Z420: Memory read error - DB parity error

[Robert2222]

Ooookay now I REALLY understood what you are referring to haha :)) It's a very subtle misunderstanding:

I said that columns E, F and G support my observation.

My observation is: "old modules in a channel with both slots loaded cause the error"

E = old module in a channel with both slots loaded => error

F = old module in a channel with both slots loaded => error

G = NO old modules in a channel with both slots loaded => NO error

Column G is a test which doesn't include any old modules, but since no error arises this column still supports my observation of "old modules in a channel with both slots loaded cause the error".

Summary: No error in 1+2 if it is new+new (that's column G in the old screenshot as well as in the new screenshot, hope you can see it soon).

[mdklassen]

Now, I can see your new table.

Parity error:

B 5 or 6      OLD NEW
E 1 or 2      OLD OLD
F 1 or 2      OLD NEW
H 5 or 6      OLD OLD
I 1 or 2      OLD OLD
L 5 or 6  NEW OLD
M 3 or 4      OLD NEW

You may have one of the  OLD  sticks that is "bad". 

You keep moving it to different slots.

Can you run MEMTEST with less than 4 sticks inserted? 

The vendor's statement is "for optimal performance, use 4 sticks", but is that an absolute requirement to use 4 sticks?

If the computer will run with "less", try the "old" RAM:

* OLD1 in 1, with OLD2 in 3

* OLD1 in 1, with OLD3 in 3

* OLD1 in 1, with OLD4 in 3

* OLD2 in 1, with OLD1 in 3

* OLD2 in 1, with OLD3 in 3

* OLD2 in 1, with OLD4 in 3

* OLD3 in 1, with OLD1 in 3

* OLD3 in 1, with OLD2 in 3

* OLD3 in 1, with OLD4 in 3

* OLD4 in 1, with OLD1 in 3

* OLD4 in 1, with OLD2 in 3

* OLD4 in 1, with OLD3 in 3

As it runs, MEMTEST occupies some of the RAM in slot 1.

So, that's why I have listed OLD1 in 1 with OLD2 in 3,

                                    and also OLD2 in 1 with OLD1 in 3 --

to be sure that "all" the RAM on each chip is tested.

[Robert2222]

If I put 2 old modules into slot 1 and 3 (2 x black), then those two channels are "half-filled" because I leave the according white slots empty. But I have already tested all old modules in a half-filled setup! That's column C. It shows that the old modules work perfectly fine when in a half-filled channel ...

How is it possible that these memory modules work perfectly fine in a 1-slot-channel but not in a 2-slot-channel?

The new memory modules are exactly the same and they work in a 2-slot-channel.

[mdklassen]

> If I put 2 old modules into slot 1 and 3 (2 x black), then those two channels are "half-filled" because I leave the according white slots empty.

Yes, that is what I suggested, namely to leave slots 4 through 8 "empty", and run MEMTEST, if your computer will run with only these 2 slots being populated.

Does your computer boot in this configuration?

What did MEMTEST reveal, for each of the combinations that I suggested?

Without actual "experimental" evidence, we can talk "theory" forever, without approaching a solution.

> But I have already tested all old modules in a half-filled setup!

> That's column C. It shows that the old modules work perfectly fine when in a half-filled channel ...

Yes, you clearly have run that "experiment".  Now, I am asking you to report the results of further "experiments".

> How is it possible that these memory modules work perfectly fine in a 1-slot-channel but not in a 2-slot-channel?

Those are two different configurations, and something "subtle" is faulty with your RAM, and the fault is exposed only in a specific configuration.

That's why I have asked you to try to run MEMTEST on exactly two sticks at a time, and to report your results.

[Robert2222]

Okay finally done with all the configurations of your last post. Result: ALL of them work!

Additionally I've also tested 1-3-6 loaded with OLD modules (but this time not with all permutations of the modules): works fine too.

EDIT: I think continuing this thread doesn't make much sense since nobody with fresh ideas wants to read 2 pages of posts. Maybe I will reopen a thread in the hardware section and describe the current status right at the start.

[mdklassen]

> Result: ALL of them work!

So, what configuration does not work?

Do you have a configuration, with all 8 sticks, that does work?

[kinofaya]

Hi, I have the same problem, did you find a solution ?