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Crash after installing more Ram

Recently I upgraded my Dell XPS 120 (Pentium) to Pentium/MMX by using Powerleap's adaptor. It works fine with original 32mb (EDO). However, when I pulled out 2*8mb from and added 2*32mb EDO chips into slot 1&2 (80mb total), the system became very unstable. The error message indicated "programs perform illegal operation" appeared frequently. When I pulled out the rest of 2*8mb chips, left only 2*32mb onboard, the system would crash immediately after windows start.
However, when I replaced the 233 MHz with the original 120 CPU, the system worked fine.
Does this crash have something to do with BIOS Ram setting, such as memory wait state adjustment?
As Dell doesn't offer option to change this setting, what's the best way to make this adjustment?

Thank you for your advice.

Weimin

jlove1

It's probably a memory timing issue.
I don't know exactly what BIOS that your DELL has, but You can tell, whenever the computer boots, it'll say what kind of BIOS it has (AMI,AWARD,PHOENIX, etc.).

You can download the appropraite program from the page

It will let you access ALL the settings (ram timings, etc) in your bios.

rmarotta

weimin,
If the proposed answer does not solve your problem, simply re-open the question so that other experts can provide a solution for you.
What is the complete model number of your Dell?
Ralph

weimin

ASKER

It's a Dell XPS120c, with latest BIOS A06. Since this upgrade, I tried different brands of EDO Ram, putting them into different slots, and making different memory combinations. What surprises me is how sensitive they are to the new Pentium 233/MMx chip. The following is the result:
Pair 1 = 2*8mb original Ram
Pair 2 = 2*8mb generic Ram
Pair 3 = 2*32mb generic Ram
Pair 4 = 2*32mb OEM Ram

Slot 1&2 Slot 3&4 Total Ram Symptom NortinIS Bench
1, Pair 1 Pair 2 32 normal 56
2, Pair 1 Pair 3 80 Crash
3, Pair 1 Pair 4 80 Normal 46
4, Pair 3 64 Crash
5, Pair 4 64 Crash
6, Pair 3 Pair 1 80 Crash
7, Pair 4 Pair 1 80 Crash

It seems that I have only 2 options: either have less memory or have more memory with lower performance.
Dell tech support said that the 32mb should be put into slot 1&2 to improve performance. But I can't.
If I adjust memory timing, that is, increase the wait state, the performance will also be suffered.
The other thing I'm thinking is the size of L2 cache. This system has only 256K Pipeline cache installed. Is 256K only supposed to handle up to 64mb Ram? If it is, will the extra Ram which is not cached cause system crash?

I'd appreciate all your suggestions and advice.

Weimin

jlove1

what was wrong with the suggested answer? You can use the utility on the page I suggested to access the internal workings of your BIOS, thus changing the RAM timings.

weimin

ASKER

I appreciated your suggestion. However, there is no information on your reply that I can download that program.

Weimin

rmarotta

weimin,
In some motherboard designs, the use of RAM in excess of 64Mb causes performance to be degraded.
Is it possible to add more cache memory to your motherboard?
Ralph

ASKER CERTIFIED SOLUTION

rmarotta

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