Blaat schreef op donderdag 16 maart 2017 @ 13:48:
Wat ik trouwens niet snap is dat er hier qua geheugensnelheid erg op frequentie wordt gefocust. Dit terwijl timings ook niet onbelangrijk zijn.
Als inderdaad in de praktijk blijkt dat ryzen veel profijt heeft van snel geheugen maar moeite heeft met hoge frequenties kan je dan niet gewoon geheugen pakken met super strakke timings?
Of maak ik hier een denkfout?
Timings zijn belangrijk en lager is in principe beter.
Maar de CAS latency is geen complete aanduiding van de Latency omdat ook de clock cycle time een rol speelt. Zodra je dat er in betrekt spreek je van True Latency.
Omdat door de historie heen de True latency vrij constant is, is normaal gesproken de DDR Speed een grotere factor.
Althans zo begrijp ik het.
Wikipedia: CAS latency :
"Because modern DRAM modules' CAS latencies are specified in clock ticks instead of time, when comparing latencies at different clock speeds, latencies must be translated into absolute times to make a fair comparison; a higher numerical CAS latency may still be a shorter absolute-time latency if the clock is faster. However, it is important to note that the manufacturer-specified CAS latency typically assumes the specified clock rate, so underclocking a memory module may also allow for a lower CAS latency to be set.
Double data rate RAM operates using two transfers per clock cycle. The transfer rate is typically quoted by manufacturers, instead of the clock rate, which is half of the transfer rate for DDR modules. Because the CAS latency is specified in clock cycles, and not transfer ticks (which occur on both the positive and negative edge of the clock), it is important to ensure it is the clock rate that is being used to compute CAS latency times, and not the doubled transfer rate.
Crucial explains: "Speed vs Latency": Why CAS latency isn't an accurate measure of memory performance
"Based on in-depth engineering analysis and extensive testing in the Crucial Performance Lab,
the answer to this classic question is speed. In general, as speeds have increased, true latencies have remained approximately the same, meaning faster speeds enable you to achieve a higher level of performance. True latencies haven't necessarily increased, just CAS latencies. And CL ratings are an inaccurate, and often misleading, indicator of true latency (and memory) performance.
Tip: In de Pricewatch staan de true latencies en kun je hier op sorteren.
[
Voor 85% gewijzigd door
Help!!!! op 16-03-2017 18:16
]