How to choose ram memory correctly

To gain speed on the PC, an element of crucial importance is to increase the RAM of the machine. However, when we go to buy the memory of our computer, we find many brands and models available, so we are lost.

Index of contents

How to choose RAM correctly

Which model to choose? DDR2, DDR3, or DDR4? With what speed? Is there a difference between one model and another? This post was written precisely to explain the characteristics of each of these models, from the old SDR-SDRAM memories (which are still in use today) to the new DDR4.

We recommend reading the best RAM memory on the market

Before doing an upgrade on the mic by adding more memory, you need to know what DDR, DDR2, DDR3 and DDR4 are. These are types of SDRAM memory, which do synchronized work, which means they use a clock signal to synchronize their transfers.

What does DDR stand for?

DDR stands for Double Data Rate or Double Transfer Rate, and memories in this category transfer two data per clock pulse.

Due to this feature, these memories are labeled with twice the maximum actual clock at which they can work. For example, DDR2-800 memories work at 400 MHz, DDR2-1066 and DDR3-1066 memories work at 533 MHz, DDR3-1333 works at 666.6 MHz, and so on. So don't be surprised if programs like CPU-Z indicate a memory frequency level of half.

Memory is undoubtedly one of the components that has the greatest influence on the overall performance of the computer. This is responsible for temporarily storing the data, while the processor calculates and performs the tasks ordered by the user.

Generally, people think that only the amount of gigabytes that memory has will leave the mic faster, but little do they know that the clock (also called frequency) and latency in which the memory works does not make a difference in the performance of the memory. micro.

To try to avoid some of the problems of the constant loss of performance of the current machines, one of the most important and economic solutions is the purchase of more RAM memory for the equipment.

Memory types

Then we leave you the memories from the oldest to the most current. So we learn a little hardware archeology.

SDR-SDRAM memory

This was the first memory capable of working in sync with the motherboard cycles, with no wait times. This type of memory outperformed the older EDO (Extended Data Out) and FPM (Fast Page Mode) memories in its ability to divide memory modules into multiple banks, accommodating up to eight banks in a DIMM (Dual Inline Memory Module).

As the name itself says, they are capable of doing only one transfer per cycle, which may not seem like much today, but at the time when they were standard, everyone was proud to have modules with the name of “PC- 100 ”installed on the machine.

Even present in some equipment still today, they are very difficult to find for sale, since they are no longer manufactured.

DDR-SDRAM (Double Data Rate)

DDRs outperform SDRs in their ability to perform two transfers per cycle, which does not necessarily double the effective rate (due to initial access time), but they almost do.

This feature is possible thanks to the inclusion of additional circuits, responsible for reading / writing the data twice per cycle. With the exception of the modification, the tracks of both the memory modules and the base card remained unchanged, as well as the other features, which contributed to the low price and popularization of this model.

In hardware analysis programs like CPU-Z, the effective speed appears with half the actual value due to double transfer, so a DDR-400 model is going to be displayed as 200 MHz.

Even with encouragement to run the latest operating systems, DDR memories have left the scene for the DDR2 generation to arrive. It is still possible to find models for sale in specialized stores, but at a very high price.

DDR2 (Double Data Rate 2)

The data transfer rate per clock cycle doubled again, and DDR2 memories are capable of four transfers per cycle, while maintaining virtually the same initial access time, offering excellent results in applications requiring high amount of sequential reading, but for those who required only a few random accesses they took little advantage of that speed relative to DDR memories.

In the daily use of a computer, we use several types of applications with very different memory needs, which makes it difficult to observe large differences in performance in everyday tasks. Actually, several users who have purchased the motherboards with DDR2 socket were disappointed at the time, because in various tasks a DDR2-533 memory takes more time to respond than a DDR-400.

DDR2 modules are still for sale, and are capable of running modern operating systems without bottlenecks and quite smoothly.

This model supports the 'Dual Channel' function, which allows two identical modules installed in the machine to obtain a performance gain of up to 25%.

DDR3 (Double Data Rate 3)

The DDR2-1066 model was the last to be officially recognized by JEDEC (Joint Electron Device Enginnering Council), the certifying entity of the memories, and was already operating at very high frequencies (266 MHz multiplied by 4).

From that point on, as with processors, increasing the base clock speed exponentially increased power consumption and heat generation, so the most effective solution was to double the number of transfers per cycle again.

This simple change in transfer circuits makes it possible to create operating memories at 2133 MHz (266 MHz multiplied by 8), which is an impressive speed even by today's standards.

These new modules also brought a signal calibration system, reducing latency without compromising performance.

The union of higher transfer speeds and shorter access times still caters to both the home and high-performance computer markets today, and the sheer number of compatible chipsets and platforms contributed to a drastic drop in prices.

DDR4 (Double Data Rate 4)

This new type of memory brings interesting resources, such as a lower voltage (therefore a lower power consumption), the initial speeds of 2133 MHz and reaching up to 4266 MHz, in addition to a shorter access time.

Samsung was the first of the big companies to push the new standard, by validating a 40nm specimen in 2009 and bringing the first specimens to light in 2011, manufactured using 30nm technology. Right now it is the flagship of RAM, albeit with high hopes of seeing higher performance with DDR5 and DDR6 in the coming years.

The Importance of RAM

RAM stands for 'Random Access Memory', as it acts as a kind of buffer between the hard drive and the CPU. Hard drives work well when working with large blocks of data, but they are extremely slow to jump from sector to sector or switch between writing and reading. If a CPU were to process the data directly on the hard drive, there would be an impressive bottleneck.

That is why we need RAM. Having more RAM means that the frequency with which you will have to keep your computer reading or looking for data on the hard disk will be less.

Faster memory means that the CPU will be able to get what it needs faster. But of course this still doesn't answer how much RAM is going to be needed, or the circumstances where faster RAM helps the most.

How much RAM is needed?

What you do with your computer is what determines whether or not it is worth having more RAM.

2 GB of RAM: the minimum of the minimums

Basic daily tasks like browsing the internet, editing documents, and even watching some HD videos can be done by a system with just 2GB of RAM, as long as you don't try to do everything at the same time.

Things are going to work, but a little more RAM would make such a big jump in performance that at current prices jumping to 4GB is a super worth investment. Except on netbooks, it is difficult to find a machine that only comes with 2 GB currently on the market.

4 GB - the correct starting point

When it comes to the balance between cost and performance, 4GB is becoming acceptable, at least for now. In ordinary daily tasks, very rarely will you even get to use all of this. Unless you're in the habit of leaving dozens of flash-filled tabs open in Chrome.

Advanced gaming systems work well with 4GB of memory. You can also use Photoshop or heavy video editors without problems. Unless you're engaged in professional high-resolution image editing or industrial-scale 3D modeling, 4GB is more than acceptable. Although I always recommend having a minimum of 8GB on your computer

8 GB: recommended to work

Unless you are using your computer in some very specific way that you actually use all 8 GB of RAM, you can disable the pagefile (memory paging) entirely. This will give you a subtle boost in performance, improve system security, and less strain on your hard drive.

However, if you usually work all day with your computer and you need to leave a large number of programs open, this amount of RAM will help you in your tasks.

Tips for choosing the right RAM

All these points are essential to choose a suitable memory for your equipment, which you will have to take into account when buying it.

Know the type of RAM

When adding more memory to the computer, the user must be aware of some important factors. The first of them is the knowledge of the RAM model used by the motherboard, because you must buy a memory module that follows the same specification as the motherboard.

Otherwise, the new module or motherboard will most likely not work. For example, a DDR3 memory will not work on a machine that only supports DDR2.

There are specific programs to discover what hardware is installed on your machine. For example, for Windows, the PC Wizard application performs this task. In Linux, this information can be obtained through the command: "$ sudo lshw".

Do not mix different brands

It is also not recommended to mix memories of different brands and frequencies, since a motherboard with different modules can work irregularly, decreasing the performance of the system. Therefore, just try to combine modules of the same model and manufacturer on your machine.

In the case of users who use their PC to play games, before replacing memory, a full evaluation of the machine is necessary to determine if adding RAM is really going to have the expected effect. In most cases, players are required to purchase a new PC to run the newest games on the market.

Consider speed and latency

Latency is the time that the memory controller must wait for a data request to enter and its effective delivery. It is also known as the CAS Latency (Column Address Strobe) or timing.

This number is expressed in clock pulses. For example, a CL3 memory means that the memory controller needs to wait three clock pulses until the data is supplied after its request. With a CL5 memory, the memory controller will have to wait longer: five clock pulses. Therefore, you should always search for memory modules with the lowest possible latency.

We already know how much memory is needed for a computer, now we just need to know how fast it has to be. Thus, to have the best results, it must be as fast as the base card allows.

Memory modules are also valued in timings, which are usually a sequence of numbers, such as 9-9-9-24. The most useful of these numbers is the first, known as 'CAS Latency'. This is the number of clock cycles that RAM takes to access a column of data (the smaller, the better) and, in conjunction with the speed of RAM, can be used to calculate the response time. The formula is:

1000 * CAS ——————— (Speed ​​of RAM ÷ 2)

This account will give you the response time in nanoseconds. So, for example, a Kingston DDR3-1866 HyperX memory module has CAS 11 latency, while G.Skill DDR3-1600 memory has a latency of just 6.

In this case, the least fast RAM is G.Skill, since it responds in just 7.5 ns, while HyperX, which has a much higher speed discounting latency, takes 11.7 ns.

This means that the G.Skill memory will be faster when it comes to random access, but the higher HyperX memory clock speed offers more bandwidth, making it the best for batch operations.

Normally speaking, you'll want to choose the clock speed first, and then look at CAS latency as the tiebreaker. Keep in mind that shorter times mean higher prices. For example, the difference between a CAS of 7 versus a CAS of 8 is almost negligible.

DDR3 memories have higher latencies than DDR2 memories, and DDR2s have higher latencies than DDR memories. This means that DDR3 memories take more clock pulses to start transferring data than DDR2 memories.

Know the voltage supported by the motherboard

Memory voltages are very important when it comes to compatibility. The standard for DDR3 memory is 1.5V, but many performance-oriented Dimm modules require higher voltages to reach higher clocks and lower latencies. This can cause problems because not all motherboards can recognize the correct voltage for these memories and will supply the standard 1.5V.

If that's not enough to keep the memory stable, the system won't boot even for you to get to the BIOS and manually increase the voltage. Make sure you know the capabilities of the motherboard before buying RAM memory modules with special voltage needs.

Operating system limitations

32-bit operating systems have an important limitation: they can only support up to 4 GB of memory. You may think that everything is fine, since 4 GB is currently the ideal amount of RAM in most cases, but the limitation is total memory, not just RAM.

Some chunks of RAM are reserved for PCI and ACPI peripherals, and video memory is also included in this sum. With graphics cards that take a while… for example, those that fit up to 2 GB of video memory, it may happen that you have 4 GB of RAM installed in your system, but with less than 2 GB in real use. Therefore, it is recommended that you use a 64-bit version of your operating system.

Dual-Channel

Realizing that the computers were a little slow and that just increasing the frequency would not be enough, the solution was to change the memory controller of the motherboards, or even the processors. The memories must work in pairs to be able to use Dual Channel technology, that is, it is necessary to install two memory modules on the motherboard.

Dual Channel is the resource that allows the chipset or processor to communicate with two memory channels simultaneously. The memories work simultaneously and provide twice the width of the bus data. Common to DDR memories is working with 64-bit quantity, but with the Dual Channel feature, this value is doubled and found at 128 bits.

Slots quantity

These are the inputs that are available for memory modules. Keep this in mind so as not to buy an amount above what the motherboard supports. There are several programs that you can find on the internet that will point to the compatibility of the base card and also the number of slots that are available.

The vast majority of motherboards have Dual Channel technology, which allows the system to have a better working performance in terms of parity. In other words, two 4 GB modules would work better than only one 8 GB.

The brand and manufacturer

The memory brand is synonymous with quality and durability, since the more valuable the manufacturer, the greater the guarantee that the hardware purchased will work with better performance. Basically, it is possible to divide them into two large groups: the known and generic brands.

Among the main companies that manufacture memories, we can mention G.Skill, Kingston and Corsair, each offering its own characteristics. Normally, they tend to have a good quality, being recommended for computers that need a lot of performance, such as machines intended for games.

The generic RAM memories are cheaper compared to the original ones, however, they are of doubtful origin, and may compromise the overall performance of the PC. For this reason, the equipment for navigation, in most cases, is already sufficient.

• Corsair: is the one with the highest price and the most features. For some processors, such as those made by Intel, Corsair develops specialized modules to further improve transfer rates. This brand is especially recommended for gamers, who need maximum performance on their machines. Samsung: memory that has a good quality / price ratio, since it also works efficiently. Its main use is recommended for work equipment that requires good hardware. Kingston: In its original form, it is an excellent memory. However, it suffers from the "Powered By" problem, which means that Kingston sells its chipset (the hardware part) for generic brands. This makes users buy generic modules thinking they are from this company. Therefore, its use is intended for lighter machines. Patriot: these memories are more geared for those looking for performance, there are many models with excellent performance. G.Skill: this brand tends to innovate a lot in terms of frequency, it has already produced memories with more than 4400 MHZ, whose voltages are usually 1.2v to 1.65v. The prices are not low, but like some other brands it is worth it for the performance its memories offer.

conclusion

Often times when the computer is slow, this can be fixed by updating the device's RAM. Before making the purchase of RAM, you should pay attention to certain details that may be essential, as we have seen in this article.

WE RECOMMEND YOU How to know how much RAM I can install on my PC

In short, it is the profile of each user that will point out how much memory is necessary for the computer, whether for basic tasks, for professional use or for playing.

MORE DOUBTS? ENTER OUR FORUM AND ASK US