Winter is Coming Miner

Server Memory Configuration

Aquila Systems, November 2021

The Winter is Coming (WIC) Miner is an Ethereum cryto-currency miner that uniquely is designed to run on Intel/AMD based server type computer systems.    

 We assume you have opened up at least a few of the servers in your organization, removed the air flow hood (if present) and seen a large number of slots for memory modules.    You will likely only see a quarter, third, or half of these that are populated with memory modules.    This is fine but the arrangement of this population can make a big difference to the performance of the WIC Miner.

You will get the best performance when all available memory channels are populated with at least one stick of RAM!     If only half the memory channels are populated you will only get about half the mining hash rate.

The only real requirement by the Servers hardware/firmware is that each physical CPU has identical capacity memory modules on each channel of the physical CPU.

You server / system board manual will likely show a pictorial view of which slots go with which CPU and memory channel.     If it does not, in most cases this info can be derived from text on the system board.     However even without documentation it should be obvious which slots go with which CPU as physics requires that they be close to their CPU.     Then on most system boards the first memory slot you should populate per channel should be blue in color.    So assuming that you see these blue colored slots simply make sure that all these are populated and you should be fine.    In some cases this means just moving modules from black slots to blue slots.     Not just the WIC Miner but all software will perform better by properly arranging the memory as described here.

Here are two examples:

Millions of dual processor Intel Xeon E5-26XXv3/4 Haswell based computer systems were sold from 2015-2020.    These processors have 4 memory channels per CPU that can each hold 2 DDR4 registered memory modules.    Between the two CPU’s you have 8 channels and 16 memory slots.    They are always symmetric around each CPU so assuming you have 8 DDR4 memory modules available you will want to populate the furthest slot on each side of both CPU’s then moving inward skip a slot and then populate the next slot, again the slots to populate should be blue in color.    If you only have 4 DDR4 modules that are identical I would suggest acquiring 4 new DDR4 modules they do not have to be the same manufacturer or capacity (you should be able to use these for future systems for years to come, so wise investment).    Then populate one CPU with the 4 existing DDR4 modules and the other CPU with the 4 new DDR4 modules.     We do this as the two CPU’s can have different memory but all the channels of each CPU should have the same memory type and capacity.

A no cost memory module acquisition idea is to take a server not being used and remove its memory to fully populate all channels of the server that will run the WIC Miner.    Just keep track so that in the Spring you can put it back.

AMD Epyc based servers were also very popular over past 4 years as team red found its way back into CPU’s in 2017 with Ryzen and Epyc.     The Epyc Gen 1 CPU’s are different from anything of past by either Intel or AMD where each package had a single CPU chip.   In Epyc each package contains 4 CPU chips that to software look like 4 physical CPU nodes.   Each internal CPU chip drives two memory controllers and each package therefore has 8 memory channels.    So if you have a dual CPU (package) Epyc system you really have 8 CPU’s and 16 memory channels.     Some Epyc systems have just one slot per channel and others have 2.    If you only see 8 memory slots around each CPU then you should populate all 8 slots on each CPU.    If you see 16 slots then every other slot starting from the outer most ones on each side should be populated.   These slots should be blue in color.    

At a minimum half the channels (alternate or every other) on each CPU must be populated for the WIC Miner to run but in this case you will not achieve fast hash rates.     

As noted earlier you will be rewarded by populating all channels as with modern Xeon or EPYC it linearly scales and each populated channel results in 0.8Mhash/sec so with a dual CPU Epyc system you can obtain about 12Mhash/sec with all 16 memory channels populated.

Desktop systems have just 2 memory controllers which for the WIC Miner they must both be populated to achieve >1 Mhash/sec.    It is this lack of multiple memory channels on desktop systems that make these systems a poor choice for this application, despite fast processors.