They tell us the speed of RAM …
RAM speed is a very easy parameter to obtain, since it always comes in both packages and labels in the memory modules themselves. Moreover, as long as it is installed it is also easy to know what speed they have with software like CPU-Z or Aida64 for example, and in the same description and in the numbers of many manufacturers we can find speed. For example:
DDR4 3200 (PC4 25600)
DDR4 tells us the memory generation, and the same number appears on the right side of the PC, explaining the same (DDR4 -> PC4). The next four digits indicate the average speed at Megahertz, which is more of a marketing strategy than anything else, developed by RAM manufacturers and OEM manufacturers. That number tells us that, in fact, it is data rate, estimated at megatransfers for a moment, or 106 Data transfer per second
In DDR memory, the clock speed is actually half the data rate (in our example, 1600 MHz), but since DDR by definition transmits data twice per clock cycle, the speed it works
In contrast, the PC number (for example, PC4 25600) shows the transfer rate but express it in megabytes per second (MB / s). If we multiply the data rate (in megatransfers) with the bandwidth of the I / O bus (64 bits on a modern motherboard), we can see the actual speed:
3200 megatransfers per second x 64 bits per transfer / 8 bits byte = 25,600 MB / s
Each number independently tells us how fast RAM is, both numbers give us the same information but in different ways. So what about timmings?
What is RAM memory?
What we've explained so far is to tell you that RAM timmings it is another way of showing their speed. This parameter to measure the latency between the normal operations that occur on DRAM chips, and we understand the delays between these operations. We can understand it as a kind of "waiting time", and the minimum time is set accordingly.
We measure RAM times in clock cycles RAM manufacturers are usually listed with four-digit groups separated by hyphens, such as CL16-18-18-38. As we talk about "waiting times," a lower number means faster, and your order is what you will tell us what they mean.
Start time: CAS Latency (CL)
The time it takes for RAM to respond to processor requests is CAS latency (CL), but it cannot be considered alone as there is a formula that converts CL time into nanoseconds and is based on the RAM transfer rate
(CL / Transfer Rate) x 2000
Because of this, slow RAM can have real low latency when it has low CL.
Second timer: TCRD
RAM modules use a design based on an address machine. The merging of rows and columns of this space indicates a specific memory address. TCRD measures the latency (delay, what you need) between inserting a new row into memory and accessing columns within it. We can assume that it's like the time it takes RAM to reach one of its addresses.
By the way, the time it took to get a little bit of information from the line was not working by TRCD + CL.
Third period: TRP
TRP means something like "line load time," and measures the latency involved to open a new line in memory. Technically, it measures the latency between issuing a preload command in an inactive line (or off), and an unlock command to open a different line. This number is almost always the same as before, because they are affected by the same things.
Season four: AFTER
It means "active time" and measures the minimum cycles the line must remain open in order for the data to be accurately recorded. Technically, it measures the latency between a sequential unlock command and a preload command execution on that single line, or the minimum time between opening and closing a line. For SDRAM modules, TRAS is the sum of TCRD + CL.
In conclusion: you should consider timmings
These latencies reduce the speed of RAM, but are set by the manufacturer's specifications (i.e., not physically limited). The RAM memory controller is the one that uses this access, which means that it can be flexible (if the motherboard allows it), and can gain extra performance if it overcompensates, adjusting these latencies in certain cycles.
We have explained what they are and what they weigh. They are parameters that, much like the speed the manufacturer tells us, tell us how fast RAM we have about it they are boundaries that we should be aware of.
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