I tried to increase my ram by adding a second 512 ddr strip. As a test I ran Rosetta several times together with further programs so as to stress the memory. Each time it failed producing an invalid result . I ran the new memory alone and it works ok. Could the problem be an incompatibility between the old unit PMI(Pqi) and the new one - Kingston?

My computer is a P4 2.5GHz with 512 mb ram 133 MHz

Any ideas please?

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I tried to increase my ram by adding a second 512 ddr strip. As a test I ran Rosetta several times together with further programs so as to stress the memory. Each time it failed producing an invalid result . I ran the new memory alone and it works ok. Could the problem be an incompatibility between the old unit PMI(Pqi) and the new one - Kingston?

My computer is a P4 2.5GHz with 512 mb ram 133 MHz

Any ideas please?

both ar the same ddr thing like ddr2 and ddr3? could cause trouble with some mainboards.

the wrong type of memory wouldn't fit in the board.

I'd recommend you create a memtest CD and run that (it's always useful to have). Also, are the memory settings in the BIOS set to Auto? If not, you might want to reduce the timings. Post back if that doesn't make any sense to you!

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Thanks for those suggestions.

How do I set the memory to auto?

I ran both memtest86+ and I found similar errors for old, new and combined ram. I also ran memtest (windows) and it passed on both singles but failed on the combined. It said pair 71733072 does not store values correctly.

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there will probably be an option for it in the BIOS, but there also might not. If you can post a link to the manual for your motherboard, or the motherboard model number then we can have a look.

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The mother board is Matsonic

MS9147C

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I had the same problem a while ago with two sticks of ddr400, different

brands. The timmings where different and they would work on thier own

but not together, Ended up buying a matched pair of ddr400 512mb that

solved the problem. You can use cpuz to check the speed etc.

Pete.

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Thanks for that tip. I checked with cpuz and found that there were a number of differences in the cache latency test. I think the best option is to trade the new one in for a single 1 GB stick.

Evan

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you should be ok if you set the latency manually in the BIOS to the higher (i.e. higher latency) settings of the two sticks. The two sticks might also be running in dual-channel mode (different to DDR/Dual-Data Rate) depending on whether the motherboard supports it. Dual Channel has a reasonable (~5%) performance benefit on all computers prior to the Core2 architecture (where it appears to have little benefit).

HTH
Danny

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I tried to increase my ram by adding a second 512 ddr strip. As a test I ran Rosetta several times together with further programs so as to stress the memory. Each time it failed producing an invalid result . I ran the new memory alone and it works ok. Could the problem be an incompatibility between the old unit PMI(Pqi) and the new one - Kingston?

My computer is a P4 2.5GHz with 512 mb ram 133 MHz

Any ideas please?

The PMI and Kingston use different voltages, but your motherboard has to pick just one. Wrong voltage may allow it to work, but the ram will have CRC errors. Find out what voltage and CL speed your PMI ram is, and get a matching stick for it.

Problem solved. I traded in the new 512 strip for a 1 GB strip and all works well. Many thanks to all for their assistance.

Evan

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