Double the memory=much, much slower computer

Hey all,

Had a friend come to me with this computer problem. I would really appreciate any input you have on this.

The situation:
Friend decides to upgrade Dell XPS T500 P3 500mhz computer from 128 meg of factory installed ram to 256 total by purchasing a second 128 stick from Dell. AFter RAM is installed the system acts like it only has 32 megs of RAM in it even though it recognizes the RAM on bootup and in Windows 98 SE. Original stick was Toshiba and new stick is Kingston, both PC133 but neither state their CL.

What I have done so far:
Went over with my own RAM to prove it was a bad stick and needed to be RMA'ed. Pulled both sticks and put a known good Crucial 256 PC133 CL2 in the system after verifying the initial problem only to see the system act just as slow with a single 256. The system's hard drive goes nuts when there is 256 in the system. I assigned iryual memory settings and even set the computer to be a "network server" with no change. Hard drive has over 20 gigs of free space and it was just defragmented and scandisked. Put a single 128 back in the system, either old or new, and the system runs much faster and you don't really hear anything out of the hard drive. I updated the BIOS to the latest revision, reset BIOS to defaults and turned back on some normal stuff, PnP, USB, LPT settings nothing else really with no change to the system. I had to go after that because I had other plans that evening.

Other ideas:
Possibly loading the latest chipset drivers but dell didn't have anything from what I could see so I was just going to go to Intel and download the BX chipset drivers which i what should be on that mainboard, I'll double check before I do that ofcourse and maybe install the latest drivers for the video card. Other than that maybe reload from scratch which of course no one ever wants to do so I may just put a spare hard drive in there to test with.

I am thoroughly confused on this one, if anyone has experience with such a situation or anything else to try please help!!!

Thank you,
Tony

PS Sorry for the long post

Try to find a BIOS update.

According to Dell, only 100mhz DIMM's are supported. You need PC100 - PC133 is not backward compatible to PC100. If Dell sold him PC133, or installed PC133 in the system originally, they should replace it. Take a look at the memory advisor at crucial. Although they do list 128mb pc133 as compatible, everything else listed is pc100. I've got an hp at home w/ a bx board that's in the same boat.

You are not stating which flavor of Windows is in use. I know of some boards with Intel Chipsets, which do not handle RAM above 128MB properly when running Win9X platforms. HDD just runs and runs.

If you DO end up reloading this machine, try Win2K, and after you finish loading, just for grins, try more RAM. Sure was an eye-opener for me. If you have a spare HDD, you can do this with another drive, bypassing the OS drive belonging to the customer, and at least you will know if it is a chipset/OS issue.

HTH

I've updated the BIOS to the latest revision. I never thought about the PC133 deal, I'll try some 100 when I am able to get the computer again next week. It is Windows 98 SE. He doesn't have a copy of 2k so that is not possible right now. I thought the same thing about how much RAM 98 can handle since I don't think I ever installed that amount of RAM in a 9X system before that I can remeber. I'll do a more thorough search on MS's KB when I get a chance. I am currently on vacation so my responses may be a little slow to questions...

Thanks a lot all,
Tony

I run 384mb ram in 9x systems, seems to be the sweet spot. Anything over 128 is fine.

I would look at the cas settings. PC133 is backward compatible in that it will run at pc100 speeds, but ONLY if the motherboard likes it.

I have a lovely stick of samsung 256 that will only run in one machine.... but a a couple of other noname generics will run in all machines... go figure.

The more I think of it, the more I don't see this having anything to do with the PC133 rating because the system will run fine with either 128 by itself. It's when you put a total of 256 in the system that it goes to crap, whether it's two 128's or a single 256.

Tony

Quote:

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Originally Posted by thirdfey

The more I think of it, the more I don't see this having anything to do with the PC133 rating because the system will run fine with either 128 by itself. It's when you put a total of 256 in the system that it goes to crap, whether it's two 128's or a single 256.

Tony

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Ram compatibility has become a real beeeeaaaatch. PC133 is "supposed" to be downward compatible, but isn't!!! At least most times. What does your mb maker recommend? What does www.crucial.com recommend? If what is supposed to work with your board does not work...well guess what??

Quote:

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Originally Posted by thirdfey

The more I think of it, the more I don't see this having anything to do with the PC133 rating because the system will run fine with either 128 by itself. It's when you put a total of 256 in the system that it goes to crap, whether it's two 128's or a single 256.Tony

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Some time you must trick dell motherboards, you can try using the two farthest slots, from the CPU, fill the slots one at a time, from the last to the first (3, 2, 1,). To see if it will run, or try filling all three slots with the same value memory.

Dells are almost as finicky as Gateways. :flame:

The other thing is I have not found one dell that likes Kingston value-Ram yet. :eek2:

:) Dual sided Modules seam to work better than a single sided Module :rolleyes:

Quote:

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Originally Posted by hudsonsmith

..You need PC100 - PC133 is not backward compatible to PC100..

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Yeah it is, you just have to have a bios that lets you trim back its timings right ;) & slow it down .. you are right in the fact that not all bioses let you do this, so yeah many machines can't do it, but in 'principle' I think not ;)

Dell sold him this as 'suitable' methinks he should give them some 'stress' about it .. if they think like me 'in principle' maybe they are too dumb to know the limits of their own machines bioses, it wouldn't surprise me one bit ..

Since both sticks work 'seperate' ok it seems to me that it can't get the timing differences straight over the different banks/slots & that dell ought to know that !

I'm pretty sure Dell bios will not let you adjust the memory timings. And the list of things Dell "ought" to know seems to grow longer daily.

Quote:

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Originally Posted by hudsonsmith

I'm pretty sure Dell bios will not let you adjust the memory timings. And the list of things Dell "ought" to know seems to grow longer daily.

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I'll bow to your experience on that ;) - I was just correcting 'in principle' :)

There are tools you can get to make bios adjustments, but I'm not even gonna name them (unless thirdfey wants to be tinkering for weeks ?) .. methinks you should/'really have to' take it up with them ! You need to be absoluely certain of all the ras & cas & refresh settings that are suitable & available & somehow I just can't see that being available in any mannuals & you need to cut to the chase & be talking to third line support about this .. some numpty on the help desk won't know ;)

What would be much better is the same stuff as you've got already .. or something 'really' compatible & they should know .. but I'm not gonna hold my breath ..

I have a dell here at the moment... only thing is bios about the ram is the fact that it has some.

So dell put a stick of PC133 in the system when the system was ordered and when therir customer orders a second stick of RAM they send the customer another stick of PC133?

Tony

Ram is strange stuff. I know of situations where a matched pair of ram sticks would NOT function together, but replace one stick with a noname and it was fine.... you may just have a mismatch, nothing you can do except shove different makes of sticks in there and try it.