I have a memory stick that says 256MB,SDR DIMM,H on it, however it will not work in my computer. The other ones I have in both my computers say either PC100 or 133 on them. Can someone tell me what this memory stick is compatible with? Thank You for any help. Chuck

13 Years
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Last Post by Coconut Monkey

The 'H' in that identification most likely indicates that the memory chips on the module are manufactured by Hynix.

It's possibly just a BIOS identification problem. Try downloading and installing the latest BIOS update for your motherboard and see if that fixes things for you.

You haven't really provided enough information for a more specific answer than that.


If you don't know the megahertz of your RAM, it's easiest to count pins. 184 pins are DDR (double data rate) and 168 or fewer pins are SDR (single data rate). There are specific instances where this rule cannot apply. So, identify your RAM using http://www.memoryx.net/generic-memory.html

After you identify your RAM, check your motherboard (using the manual or going to manufacturer website and checking online docs) and see if it is compatible with that specific type.

If you still have a problem after this, it could be that the specific stick is bad...you can take this down to a computer store with a memory tester or wait until a computer show comes through (sometimes they have memory testers) and get that puppy verified.

I know I've had my share of bad RAM...especially my PC133 (168pin). I had 5 sticks go bad on me in a span of 6 months....but they had been used for many years and they weren't MICRON brand memory...all my micron and crucial sticks are still working. Anyways, sorry about my blabbering...hope this information helps you determine the problem. :)



How to determine the frequency of the module?

Again, the simplest way to determine if the module is PC66, PC100 or PC133, is by simply reading the last digit or two of the part number on the actual chip. Here are two examples, a PC100 module from Micron and a PC100 chip from Samsung.

As you can see from the red arrow, this Micron chip has a "-8" designation that identifies it as 100MHz bus and 10 nanosecond. As noted earlier, had this chip had a "-7" or "-7.5" designator, that would indicate it was a PC133 chip, and had it been "-10" it would be PC66. Even knowing this, should you be uncertain of the modules specifications, Micron makes it easy to verify them by providing a part number cross reference, which you can see by clicking this link.


larrenfitz, this question was originally posted early last year. Chances are the creator has long since moved on. Your post is helpful, but please refrain from resurrecting old threads again in future.

This topic has been dead for over six months. Start a new discussion instead.
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