The reason it is not optimal is because you are mixing DIMMs within a bank. The system supports tri-channel memory. It does this by spreading a bank of memory across 3 channels. Here are how the banks are set up:
DIMM 0 - 1,2,3 DIMM 1 - 4
For an optimal configuration the DIMMs in slots 1,2,3 shoud be identical. In older systems that do not support flexible memory configuration the DIMMs in slots 2,3 would be disabled. Since this system supports flexible memory configurations it will allow the DIMMs to stay, but gives the non-optimal error.
If you mix memory in this system you can only have 1 unlike DIMM installed for an optimal configuration. The optimal configuration that uses the maximum memory for the DIMMs you have available would be:
8GB - 1,2 4GB - 4
The best non-optimal configuration would be:
8GB - 1,2 4GB - 3,4
That configuration will still give you errors, but is better than the current configuration.
I also see that mixing capacities of ram is supported as long as each channel has an identical configuration.
This doesn't mean that you have to have identical DIMM modules in the channels. It means that the channels must be populated the same. Here is an example:
DIMM 0 = slots 1,2,3 DIMM 1 = slots 4,5,6
Chanel 0 = 1,4 Channel 1 = 2,5 Channel 2 = 3,6
You can have DIMMs of different rank, speed, and capacity mixed across the channels, but you cannot have different configurations. For instance, in this configuration if you populated slots 1,2 with DIMMs then the only valid configuration for DIMM 1 would be populating a single DIMM in slot 4(If the system did not require DIMMs to be installed in pairs) or 2 DIMMs in slots 4,5. You could not populate a DIMM in slot 6 since the first slot(3) in the channel(2) is not populated.
The channel population rule basically means that you cannot populate the second slot in a channel if the first slot is not populated. In your system slot 1 and 4 are in channel 0. All other channels only have a single slot assigned to each memory controller. As long as you have a DIMM in slot 1 you can populate slot 4.
Memory population rules can be very confusing. If you have any more questions let me know.
Just want to be clear - If I took out all of my 4GB DIMMs, I could use 3 8gb quad rank DIMMs to get 24GB?
Yes, you could even install 4 for 32GB. If the DIMMs are mixed then quad rank DIMMs are only supported in slots 1,2,3. If they are all the same you can populate all 4 slots with them.
Also, I would put them in slots 1,2,3 just like the 4 4GB were originally from dell?
If you are only installing 3x8GB quad rank DIMMs, yes that would be the optimal configuration.
Also, I put the two 8GB DIMMs in slots 1,2 and the 4GB in slot 4 like you said for the optimal setting, but I am getting an error still. Seems to want A1-A3 all the same, even though A1,A2 are and I skipped A3
It may give a non-optimal error no matter how you populate them. Optimizer mode requires all DIMMs to be identical for optimal configuration. Any configuration with mixed memory is considered non-optimal.
Check to make sure the memory mode is set to Optimizer, and check to make sure the slot numbering is correct. The slots are not numbered 1-4 starting from the left. The slots are from left to right 4,1,2,3.
The reason it is not optimal is because you are mixing DIMMs within a bank. The system supports tri-channel memory. It does this by spreading a bank of memory across 3 channels. Here are how the banks are set up:
DIMM 0 - 1,2,3 DIMM 1 - 4
For an optimal configuration the DIMMs in slots 1,2,3 shoud be identical. In older systems that do not support flexible memory configuration the DIMMs in slots 2,3 would be disabled. Since this system supports flexible memory configurations it will allow the DIMMs to stay, but gives the non-optimal error.
If you mix memory in this system you can only have 1 unlike DIMM installed for an optimal configuration. The optimal configuration that uses the maximum memory for the DIMMs you have available would be:
8GB - 1,2 4GB - 4
The best non-optimal configuration would be:
8GB - 1,2 4GB - 3,4
That configuration will still give you errors, but is better than the current configuration.
[quote user="APITech"]I also see that mixing capacities of ram is supported as long as each channel has an identical configuration.
This doesn't mean that you have to have identical DIMM modules in the channels. It means that the channels must be populated the same. Here is an example:
DIMM 0 = slots 1,2,3 DIMM 1 = slots 4,5,6
Chanel 0 = 1,4 Channel 1 = 2,5 Channel 2 = 3,6
You can have DIMMs of different rank, speed, and capacity mixed across the channels, but you cannot have different configurations. For instance, in this configuration if you populated slots 1,2 with DIMMs then the only valid configuration for DIMM 1 would be populating a single DIMM in slot 4(If the system did not require DIMMs to be installed in pairs) or 2 DIMMs in slots 4,5. You could not populate a DIMM in slot 6 since the first slot(3) in the channel(2) is not populated.
The channel population rule basically means that you cannot populate the second slot in a channel if the first slot is not populated. In your system slot 1 and 4 are in channel 0. All other channels only have a single slot assigned to each memory controller. As long as you have a DIMM iMemory population rules can be very confusing. If you have any more questions let me know.
Thanks
[/quote]
wow thank you so much! I think I get it now!! few quick questions:
so skipping channel 2 (slot 3) isn't a big deal?
if I want more than 20gb, can I purchase one more 8gb (identical) and use those in slots 1,2,3 and put a 4 in slot 4 for an optimal config? I definately want an optimal configuration!
Just want to be clear - If I took out all of my 4GB DIMMs, I could use 3 8gb quad rank DIMMs to get 24GB?
Also, I would put them in slots 1,2,3 just like the 4 4GB were originally from dell?
Also, I put the two 8GB DIMMs in slots 1,2 and the 4GB in slot 4 like you said for the optimal setting, but I am getting an error still. Seems to want A1-A3 all the same, even though A1,A2 are and I skipped A3
Daniel, I have a similar question, I purchased 8 2R x 8 8GB chips to put into my T410 with dual processors, 4 chips for each processor. When I boot the server displays a DIMM mismatch error for slots A1, A2 and A3. The system still shows 64GB of total memory available. Will the system function okay like this?
One other possibility is a failed DIMM. If one of the DIMMs is failed or disabled for some reason then that would cause a mismatch with it's matching DIMM in the other lane. Also, it could cause a population error if there were DIMMs populated in higher channels than the channel the failed DIMM is in.
Daniel, I have a similar question, I purchased 8 2R x 8 8GB chips to put into my T410 with dual processors, 4 chips for each processor. When I boot the server displays a DIMM mismatch error for slots A1, A2 and A3. The system still shows 64GB of total memory available. Will the system function okay like this?
It sounds like it is working. If it is giving a mismatch error then the system thinks that all of the memory is not the same. Either you are using non-validated memory that the system is not able to fully communicate with or not all of the DIMMs are the same.
No, but most BIOS have the option to disable stop on error. If you turn that off then the error will still show up, but it will not make you press F1 to continue boot.
Daniel, I checked the dimms in BIOS and Server Administrator and all show up as okay with total memory list at 64GB. Windows 2012 is also recognizing the 64GB. I physically checked the dimms and they are all the same size and speed. Anyway to turn the boot warning off?
Daniel My
10 Elder
•
6.2K Posts
1
March 8th, 2014 13:00
Hello
The reason it is not optimal is because you are mixing DIMMs within a bank. The system supports tri-channel memory. It does this by spreading a bank of memory across 3 channels. Here are how the banks are set up:
DIMM 0 - 1,2,3
DIMM 1 - 4
For an optimal configuration the DIMMs in slots 1,2,3 shoud be identical. In older systems that do not support flexible memory configuration the DIMMs in slots 2,3 would be disabled. Since this system supports flexible memory configurations it will allow the DIMMs to stay, but gives the non-optimal error.
If you mix memory in this system you can only have 1 unlike DIMM installed for an optimal configuration. The optimal configuration that uses the maximum memory for the DIMMs you have available would be:
8GB - 1,2
4GB - 4
The best non-optimal configuration would be:
8GB - 1,2
4GB - 3,4
That configuration will still give you errors, but is better than the current configuration.
This doesn't mean that you have to have identical DIMM modules in the channels. It means that the channels must be populated the same. Here is an example:
DIMM 0 = slots 1,2,3
DIMM 1 = slots 4,5,6
Chanel 0 = 1,4
Channel 1 = 2,5
Channel 2 = 3,6
You can have DIMMs of different rank, speed, and capacity mixed across the channels, but you cannot have different configurations. For instance, in this configuration if you populated slots 1,2 with DIMMs then the only valid configuration for DIMM 1 would be populating a single DIMM in slot 4(If the system did not require DIMMs to be installed in pairs) or 2 DIMMs in slots 4,5. You could not populate a DIMM in slot 6 since the first slot(3) in the channel(2) is not populated.
The channel population rule basically means that you cannot populate the second slot in a channel if the first slot is not populated. In your system slot 1 and 4 are in channel 0. All other channels only have a single slot assigned to each memory controller. As long as you have a DIMM in slot 1 you can populate slot 4.
Memory population rules can be very confusing. If you have any more questions let me know.
Thanks
Daniel My
10 Elder
•
6.2K Posts
0
March 9th, 2014 12:00
Yes, you could even install 4 for 32GB. If the DIMMs are mixed then quad rank DIMMs are only supported in slots 1,2,3. If they are all the same you can populate all 4 slots with them.
If you are only installing 3x8GB quad rank DIMMs, yes that would be the optimal configuration.
It may give a non-optimal error no matter how you populate them. Optimizer mode requires all DIMMs to be identical for optimal configuration. Any configuration with mixed memory is considered non-optimal.
Check to make sure the memory mode is set to Optimizer, and check to make sure the slot numbering is correct. The slots are not numbered 1-4 starting from the left. The slots are from left to right 4,1,2,3.
Thanks
Daniel My
10 Elder
•
6.2K Posts
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March 8th, 2014 14:00
No, it is the last slot in the bank and can go unused without issue.
Yes
Thanks
APITech
4 Posts
0
March 8th, 2014 14:00
This doesn't mean that you have to have identical DIMM modules in the channels. It means that the channels must be populated the same. Here is an example:
DIMM 0 = slots 1,2,3
DIMM 1 = slots 4,5,6
Chanel 0 = 1,4
Channel 1 = 2,5
Channel 2 = 3,6
You can have DIMMs of different rank, speed, and capacity mixed across the channels, but you cannot have different configurations. For instance, in this configuration if you populated slots 1,2 with DIMMs then the only valid configuration for DIMM 1 would be populating a single DIMM in slot 4(If the system did not require DIMMs to be installed in pairs) or 2 DIMMs in slots 4,5. You could not populate a DIMM in slot 6 since the first slot(3) in the channel(2) is not populated.
The channel population rule basically means that you cannot populate the second slot in a channel if the first slot is not populated. In your system slot 1 and 4 are in channel 0. All other channels only have a single slot assigned to each memory controller. As long as you have a DIMM iMemory population rules can be very confusing. If you have any more questions let me know.
Thanks
[/quote]
wow thank you so much! I think I get it now!! few quick questions:
so skipping channel 2 (slot 3) isn't a big deal?
if I want more than 20gb, can I purchase one more 8gb (identical) and use those in slots 1,2,3 and put a 4 in slot 4 for an optimal config? I definately want an optimal configuration!
APITech
4 Posts
0
March 9th, 2014 12:00
Just want to be clear - If I took out all of my 4GB DIMMs, I could use 3 8gb quad rank DIMMs to get 24GB?
Also, I would put them in slots 1,2,3 just like the 4 4GB were originally from dell?
Also, I put the two 8GB DIMMs in slots 1,2 and the 4GB in slot 4 like you said for the optimal setting, but I am getting an error still. Seems to want A1-A3 all the same, even though A1,A2 are and I skipped A3
APITech
4 Posts
0
March 9th, 2014 13:00
Ok great thanks so much!!
TSworen
2 Posts
0
April 3rd, 2014 09:00
Daniel My
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6.2K Posts
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April 3rd, 2014 11:00
One other possibility is a failed DIMM. If one of the DIMMs is failed or disabled for some reason then that would cause a mismatch with it's matching DIMM in the other lane. Also, it could cause a population error if there were DIMMs populated in higher channels than the channel the failed DIMM is in.
Daniel My
10 Elder
•
6.2K Posts
0
April 3rd, 2014 11:00
It sounds like it is working. If it is giving a mismatch error then the system thinks that all of the memory is not the same. Either you are using non-validated memory that the system is not able to fully communicate with or not all of the DIMMs are the same.
Thanks
Daniel My
10 Elder
•
6.2K Posts
0
April 3rd, 2014 12:00
No, but most BIOS have the option to disable stop on error. If you turn that off then the error will still show up, but it will not make you press F1 to continue boot.
TSworen
2 Posts
0
April 3rd, 2014 12:00