What do ddr2 numbers mean

If you want to use faster RAM, don't mix it with your older, slower modules. You can, in theory, mix RAM brands, but it isn't advisable. You run a greater chance of encountering a blue screen of death or other random crashes when you mix RAM brands or different RAM clock speeds. You will sometimes see RAM modules with a series of numbers, like These numbers are referred to as timings.

The lower the numbers, the quicker the RAM reacts to requests. The first number 9, in the example is the CAS latency. The CAS latency refers to the number of clock cycles it takes for data requested by the memory controller to become available to a data pin. Weird, right? With a CAS latency of 7 cycles, the total latency is 1. Even if it has a higher CAS of 9 cycles, the total latency is 1. That's why it's faster! For most people, capacity trumps clock speed and latency every time.

In most cases, timing and latency are the last points of consideration. ECC ram is used in servers where errors in mission-critical data could be disastrous. For example, personal or financial information is stored in RAM while manipulating a linked database. You can find out the total data rate of a RAM module by multiplying its frequency by eight. Long past are the days where "K ought to be enough for anybody. The average amount of installed RAM is increasing across all hardware types, too.

Operating systems have different specifications, too. Conversely, numerous Linux distributions work extremely well with smaller amounts of RAM.

If you find yourself with six Word documents open at any one time, can't bring yourself to close those 60 tabs in Google Chrome, you will probably want at least 8GB RAM. The same goes if you want to use a virtual machine. But if you keep utilities running in the background, with a mountain of browser tabs and everything else, you'll appreciate the extra RAM capacity.

A RAM upgrade is definitely one of the easiest ways to get an instant performance boost. However, before committing to an upgrade, check out these common myths and misconceptions regarding RAM. They'll help you make a better-informed decision about how much RAM you need for your system and whether an upgrade is the best option.

At this point, you're essentially a RAM expert, so it shouldn't feel overwhelming next time you attempt to buy more RAM or an entirely new system. Really, if you have the correct form factor and the corresponding RAM generation, you cannot go wrong. Timing and latency do play a role, but capacity is king. Combined, these provide superior reliability and endurance nearly equivalent to SLC, yet at a cost-effective price.

Reliable speeds and customized functions cater to the requirements of various embedded system applications. Featuring the USB 3. This enables the memory controller to know the exact clock cycle when the requested data will be ready, so the CPU no longer has to wait between memory accesses.

Effectively, it doubles the transfer rate without increasing the frequency of the clock. This is achieved by improved bus signal. They can make the memory control the refresh rate according to the temperature variation.

DDR4 adds four new Bank Groups technology. Each bank group has the feature of singlehanded operation. You have already accepted cookies, but you may still revoke your consent at any time. Please see more details at Cookie Statement.

Change Settings. The smaller the number, the faster the memory. The memory module portrayed in Figure 1 has timings, while the memory module portrayed in Figure 2 has timings. To understand them, bear in mind that the memory is internally organized as a matrix, where the data are stored at the intersection of the lines and columns.

Notice that not all motherboards allow you to change the memory timings. Also, some motherboards may not be able to run at very low timings, and they may configure your memory module to run at a higher timing setting because of this. Figure 3: Configuration of memory timings at the motherboard setup. When overclocking your memory, you may need to increase the memory timings in order to make the system run in a stable manner.

Here is where something very interesting happens. Due to the increased timings, the memory may achieve a lower performance, even though it is now configured to run at a higher clock rate, due to the latency that was introduced. That is another advantage of memory modules sold specifically for overclocking. The manufacturer, besides guaranteeing that your memory module will achieve the labeled clock rate, also guarantees that you will be able to keep the labeled timings up to the labeled clock.

Now we are going a step further as we will explain in detail each one of the memory timing parameters. It tells us how many clock cycles the memory will delay to return requested data. Thus, for two memory modules running at the same clock rate, the one with the lowest CL will be faster. Notice that the clock rate here is the real clock rate under which the memory module is running — i. In Figure 4, you can see how CL works. You can even calculate the time the memory delays until it starts delivering data.

The period of each clock cycle can be easily calculated through the formula:. Keep in mind that you need to use the real clock rate, which is half of the labeled clock rate. So, this DDR memory would delay So, while the first data would delay CL clock cycles to exit the memory, the next data would be delivered right after the prior data that has just come out from the memory, not having to wait for another CL cycle.

Each memory chip is organized internally as a matrix.