Yeah, I tried -i 2 as well yesterday on a 8gb card. There must be a bug with handling the parallel instances somewhere. But it's rather pointless anyways as for 8gb using the other version is faster. So, I'll probably just remove the code handling parallel solutions and hardcode it to 1 for Zero.

It should work on any card that has at least 4gb of ram. If it doesn't try to reboot the machine and make sure the miner and nothing else runs.

Yes, you can select the cards with '-d N' were N is the number. Use --list-devices to see which device has which number. Then, just run two instances of the miner, one for the 8GB cards and one for the 4GB cards.

Linux version of the 4GB miner will be published soon.

I am pleased to announce the new version of Optiminer/Zero for the ZERO coin that 8GB AMD+NVIDIA cards.

Support for 4GB cards is limited to AMD for now (it runs quite a bit slower with fewer memory!).

Note there are different binaries for 4GB and 8GB cards! The version for the 8GB cards runs faster but needs more RAM.

Download: https://github.com/Optiminer/OptiminerZero

For more information about ZERO see https://bitcointalk.org/index.php?topic=1796036.0

Note this coin is different from Zcash/Zclassic/Zcoin!

For a Zcash/Zclassic miner see https://bitcointalk.org/index.php?topic=1686057.0

While the web frontend for hold.optiminer.pl is "up and down like a yoyo" mining seems to always work, even when the frontend ist down. So, just mine to the pool and observe hodlcoins as they come in to your wallet.

Pool is up again. It should now get restarted daily automatically.

Mining at hodl.optiminer.pl has always worked, just the web server that shows the stats freezes from time to time...

Which modes does work on the problematic cards?

Not from me for now. When the coin gains value someone will port a zcash gpu miner for sure.

They use different mechanisms to transfer data between CPU and GPU.

1.6.2 used PCI mode 0 as default.
1.7 uses 2 as default (which is very similar to 0).
Mode 1/3 are closer to what 1.5 did.

What driver are you using? Note that you need to use Catalyst 15.12 to get the best result.
Also do not forget to deduct the 2.5% mining from from Claymore, so from 228 sol/s you actually get only 222 for you.

Optiminer v1.7.0 released!

[1.7.0] New --pci-modes (0-3). Try if you see GPU freezes.
[1.7.0] Reduced CPU utilization.
[1.7.0] Small performance improvement ~1%.

Enjoy! 

First ever available GPU miner for ZERO:
https://github.com/Optiminer/OptiminerZero#v100

Windows+Linux. AMD only. 8GB cards only.

Make sure you have the blake2b personalization correct:
https://github.com/zerocurrency/zero/blob/master/src/crypto/equihash.cpp#L36

That's what I struggled with.

I will release a closed-source GPU miner with 2.5% dev fee in the next days. It requires AMD cards with at least 8GB memory.

Testing it right now, it gives 8-9 Sol/s on a RX480.

Code is done, doing final testing for 1.7. Then, I just need to build it for all platforms. 1-2 days.

Further speed improvements are very difficult, indeed. I have been experimenting with a different algorithm, but that is (currently) still slower than the current one. Though there is still more room for optimization there.

I plan to release an update on the current algorithm that should bring a small improvement, probably by the end of the week.

Optiminer should be faster. Do not forget that you have to subtract 2.5% for the dev fee on Claymore while optiminer shows hash rates with dev fee subtracted already!

Some of the optimizations do not work with the newer windows drivers. And the RX480 do not work with the old windows driver. So, fully speed for the RX480 only on Linux where all optimizations work with the newer amdgpu-pro drivers that support RX480.

I strongly recommend to use Linux for the RX480.