Short Guide for buying RAM

ram (Custom)

Random Access memory (RAM) is the main memory of a PC where every thing is loaded before it can be processed. Everybody knows there are lots of processes running in the background than it appears. Applications nowadays are resource hungry, they demand like anything. So, your 1yr old PC will not win the battle with stone age tools. Either you upgrade core components or buy a new one. Buying a new PC is not feasible every time, so considerable performance gain can be achieved by addition of more RAM on every PC whose other components are not bottlenecking the system. (I mean don't expect a blazing fast computer if you have upgraded to 512MB RAM with a Celeron)

Type & Clock of RAM : First of all you need to know what type of RAM (SD, DDR, DDR2) your motherboard supports. Now it is time for you to decide how fast RAM you want and how fast your motherboard can support. Yes, I am talking of the bandwidth they can offer. You might have seen RAM sticks as DDR 333Mhz, DDR 400Mhz, DDR2 533Mhz etc. This clock (mhz) is your bandwidth factor. The more, the better. To know either look at the manual provided with your motherboard or do a little search on google with your motherboard model number. Now you are ready with what type and mhz of RAM you want.

Two things still left for consideration are the latency & dual channel.

Latency is the time delay only after which the data can be accessed in the RAM. So the less,the better. No need to go into the details of latency because low latency rams are 30% to 100% more costlier than high latency RAM. So you need not consider such details while buying RAM for your desktop PC. Just go for branded names like Kingston. They tend to perform better than others. If you tend to go deeper in the latency stuff, I recommend this link.

Dual Channel is like you are running two identical sticks in combined mode, doubling the data transfer rate. This feature needs to be supported by the motherboard. Just insert two identical sticks in same colored module and its done. If you want good performance, go for matched pairs that specially come in a single packaging specially for dual channel performance. They are little expensive from normal RAM sticks but worth it.

Note :

  • When running two sticks, the whole system will run at the lower clock out of the two supported. For example : 1 DDR2 533Mhz and 1 DDR2 667Mhz will run @ 533mhz if run together. i.e. One will underclock itself
  • Never try any incompatible stick in your motherboard. Although they might run well in some case but they can also smoke up your cabinet. For example: If your motherboard supports DDR2 upto 667mhz, don't try the 800mhz stick. Even if it runs then also it will underclock itself to 667mhz. So it will cost more and will give no performance gain. (Don't go with the vendor)
  • Buying RAM running greater than FSB is pointless. FSB is how fast data can be transferred between processor and RAM. There is no point of buying a 667mhz stick if your processor has a FSB of 533Mhz.

I hope you will learn something from this. Any queries, suggestions and comments are welcome. Do tell me how you like the article.

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  • Good article for all those who want to buy a new RAM and dont know the features. I too faced this problem of selecting a good RAM some time back.

    • I am Glad that you liked it.

  • Shankar

    HOw can we know about the fsb i hav got ?? nice article … lots of information … iam on the way of upgrading my pc … so timely read too

    • Welcome on my blog, Shankar. You can either refer to the stationary provided with your processor or do a little search online. Alternatively you can use softwares like Everest which can report details of your hardware. If you are in any other kind of confusion then leave a comment here. I will be glad to help you.

  • Nice article, thanks for the info!

  • McDee

    this article helped alot when buying more ram to upgrade my machines performance i wondered if u had one that told u about video cards and the whole pci,pci-e,agp thing im totally lost with that :shock:.

  • @Evan
    You are welcome
    Expect it in coming posts.

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  • awesome

  • faaiz

    I have a question. My laptop takes SDRAM, SO-DIMM socket, DDR266/333. I am looking for a 512Mb chip but can only get 256Mb. Is there any alternative I can use, maybe a faster FSB or something.

  • @govee
    Thanks man!
    You can’t use a faster speed RAM than what your motherboard supports. Also If you use a faster RAM stick with a slower one then the faster RAM will underclock its speed to run along with the smaller RAM.
    Since you are on SDRAM which is out of market, it might be hard for you to find what you want. You will even have to pay more for it.

  • Very helpful article – cheers!

  • Virgil Bell

    Hey Guy Thank You for the info it came at a very good time for me,I am still at the learning stage.I have a geforce 6100PM-M2 board which supports DDR2 800/667/553/400DDR2 SDRAM.This is not a factory built computer,it has 2 1gig sticks of kingston KVR533d2n4k2/2g installed, last night while surfing the net one stick went up in smoke the monitor went black,i shut it down to have a look,found the fried stick took it out,tried to restart computer and it did start.My question would be do you think it would be wise to try to repair this pc after such an issue? By the way i found your website by typing in google UP IN SMOKE…Thank You for the great article

  • Sikander Sattar

    we doing computer recycling branded desktop and servers.we are facing problem in matching RAM because we don’t know which RAM speed is requaired by motherboard.Can you supply any thing through which can identify make and model with matching RAM

  • You said “When running two sticks, the whole system will run at the lower clock out of the two supported. For example : 1 DDR2 533Mhz and 1 DDR2 667Mhz will run @ 533mhz if run together. i.e. One will underclock itself”

    Why it happens?

    • If the lower one is forced to run at a higher frequency, then it will get overheated whereas both will run fine on the lower frequency. So, stability may be the reason of underclocking here.

  • erlan

    hi ashfame, id like to ask help coz i have a desktop computer Intel PIII processor 500MHz and 192MB SDRam. Im not a techy person so how can i upgrade my SDRam? what would be the best MHz to buy? would it be ok to buy 256Mb coz im kinda tight on my budget? Please help…

    • It will be hard to find SDRAM these days and that too expensive because it was out of mainstream a long way back. Just take care of that fact that a higher speed stick will work equivalent to the lowest speed stick in your system. Hope that helps 🙂

  • Melaney

    Non-ECC unbuffered or ECC unbuffered need to be considered as well. I used your guide and ended up with ECC unbuffered ram because you didn’t tell me I needed to look at that. This ram is for servers and workstations. Most home pc’s need non-ECC memory.

    Unfortunately my system information (using a program called siw) doesn’t specify this about my ram either, nor does the information on the label of the ram stick. I went out of my way to buy the exact same thing as what I already have.

    Now my system won’t boot with the new ram and I don’t think they are going to let me return it because I ordered the wrong thing. 🙁

    • Well that’s something I can’t be blamed for. I explained everything I knew but you bought something which was not even intended for desktop computers.

  • nick

    i found your article to be very informative. i like that you outlined the questions a person should be asking instead of just saying “this is good, do this”.