Memory Misery

[ModestCargo]

I just bought a 512MB DIMM stick of PC133 SDRAM for my Pentium III machine. It runs at 500Mhz and is not overclocked. I bought the memory along with an ATI Radeon 7500 64MB video card.

Anyway, when I brought the memory home everything was going great. I opened up my PC, grounded myself and proceeded to install the video card. I hooked up the monitor, mouse and keyboard and turned it on. All was well, so I shut it off and disconnected it and installed the memory. I installed the 512MB strip beside my existing 128MB strip.

When I booted it up, I checked the System Properties, and the computer reported the memory as 384MB. Okay, so I went and reversed the order the memory was in. Same thing. Then I tried putting in just the 512MB strip. Same thing, 384MB.

I can't figure out why this would be happening. Any ideas?

 

[Reg]

If your RAM is reporting at 384MB, that means that your motherboard only supports up to 384MB of RAM. Thus, your system max is 256MB (DIMM0)+ 128MB (DIMM1). You will need a new motherboard to fix the problem.

 

[NetRyder]

Right. Most of the older Pentium III motherboards supported a maximum of 256MB memory modules. Because of this, your motherboard recognizes the 512MB DIMM as a 256MB module. Same is the case with mine. I can only use 256MB (double-sided) DIMMs, or anything lower in each slot, for a maximum of 1024MB.

 

[Zedric]

I had this problem yesterday with a computer, but it was 256 MB extra instead. The 256MB was single-sided and the old 128MB was double-sided. The computer only reported the 256MB as being 128. I guess getting double-sided would help?

 

[jumpy]

Originally posted by Zedric
I had this problem yesterday with a computer, but it was 256 MB extra instead. The 256MB was single-sided and the old 128MB was double-sided. The computer only reported the 256MB as being 128. I guess getting double-sided would help?

That is correct, a lot of older motherboards need the double sided low density ram modules to correctly identifiy the size of the ram, especially with modules > 256mb.

 

[ModestCargo]

On my previous post I said that when I installed the 512MB stip alone, it still reported as 384MB. So it is not recognizing the 512MB strip as a 256MB strip.

As for the theroy about the maximum on my motherboard being 384MB, when we bought our computer the guy that runs the shop told us we could put 1GB of memory into it. At the time, 512MB strips had just come out. I don't know if he was being entirely truthful or not, but I know the max is at least 512MB because we had the option of upgrading the memory to up to 512.

And our existing 128MB strip was single-sided.

Any other ideas?

 

[ModestCargo]

Aha! I looked at the motherboard manual, and first of all, it says it supports up to 512MB of memory. Second of all, I had been led to believe by the computer guy that the memory speed was PC133. But the manual clearly states that it supports PC100 and doesn't say anything about PC133. So I have to return the RAM and get some PC100. That should fix it, right?

 

[Krux]

ram typically is backwards compatible, but not forward. so if u put some pc133 in there and it could only take pc100 it would work at the slower speeds.

 

[GoNz0]

BIOS upgrade

 

[jumpy]

Originally posted by GoNz0
BIOS upgrade

BIOS upgrades don't fix chipset limitations

 

[ModestCargo]

So maybe my motherboard will only take 256MB strips. I upgraded my BIOS about 1-2 months ago. My motherboard is an Asus P2-99.

 

[Perris Calderon]

ya, my old box supported 512, but only with two 250 sticks.

I couldn't add one big stick, had to use two small ones

 

[Taurus]

Originally posted by ModestCargo
On my previous post I said that when I installed the 512MB stip alone, it still reported as 384MB. So it is not recognizing the 512MB strip as a 256MB strip.

that's what gets me.

 

[Perris Calderon]

well, I never upgraded my box, but I was led to believe at first that it could only handle 384 by hp...one 256, and one 128, but it couldn't handle two 256's

later, I was told the board could hold 2 256's, but hp said it wouldn't work.

that's probably your issue also