tl;dr version: latency / frequency = time, choose the one with the smallest numberOriginally Posted by billbartuska
Memory latency, or timings, like the number 10 in CL 10, are the length of time it takes the memory to complete a step in what it has to do. That "time" is measured in "clock ticks", ie CL 10 takes 10 clock ticks to complete before the memory can move on to it's next operation. The length of one clock tick is the speed at which the memory is running. 1800 MHz memory has a clock tick length of one 1,800,000,000th of a second (1,800,000,000 clock ticks per second), so the CL step takes 10 x 1/1,800,000,000 seconds.
A stick of memory always takes the same amount of time to complete it's CL step (or any other step) no matter what speed it is running.. If you run the above memory stick faster, say 2400 MHz, it still takes 10 x 1/1,800,000,000 seconds to complete the CL step, but each clock tick is now 1/2,400,000,000 of a second, so it now would take more clock ticks to complete the CL step. Namely, 24/18 times 10 (for CL step) or 13.3 clock ticks (10 times 24/18 clock ticks). But, alas, that has to be rounded to to CL 14 as memory can't use partial clock ticks..
So to compare different memory you compare the actual time it takes each one to complete what it has to do, Usually just calculating the length of time for the CL step for each will give you your answer.
(DDR, DDR2, DDR3, DDR4) if it ultimately has no effect on performance.Originally Posted by billbartuska
Anand:
In fact despite the development of new memory interfaces, the true latency for DRAM under default specifications has stayed roughly the same since DDR. As we make faster memory modules, the CAS Latency rises to keep higher frequency memory stable, but overall the true latency stays the same.
And when he benchmarks there are other things (memory controller. etc.) that effect the scores and show the slight differences he reports.
What you're forgetting is the Data Transfer Rate. Data goes to and from the 1066 memory faster, so even though the data is "managed" slower internally by the 1066 memory it gets to and from the motherboard faster.Originally Posted by Slink3Slyde
Quote:
(DDR, DDR2, DDR3, DDR4) if it ultimately has no effect on performance.Originally Posted by billbartuska
Anand:
In fact despite the development of new memory interfaces, the true latency for DRAM under default specifications has stayed roughly the same since DDR. As we make faster memory modules, the CAS Latency rises to keep higher frequency memory stable, but overall the true latency stays the same.
And when he benchmarks there are other things (memory controller. etc.) that effect the scores and show the slight differences he reports.
(CL/(Freq-in-MHZ) * 1000) = speed in ns
9/933*1000= 9.95ns
15/1066*1000 = 14.07
If 1866 C9 should be much faster then 2133 C15 RAM if you apply the formula. But in actual fact its a bit slower effectively as shown in most of Anands tests and in the games tested by Hard OCP on the same processor, taking the memory controller out of the equation.
Something else is going on behind the timings listed?
I apologize if I missed something in your post before its been a long day so its quite possible![]()
Overclockability of any memory depends on the ICs and PCB (brain) in the sticks. You can but DDR 1600 that will overclock 5% and you can buy DDR 1600 that will overclock 50%Originally Posted by Slink3Slyde
So as pertains to the OP, 2133mhz C15 DDR4 is slightly faster then 1866 C9 DDR3 overall because of the newer faster memory controller/ z170 chipset improvements, despite the RAM itself actually working slower?
I'm guessing then, the highest sort of speeds you would get from DDR3L @ 1.5 volts might be 2400 C10 at the very top end, if you wanted to run 24/7 closer to Skylake spec on DDR3L at 1.35-1.4 volts even less. So maybe something like DDR4 2666 C15 or 2800 C15/16 would probably roughly match that overall at another educated guess on a Skylake chip. Going by the numbers that Anand and H got.![]()
Based on that, slight deviation from the topic...
ICS as in ICs or 'integrated circuits'?Originally Posted by Slink3Slyde
I know, but most times you will need to add voltage I believe., I do have some experience overclocking RAM but I lack detailed technical knowledge to explain the why'sI was taking a stab based on the fact most current ddr 3 kits at 2133 and over need 1.65 volts at stock, I believe there are some expensive DDR3L kits that will do 2133 C10 at 1.35 volts, based on that 2666 24/7 might be possible I suppose. But l think at that point it's probably cheaper to buy DDR4 3200+ which would be faster for Skylake anyway.![]()
It depends on the reason for ops question really.
Edit: I think that Trident generally have better ICS then Ripjaws, and Ares is more budget then both I think.
ICs the actual RAM chips on the PCB, I think Trident is Gskills premium line. The trident kits probably have tighter lower timings as well.Originally Posted by Darkwizzie
ICS as in ICs or 'integrated circuits'?
Ram's a toughphie because it's hard to tell if an application wants more frequency or prefers a good mix of low latency as well... especially if that application is not used often or benchmarked often.
16gb 4000 C19 for like $210 now, prices have really dropped. Going to 4266 C19 costs $300 for only 8gb though. I calculated the performance index of 4000 C19 and 4266 C19 and 3200 C13, but at this point I think the performance index would be way off...