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512Mb PC133 installed, Only sees 256Mb

512Mb PC133 installed, Only sees 256Mb

512Mb PC133 installed, Only sees 256Mb

I added 512Mb PC133 64x64 SDRAM to my "Great Quality PC" (1.1GHz Celeron from Fry's).  The book says that it can take a 512 MB module but the system seems to only see half of it.  Could the memory be defective?
Other than that, the system works fine.

RE: 512Mb PC133 installed, Only sees 256Mb

Some computers have trouble seeing certain pc133 memory modules correctly. Search this forum, you'll find several threads on this subject.

RE: 512Mb PC133 installed, Only sees 256Mb

What's the make/model of the motherboard?

What's the name brand of the memory you're using?


"The secret to creativity is knowing how to hide your sources."
  - A. Einstein

RE: 512Mb PC133 installed, Only sees 256Mb

I could not find any part numbers on the mother board.
The back of the computer case did have the following info:
Behavior Tech Computers - Model 12-SS-M786

The 128Mb memory module that came with the computer had the following info on it:  A-Data PC133 CL3

The 512Mb memory module that I purchased has a blue metal shield on both sides and has the following info on it:
512Mb 64x64 DIMM PC133 SDRAM.
The package from Fry's has the following info:
64x64 OEM 16 Chip 512Mb SDRAM 168 PIN DIMM  Part#2662992

The handbook for the computer states:
You must use 168 pin, 3.3V unbuffered PC100 or PC133 memory modules.  You can install any size memory module from 32MB to 512MB, so the maximum memroy size is 2 x 512Mb = 1GB.

With both memory modules installed the total memory shows 376Mb.  The 512Mb module is installed closest to the CPU.


RE: 512Mb PC133 installed, Only sees 256Mb

We see this all the time, there is probably nothing wrong with the 512 module just that it isn't fully compatible with your motherboard, now comes the tricky bit, buying a 512 module that will recognise all it's capacity might be down to trial and error, companies like Crucial or Kingston may be able to sell you something that is more likely to work  and possibly change it for another type if the first module is unsuccessful, either way it's a pain.

Replying helps further our knowledge, without comment leaves us wondering.

RE: 512Mb PC133 installed, Only sees 256Mb

zooter - This is OEM from a AMD board plant. Fry's does not know that it might make a difference and apparently does not care. Sell it to someone with an AMD board for cost if they can test it first - it probably will work fine for them if they're not overclocking. Unfortunately, it will not work in most Intel CPU boards like yours. Either shows half the memory or is completely unrecognized.

Don't waste your time fighting with Fry - they've been peddeling this since last fall without changing the decription or warning Intel owners and must have had thousands of complaints to date. Seems to run fine on AMD, so I have no idea why they don't just change the description. It's a pretty good deal.

No idea if this is related to the other RAM problems on this forum - just know that I have picked up several sticks from unwary Fry shoppers who bought it for their Intel boards. I'm running it in several ASUS/AMD boards at spec and have had no problems. YMMV, of course.

RE: 512Mb PC133 installed, Only sees 256Mb

One last attempt I would suggest is to try the 512MB module by itself, taking the 128MB module out of the system.  Sometimes incompatibilities exist between modules and not necessarily the motherboard.

If that doesn't work, I would adhere to Dreamland's and paparazi's suggestions above.

Good luck!


"The secret to creativity is knowing how to hide your sources."
  - A. Einstein

RE: 512Mb PC133 installed, Only sees 256Mb

Thanks for the wealth of info.  I do have an older PIII-350 on an ASUS motherboard.  It came with a 128Mb PC133 memory module.  I will try it on that system to see if it works.  I will let you know what happens.


RE: 512Mb PC133 installed, Only sees 256Mb

I did try the 512Mb module by itself and it shows 247Mb (about half).

I tried the 512Mb module in the ASUS motherboard with the PII-350Mz processor and it only showed 128Mb.  After downloading the manual for it (P2B) it recommends only using PC100 memory up to 256Mb. The 128Mb PC133 memory that came with it worked okay.  Now I just remembered Dreamland's comment (ASUS/AMD).  My board is an ASUS with an Intel Processor.

I may keep it in the 1.1GHz Celeron system even though it only sees 256Mb.  Not sure if I want to wait in the return line at Fry's.

Thanks for all of your help.  I really appreciate it.


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