mixing RAM size and speeds faster than max CPU specs speed.
by BW-userx from LinuxQuestions.org on (#4XH6Z)
I've only encountered the subject of dual channel RAM same speeds advice/info/
Code: To take advantage of a dual-channel platform when purchasing memory
make sure to buy memory in identical pairs. For example, if you wanted
to upgrade to an additional 2 GB of memory. Buy two 1 GB memory modules
that are exactly identical. While the speed of each memory chip does not
need to be the same as the others, it is best to install memory with
matching speeds. If the speeds differ, the motherboard runs the memory
chips at the speed of the slowest chip.source https://www.computerhope.com/jargon/...nel-memory.htm
I've also read that if the MB or CPU max ram speed is say 1233MHz then faster speed is not obtainable. easy enough to understand. But,
I got 2400T 8GB and a 2666MHz 16GB.
Code:
$ sudo dmidecode --type 17
# dmidecode 3.2
Getting SMBIOS data from sysfs.
SMBIOS 2.7 present.
Handle 0x0018, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x0005
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 16384 MB
Form Factor: SODIMM
Set: None
Locator: Bottom-Slot 1(left)
Bank Locator: ChannelA
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 2133 MT/s
Manufacturer: Unknown - [0x4909]
Serial Number: 00000000
Asset Tag:
Part Number: D1D4S816GB1G81G82666
Rank: 2
Configured Memory Speed: 2133 MT/s
Minimum Voltage: Unknown
Maximum Voltage: Unknown
Configured Voltage: 1.2 V
Handle 0x0006, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x0005
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 8192 MB
Form Factor: SODIMM
Set: None
Locator: Bottom-Slot 2(right)
Bank Locator: ChannelB
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 2133 MT/s
Manufacturer: Hynix/Hyundai
Serial Number: 42285CA6
Asset Tag:
Part Number: HMA81GS6MFR8N-UH
Rank: 1
Configured Memory Speed: 2133 MT/s
Minimum Voltage: Unknown
Maximum Voltage: Unknown
Configured Voltage: 1.2 Vin Linux it states 2133 MT/s for both. in Windows using CPU Z it shows the 16 at 1333 X 2 = 2666 and various speeds ( I'd have to go back into windows and run it again to copy everything over on here).
the question is as it says mixed ram runs at the lowest speed of the two mixed RAM sticks. but it looks to me that if the two sticks are faster speed then the cpu rated max speed it does not matter.
as CPU z shows dual channel is being used in windows, I do not know about Linux. I have not found a method to show me if that is the case in Linux. I assume it should be.
therefore, if the two mixed speeds and sizes are being limited to just 2133 it does not matter if one RAM stick is 2666MHz and the other is 2400T MHz the both looks like to me are being throttled down to 2133MHz and put into duel channel so what I have been reading about is not the real skinny on how RAM works together.
they are all just logical suggestions???
this is a laptop
hp 840 g3
CPU Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
RAM 23451 MB : 443 : 21613
Graphics Card [HD Graphics 520] (rev 07)
Code: To take advantage of a dual-channel platform when purchasing memory
make sure to buy memory in identical pairs. For example, if you wanted
to upgrade to an additional 2 GB of memory. Buy two 1 GB memory modules
that are exactly identical. While the speed of each memory chip does not
need to be the same as the others, it is best to install memory with
matching speeds. If the speeds differ, the motherboard runs the memory
chips at the speed of the slowest chip.source https://www.computerhope.com/jargon/...nel-memory.htm
I've also read that if the MB or CPU max ram speed is say 1233MHz then faster speed is not obtainable. easy enough to understand. But,
I got 2400T 8GB and a 2666MHz 16GB.
Code:
$ sudo dmidecode --type 17
# dmidecode 3.2
Getting SMBIOS data from sysfs.
SMBIOS 2.7 present.
Handle 0x0018, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x0005
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 16384 MB
Form Factor: SODIMM
Set: None
Locator: Bottom-Slot 1(left)
Bank Locator: ChannelA
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 2133 MT/s
Manufacturer: Unknown - [0x4909]
Serial Number: 00000000
Asset Tag:
Part Number: D1D4S816GB1G81G82666
Rank: 2
Configured Memory Speed: 2133 MT/s
Minimum Voltage: Unknown
Maximum Voltage: Unknown
Configured Voltage: 1.2 V
Handle 0x0006, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x0005
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 8192 MB
Form Factor: SODIMM
Set: None
Locator: Bottom-Slot 2(right)
Bank Locator: ChannelB
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 2133 MT/s
Manufacturer: Hynix/Hyundai
Serial Number: 42285CA6
Asset Tag:
Part Number: HMA81GS6MFR8N-UH
Rank: 1
Configured Memory Speed: 2133 MT/s
Minimum Voltage: Unknown
Maximum Voltage: Unknown
Configured Voltage: 1.2 Vin Linux it states 2133 MT/s for both. in Windows using CPU Z it shows the 16 at 1333 X 2 = 2666 and various speeds ( I'd have to go back into windows and run it again to copy everything over on here).
the question is as it says mixed ram runs at the lowest speed of the two mixed RAM sticks. but it looks to me that if the two sticks are faster speed then the cpu rated max speed it does not matter.
as CPU z shows dual channel is being used in windows, I do not know about Linux. I have not found a method to show me if that is the case in Linux. I assume it should be.
therefore, if the two mixed speeds and sizes are being limited to just 2133 it does not matter if one RAM stick is 2666MHz and the other is 2400T MHz the both looks like to me are being throttled down to 2133MHz and put into duel channel so what I have been reading about is not the real skinny on how RAM works together.
they are all just logical suggestions???
this is a laptop
hp 840 g3
CPU Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
RAM 23451 MB : 443 : 21613
Graphics Card [HD Graphics 520] (rev 07)