There is nothing in the manual that would prevent you from populating less than all four for a total of 96GB. The table is merely a "sample" of supported configurations - not all possible configurations.
So, exactly how is mixing supported? The documentation is not clear on this - saying that slots 1-4 can mix sizes, but that channels must be identical (or is that the same as saying the configuration for each processor must be identical - which it also says)?
According to the R515 hardware manual they can be mixed. But I don't want to shell out for memory just to find out that it doesn't work. I want all memory modules used and dont need redundancy. ie. no sparing or mirroring or anything like that.
So I guess my hope is that I can populate it like this: Can anyone in dell test this configuration or advise?
A1 - 16GB (Channel 0)
A2 - 16GB (Channel 0)
A3 - 8GB (Channel 1)
A4 - 8GB (Channel 2)
B1 - 16GB (Channel 0)
B2 - 16GB (Channel 0)
B3 - 8GB (Channel 1)
B4 - 8GB (Channel 2)
"The system contains eight memory sockets split into two sets of four sockets, one set per processor. Each four-socket set is organized into three channels. Two DIMMs for channel 0 and a single DIMM for channel 1 and 2. The first socket of each channel is marked with white release levers."
"Memory modules of different sizes can be mixed in A1-A4 or B1-B4 (for example, 2 GB and 4 GB), but all populated channels must have identical configurations."
Because, slots 1 and 4 are part of the same channel, so by configuring Channel 0 with the same amount of memory as Channels 1 and 2, in theory, it would be able to implement interleaving with more total RAM.
However, maybe Geoff should weigh in on this to explain what the manual doesn't - how mixing should/can be implemented. From what I have seen, mixing sizes will always give you a "non-optimal" message during POST.
The system contains eight memory sockets split into two sets of four sockets, one set per processor. Each four-socket set is organized into three channels. Two DIMMs for channel 0 and a single DIMM for channel 1 and 2. The first socket of each channel is marked with white release levers.
The motherboard diagram seems to think there are three (white release levers):
But the description of the memory slots (4,8) seem to agree with you, obviously conflicting with the diagram and what is written above:
So, I don't have one of these ... what is the real scoop? Can we get the manual fixed?
I agree that the manual on this is incorrect and appears they copied part of the memory config from another server. I will pass this along for correction.
From the User's Guide : http://ftp.dell.com/Manuals/all-products/esuprt_ser_stor_net/esuprt_poweredge/poweredge-r515_Owner%27s%20Manual_en-us.pdf There are only 2 channels per processor, page 106.
The 16GB RDIMM's will work in the white lever slots (1,2) or in all 4, but not mixed with other RDIMM's. Since 32GB RDIMM support has been added as well, they must also be in the slots with white levers, and only allowed capacity is 2 per processor, for a total of 128GB. You may be able to add the 2 additional 8GB RDIMM's to slots 3,4, but you may get the memory is not optimal error at startup; it may continue to POST or it may halt. If it halts, then the 8GB RDIMM's would have to be removed.
After further research, with the release of the 32GB RDIMM's support was increased from 128GB to 256GB on this server as well, which requires the latest bios update. I also confirmed that the server does indeed only have 2 channels per processor.
DELL-Geoff P
990 Posts
0
February 28th, 2013 07:00
Good morning, Jorg.
On the PER515, the supported memory goes from 64gb to 128gb, with nothing in between. The manual is correct in using the 16gb RDIMM's.
Regards,
theflash1932
9 Legend
•
16.3K Posts
0
February 28th, 2013 08:00
These should all be valid (including the 96GB):
16-x-x-x | 16-x-x-x = 32GB
16-16-x-x | 16-16-x-x = 64GB
16-16-16-x | 16-16-16-x = 96GB
16-16-16-16 | 16-16-16-16 = 128GB
There is nothing in the manual that would prevent you from populating less than all four for a total of 96GB. The table is merely a "sample" of supported configurations - not all possible configurations.
So, exactly how is mixing supported? The documentation is not clear on this - saying that slots 1-4 can mix sizes, but that channels must be identical (or is that the same as saying the configuration for each processor must be identical - which it also says)?
Jorg Lenhof
3 Posts
0
February 28th, 2013 08:00
According to the R515 hardware manual they can be mixed. But I don't want to shell out for memory just to find out that it doesn't work. I want all memory modules used and dont need redundancy. ie. no sparing or mirroring or anything like that.
So I guess my hope is that I can populate it like this: Can anyone in dell test this configuration or advise?
A1 - 16GB (Channel 0)
A2 - 16GB (Channel 0)
A3 - 8GB (Channel 1)
A4 - 8GB (Channel 2)
B1 - 16GB (Channel 0)
B2 - 16GB (Channel 0)
B3 - 8GB (Channel 1)
B4 - 8GB (Channel 2)
"The system contains eight memory sockets split into two sets of four sockets, one set per processor. Each four-socket set is organized into three channels. Two DIMMs for channel 0 and a single DIMM for channel 1 and 2. The first socket of each channel is marked with white release levers."
"Memory modules of different sizes can be mixed in A1-A4 or B1-B4 (for example, 2 GB and 4 GB), but all populated channels must have identical configurations."
Jorg Lenhof
3 Posts
0
February 28th, 2013 09:00
Thanks theflash1932, I agree with having the same amount in each channel
ie. channel 0 = 2x8GB, channel 1 = 16GB and channel 2 = 16GB
I currently have 8x8GB installed so would like to reuse 4 of the 8GB modules.
theflash1932
9 Legend
•
16.3K Posts
0
February 28th, 2013 09:00
If it were me, I would install them like this:
8-16-16-8 | 8-16-16-8 = 96GB
Because, slots 1 and 4 are part of the same channel, so by configuring Channel 0 with the same amount of memory as Channels 1 and 2, in theory, it would be able to implement interleaving with more total RAM.
However, maybe Geoff should weigh in on this to explain what the manual doesn't - how mixing should/can be implemented. From what I have seen, mixing sizes will always give you a "non-optimal" message during POST.
theflash1932
9 Legend
•
16.3K Posts
0
February 28th, 2013 12:00
On page 104:
The system contains eight memory sockets split into two sets of four sockets,
one set per processor. Each four-socket set is organized into three channels.
Two DIMMs for channel 0 and a single DIMM for channel 1 and 2. The first
socket of each channel is marked with white release levers.
The motherboard diagram seems to think there are three (white release levers):
But the description of the memory slots (4,8) seem to agree with you, obviously conflicting with the diagram and what is written above:
So, I don't have one of these ... what is the real scoop? Can we get the manual fixed?
DELL-Geoff P
990 Posts
1
February 28th, 2013 12:00
I agree that the manual on this is incorrect and appears they copied part of the memory config from another server. I will pass this along for correction.
Regards,
DELL-Geoff P
990 Posts
0
February 28th, 2013 12:00
Jorg\Flash,
From the User's Guide : http://ftp.dell.com/Manuals/all-products/esuprt_ser_stor_net/esuprt_poweredge/poweredge-r515_Owner%27s%20Manual_en-us.pdf There are only 2 channels per processor, page 106.
The 16GB RDIMM's will work in the white lever slots (1,2) or in all 4, but not mixed with other RDIMM's. Since 32GB RDIMM support has been added as well, they must also be in the slots with white levers, and only allowed capacity is 2 per processor, for a total of 128GB. You may be able to add the 2 additional 8GB RDIMM's to slots 3,4, but you may get the memory is not optimal error at startup; it may continue to POST or it may halt. If it halts, then the 8GB RDIMM's would have to be removed.
Regards,
DELL-Geoff P
990 Posts
0
February 28th, 2013 13:00
After further research, with the release of the 32GB RDIMM's support was increased from 128GB to 256GB on this server as well, which requires the latest bios update. I also confirmed that the server does indeed only have 2 channels per processor.
Regards,