can't add more memory

[xtole]

so many problem with my pc. i have 192mb of sdram memory, pc100. ihave another sdram memory here,256mb, pc133. can i install the latter memory on my system.my system manufacturer is intel, system model is whitney system cr board.help me please!

[TechZ]

Welcome to the forums xtole

Its better not to mix memory. SO if u have to choose and ur board can support it, go for the 256mb.

[robertdwhite]

I have a similar related problem and you may have answered it above but will ask for clarification. I have several older computers that call for the outdated pc100 sdram. I would like to replace it with the PC133 of the same form factor Ie. 168 pin is this doable?

[hudsonsmith]

Depends on the motherboard. PC133 is not backwards compatible with PC100. Some will accept both, but many will not. Need to know make/model of motherboard and/or computer to tell.

[robertdwhite]

Depends on the motherboard. PC133 is not backwards compatible with PC100. Some will accept both, but many will not. Need to know make/model of motherboard and/or computer to tell.

The computer is a compaq presario EZ2200.

[hudsonsmith]

Compaq only mentions PC100, but Crucial says it will accept PC133 http://www.crucial.com/store/listpar...200.&submit=Go
You may need to install a bios update to use the latter. This one lists some fixes to memory compatibility: http://h10025.www1.hp.com/ewfrf/wc/s...wareitem=33642

[TripleRLtd]

Depends on the motherboard. PC133 is not backwards compatible with PC100. Some will accept both, but many will not. Need to know make/model of motherboard and/or computer to tell.

Truthfully, according to the Intel specs PC133 is supposed to be backwards compatible, but often is not. Especially with "name brand" machines. I have to keep pc100 ram in stock just for those occasions.
http://www.dewassoc.com/performance/..._memory.htm#14

[robertdwhite]

Thanks so much for the info guys. I am going to do some experimenting. I have some various pieces of memory laying around. I will try some swaps and see what I get. I will let you know.

[Ruslan]

Truthfully, according to the Intel specs PC133 is supposed to be backwards compatible, but often is not. Especially with "name brand" machines.

That's true and not... Why not? Because it doesn't say anything about motherboard's chipset. And the true is - many of an older Intel chipsets (actually - every of PI-PIII chipsets, including i815) did not support high density memory, only low density. In other words, you will need memory stick with at least 8 chips per side for each 128Mb... 256MB stick must be 16-chips double-sided... It doesn't matter, PC100 or PC133, if you have only 66-100Mhz CPU...
Only VIA chipsets beginning from VIA693A and newer can support high density memory (still with limitations)... It is not a first time that issue is beeing discussed, by the way...

[xtole]

my board doesn't boot if i choose the 256mb pc133.. whats the problem now?is it my board which doesn't support such type of memory..well the memory in my system is 192mb pc100

[Ruslan]

I will quote myself:

In other words, you will need memory stick with at least 8 chips per side for each 128Mb... 256MB stick must be 16-chips double-sided...

So, how's your 256Mb memory stick look like?
And who is the manufacturer? What's written on chips?

[robertdwhite]

My experience on this one is that Ruslan was exactly correct. The 133 card cause a complete loss of funtionality in the video. I think the computer booted but all that appearewd on the screen was giberish. When I removed the 133 ccard and inserted the 100 low density everything seemed to work fine. I was not able to add as much ram as I wanted but at least it worked well.

[TripleRLtd]

As Rus states, yes, there are chipset limitations as well, (thanks again rus), which is why the Crucial ram that hudson referred to may work. Plus, they guarantee it, if I am not mistaken, so you can't go wrong.

[robertdwhite]

One more thing you may want to try. In the machine I was working on a Compaq EZ200 I found that when isnstalling the 133 card it was slot sensitive. The 2200 has two slots. It came with a 64 meg 100 card in slot one. When it put the 128 meg 133 card in slot two it did not work. However, when I put the 133 card in the first slot and the 100 in the second slot they both worked fine. The cards used were both low density ie double sided, I did not have an opportunity to check if the machine would have accepted a high density card. Hope this helps