Archive for the ‘General Info’ Category


It seems that owners of video cards with 2GB of video memory has started having issues mining Ethereum (ETH). People are reporting that their cards are not being able to properly allocate the DAG file needed for mining with Ethminer even though it is still well below 2GB in size (a little over 1.3 GB at the moment). The error people with 2GB VRAM GPUs trying to mine Ethereum are getting is the following:

Creating one big buffer for the DAG
Allocating/mapping single buffer failed with: clCreateBuffer(-61). GPU can’t allocate the DAG in a single chunk. Bailing.

There are numerous suggestions on how some people were able to resolve the problem and make their 2GB VRAM video cards able to mine again Ethereum without more problems, but it seems that now all of them work for everyone and in all cases. We have tried different suggestions and have experimented, until we have found out a working solution that works fine on an AMD Radeon R9 285 GPU with 2GB of video memory, so you might want to try and see if it will work for you as well. Try executing the following commands in Windows before running ethminer and see if it will help:


Some people are reporting that they only need to do “setx GPU_MAX_ALLOC_PERCENT 100” and things work fine after that with their 2GB GPUs, but we were not able to make things work only with that variable. So do try and report what works and what does not for you, setting all of the four environment variable listed above did the trick for us. Restarting the computer after applying the environment variable listed above may be required for some users to make them work properly. Using 14.x drivers seems to provide the best success rate for most people, so if you are using newer 15.x drivers and still having issues, you might try going back to 14.x.

Linux users might try this as well, however you need to replace the setx with export and add = before the value you want to set, so the above list of commands needed for Linux users mining Ethereum should look like this:

export GPU_FORCE_64BIT_PTR=0
export GPU_MAX_HEAP_SIZE=100

Do note that we have not tested if this fixes the issue for Linux users, we can confirm that it worked for us under Windows, so if you test on Linux mining rigs with 2GB video memory GPUs please write in the comments if it helped you or not.


Some very good news for the very few owners of the first batch of iBeLink DM384M X11 ASIC miners, but also for GPU miners as well – X11 mining profitability on NiceHash has skyrocketed in the last hours and is still keeping high. Selling X11 hashrate on NiceHash has been the most profitable long term choice since the beginning of this month and the preferred choice for the 50 lucky owners of the first batch of iBeLink X11 ASICs. Today however we are seeing the X11 profitability more than doubling compared to what it was just a few days ago.

Now, some people are considering that X11 is already a lost cause for GPU mining, but it is too early for that as there are still very few X11 ASIC miners available and with high profitability increase like the one at the moment you should take advantage even with GPUs, let alone to miss the opportunity if you have an ASIC miner in your hands. The next batch of iBeLink X11 ASICs is expected around mid-May and even then the number of available units will most likely be small as compared to what we have seen with LTC ASIC miners fooling the market when they first appeared. So if you are not mining Ethereum or Decred with your GPUs you might want to check the profitability for X11 for your GPU mining rigs, and even if you are mining ETH or DCR you might still check if this X11 peak will not be more profitable on the short run.

If you want to check your current X11 GPU/ASIC mining profitability on What to Mine…


We were not among the ones to preorder the last ASIC mining hardware that KnCMiner has sold to users, the Titan, but recently we have obtained some KNC Titan Scrypt ASICs to play with. The first thing you will notice is that even the latest official firmware of the devices version 2.0 is still pretty basic and the hardware is buggy, especially the earlier batch 1 devices. So we started looking for an improved version of the original firmware that would allow us to get the best out of the KNC Titan Scrypt ASIC and we have ended up discovering GenTarkin’s Custom KNC Titan firmware.


This modified firmware provides users with an improved and more functional interface and more importantly a safer to use and capable of providing you with the optimal performance and power usage that your Titan cubes can provide you with. This of course comes at a price, you need to purchase a full license for the modified firmware that is currently sold at $75 USD for the controller and if you have an additional devices you can purchase extra licenses for $35 USD each for each controller (key for activation only), not for each cube. There are also additional discounts available for volume licensing for purchases of 10 or more licenses for large miners with more devices available.


We have just started using the latest version 1.0.2 of GenTarkin’s Custom KNC Titan Scrypt ASIC firmware on the hardware we have obtained and as you can see on the screenshot both cubes we have attached to the controller have some issues with some of the chip dies and DCDC power units. You can see the difference in how the advanced settings page looks like for both the stock and the custom firmware. The power usage for example on the custom firmware reports more accurate power usage numbers and when you take into account the power efficiency of the PSU you can get pretty accurate power consumption numbers for the actual power used at the wall. There are number of additional protection mechanisms built in as well as optimizations to help run your mining hardware stable and with less issues on the long run. The Energy Saver is also something new and very interesting feature that supposedly can help you find the optimal settings for each die and thus help you get lower power usage while retaining optimum performance.

We have just started using GenTarkin’s Custom KNC Titan firmware and so far we like the improvements and extra features we see from the latest stock firmware from KNC, in a few days we are going to be sharing more from our experience as well as doing a more detailed review. Meanwhile if you have some KNC Titan Scrypt ASIC miners and you are using the stock firmware you might be interested in checking out this custom firmware, especially if you are having some issues with your devices or have more than one miners.

Visit the official website for GenTarkin’s Custom KNC Titan Firmware for more info…