Rise of the Mining Dead
How to continue mining Ethereum with your 4G AMD GPUs for some more epochs
Introduction
On December 16th (beginning of epoch 382) all 4G GPUs will drop off the Ethereum network because the DAG size approaches 4 GByte and will be too large for this cards.
Well, as a rule of thumb the above mentioned may be right, but the reality is more complex. In fact some of this cards already struggle today due to manifold reasons, e.g. using old mining software and driver versions, using Windows OS or just because you run a different Vendor of cards. In fact the barrier of epoch 381 mostly applies to 4G cards of AMD brand running on a modern driver and mining software on a Linux based mining OS. But even then there are cases where some combination of cards and drivers are able to manage mining in DAG epoch 382.
But then on December 21th, when epoch 383 will be reached, this is the end for all 4G cards and also ASICs on the Ethereum network?
Again, the answer maybe is surprising, but No! This article will explain how to continue mining and how to max out the last weeks of Ethereum mining with your 4G AMD GPUs.
A Miner that goes on
Recently there was a new release of lolMiner — an AMD GPU focused mining software — that offers a special mining mode called zombie mode for continue mining on 4G GPUs even when they run out of memory to hold the DAG file.
I was asked why zombie mode. Well I found that term fitting. This are cards that are supposed to be dead, yet they continue mining but gradually slower. Like an undead (GPU).
The mode will work on both relevant operation systems — Linux and Windows — but with a better efficiency and a longer lasting effect on Linux. In the table are performance examples for a 4G 580 GPU that mines 30mh/s with the complete DAG fitting into the card.
How to set it up
There is only one thing that lolMiner need to know to run the zombie mode successfully. This is the last epoch the miner can run without issues in the normal mining mode, so lolMiner does not allocate more memory then it can without messing things up.
The only parameter to influence this is “ keepfree” which gives the number of megabytes the miner shall not use on the card to reserve it for the system.
By default this value is set to 56 MBytes in Windows and 5 MBytes in Linux, which should work fine. But how to try out?
The easiest way is to benchmark lolMiner at an epoch that is larger then 383 — in this case all the 4G cards will enter the Zombie mode and use as much memory as the default “keepfree” allows. To do so run e.g. benchmark for epoch 385:
In Linux:
./lolMiner --benchmark ETHASH --benchepoch 385 --keepfree 5In Windows:
lolMiner.exe --benchmark ETHASH --benchepoch 385 --keepfree 56
For this purpose lolMiner 1.11 ships with a bench_epoch_395.sh and bench_epoch_395.bat example scripts.
Now there are two cases:
A) Your miner boots up
with all 4G cards running at reasonable hashrate (see above)
That is perfect! In this case the parameter is set right or maybe too high. But its a working configuration.
You can try to rerun the miner with a value of “keepfree” that is 8 Mbytes lower (e.g. in Linux: change from 5 to 0, Windows: change from 56 to 48)
Repeat until scenario B) appears
B) The miner gets killed / freezes the rig or get horribly slow
In this case you pushed it too far. Restart the rig, increase “keepfree” by 8 (MBytes) and try it again, until it starts up.
When done with figuring out the right “keepfree” parameter, then just add it to the list of lolMiner parameters when start mining. Thats it!
Have fun using this new opportunity to continue mining with your 4G AMD cards! Feedback welcome!
