-impacted programs we’ve used have showed less than 6% performance gain in going from ordinary DDR4 to an optimized configuration. DDR4-3200 could be a better choice for users who can’t afford DDR4-3600 at CAS 18 or lower latency, though. And given the age of these platforms, even slower (and thus, cheaper) memory could be appropriate. Investing in premium RAM for a venerable PC may not make sense within your budget, especially if you think you might upgrade the whole system before long. The good news is a resurgence of AMD-compatible DDR4-2933 memory modules on the market following Intel’s addition of this speed to its 2020 desktop processor guidelines. Those who think that DDR4-2933 is unacceptably slow should dig a little deeper to find out what other people are running with the same motherboard and processor. Imitation can be far more than the greatest form of flattery—it can save you a heap of time and trouble! ▶ AMD X399 Chipset Motherboards (With First or Second Generation Ryzen Threadripper CPUs) One thing to remember is that most systems require a matched pair of modules to run dual-channel mode, or four matching modules to operate in quad-channel mode. While past platforms have occasionally allowed for mixed modes using different modules, those didn’t perform optimally. That doesn’t necessarily mean that you have to ditch an old pair of modules when a pair of empty slots are available, as we’ve had good experience adding a new matched pair to an old matched pair of the same data rate, but doing so may make XMP mode unworkable. We’ve even added 2x 8GB kits next to 2x 4GB kits without breaking dual-channel mode, creating a 24GB (12GB per-channel) configuration as 8GB-4GB-8GB-4GB, by simply leaving the board at default (non-XMP) settings. You’ll just want to make sure the matched pairs are inserted into the proper paired DIMM slots recommended by the motherboard maker. DDR4 was launched primarily at per-module capacities of 4GB to 16GB each, while DDR3 modules favored 1GB to 4GB capacities per module. The upper limits of these specifications were twice as high, but it took several years for 32GB DDR4 and 8GB DDR3 modules to reach the consumer market after the introduction of the memory type. Because of those delays, many older motherboards required a firmware update to support the bigger, later capacity. (As seen in the earlier “old Dell notebook” example, many platforms never got those updates.)