Hello forum members,
This is my first post here, but bear with me. I have come here after searching the internet for a while (like most of us do)
We are in the process of figuring out which memory option would be the best for our needs. What are our requirements? Very simple
1) Bandwidth: BW TB/s, say greater than 20TB/s
2) Capacity: C TB, say 20TB
Aim: Which memory technology can meet our demands at the lowest power? And it is alright if the power numbers are not extremely accurate
Memory Options:
1) DDR5
2) HBM3 or 3e
3) LPDDR5
There are two ways to go about calculating the power:
1) Using pJ/bit: How much energy it takes to fetch 1 bit from the memory and then multiply it by the total amount of data you want to fetch
2) Avg Power: Find average power numbers, say for a single DIMM of DDR5 and multiply it by the total number of DIMMs required to meet the capacity and BW requirement i.e max(BW/(Single DIMM BW), C/(Single DIMM Capacity))
The main challenge: finding reliable power numbers either through the internet or even simulators.
For example: As per the paper here, following are the energy per bit numbers
whereas, if we check the youtube video here, they provide avg power for different operating clock frequency, using which I get around 19Pj/bit number.
I understand that pj/bit numbers vary highly with the operating frequency and even the capacity of the memory macro.
My question to all the experts and enthusiasts is: How do I go about getting a good enough estimate for the problem above and what numbers to rely upon?
This is my first post here, but bear with me. I have come here after searching the internet for a while (like most of us do)
We are in the process of figuring out which memory option would be the best for our needs. What are our requirements? Very simple
1) Bandwidth: BW TB/s, say greater than 20TB/s
2) Capacity: C TB, say 20TB
Aim: Which memory technology can meet our demands at the lowest power? And it is alright if the power numbers are not extremely accurate
Memory Options:
1) DDR5
2) HBM3 or 3e
3) LPDDR5
There are two ways to go about calculating the power:
1) Using pJ/bit: How much energy it takes to fetch 1 bit from the memory and then multiply it by the total amount of data you want to fetch
2) Avg Power: Find average power numbers, say for a single DIMM of DDR5 and multiply it by the total number of DIMMs required to meet the capacity and BW requirement i.e max(BW/(Single DIMM BW), C/(Single DIMM Capacity))
The main challenge: finding reliable power numbers either through the internet or even simulators.
For example: As per the paper here, following are the energy per bit numbers
whereas, if we check the youtube video here, they provide avg power for different operating clock frequency, using which I get around 19Pj/bit number.
I understand that pj/bit numbers vary highly with the operating frequency and even the capacity of the memory macro.
My question to all the experts and enthusiasts is: How do I go about getting a good enough estimate for the problem above and what numbers to rely upon?