Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

My motherboard has four slots for RAM. Three of these contain identical StarRam 1Gb DDR2 667Mhz sticks, and the fourth had been unoccupied. I decided to buy a fourth stick for this slot, and since StarRam seems to have gone out of business I went for a Crucial 1Gb DDR2 667Mhz stick instead. I assumed this would be close enough, but since installing the new stick my computer boots and runs very slowly. The motherboard specs says it supports dual channel memory (the slots are colour-coded) and can handle up to 8Gb. There are options in the BIOS for changing the frequency and voltage of the memory, but I'm not sure what to change. Is there a way to make the new stick of RAM work with the existing memory?

share|improve this question
3  
Just a thought, but run a couple passes of memtest86 against your machine. Perhaps your new memory is bad? –  Zoredache Apr 18 '13 at 19:31
3  
remove the new stick of ram and use the machine. Then try removing one of the other 3, replacing it with the new one, then use it. This way you can test whether it is the increased capacity, or the RAM module itself which is (or isn't) causing an issue. Also: are you using a 32 bit OS or a 64 bit OS? –  horatio Apr 18 '13 at 19:46

1 Answer 1

A couple of ideas on why this is happening:

  • The clock latency ratings on the ram you bought and the ram you had may be different. Clock latency measures the number of processor ticks that the ram requires before the ram will respond. Typically you try to get a lower CL rating because higher numbers equal a slower computer. A CL of 1 or 2 is great for SDRAM, but DDR ram will probably have a rating of 2.5
  • Ram between manufactures is generally not a good idea. Just because the ram has the same speed does not mean it works or manufactured the same way. Funny but true.
  • If your computer is an I7, I have read before that installing ram in 3's is the most efficient method because of the on board memory manager and adding a 4th can slow your computer down. That may have been the reason the fourth was left unoccupied.

Check the color of your dim slots if three are the same color and one is different that is typically a tell tell sign that was the way it was intended. Hope this is helpful.

share|improve this answer
    
Thanks for the suggestions! I'm running 64 bit Windows 7, and the four slots on the motherboard are coloured as yellow, orange, yellow, orange. The two yellows and one of the oranges were filled with the old sticks, and the new stick went in the empty orange slot. The old and new RAM are both CL5. I'll try putting the new stick back in and running memtest. Thanks for your help –  fionacha Apr 20 '13 at 13:09

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.