I have a puzzler. I am dabbling into Lightcoin mining and after setting up all major CPUs on my rigs to go for LTC, I decided to try one of my GPUs.
LTC on CPUs:
i7-3930K, @ 4.1GHz: ~80Khs (11 threads)
Q6600 @ 2.4GHz: ~19KHz
This is my reference for LTC speeds. GPUs should do better than CPUs, right?
My cards, currently mining for BTC are:
2xHD7970 (1150MHz, 300MHz, 1.140v, CrossFire): ~1300 Mhs together
2xHD6670 (960MHz, 400MHz, two different machines): ~127Mhs each
HD6570 (900MHz, 400MHz): ~117MHs
GTX 560 Ti (980MHz, 2400MHz, 1.062v): ~100MHs
All machines have Catalyst 13.1 with the bundled SDK installed.
2D Driver: 8.01.01.1266
Output from cgminer -n
[2013-04-18 12:31:32] CL Platform 0 vendor: NVIDIA Corporation
[2013-04-18 12:31:32] CL Platform 0 name: NVIDIA CUDA
[2013-04-18 12:31:32] CL Platform 0 version: OpenCL 1.1 CUDA 4.2.1
[2013-04-18 12:31:32] Platform 0 devices: 1
[2013-04-18 12:31:32] 0 GeForce GTX 560 Ti
[2013-04-18 12:31:32] CL Platform 1 vendor: Advanced Micro Devices, Inc.
[2013-04-18 12:31:32] CL Platform 1 name: AMD Accelerated Parallel Processing
[2013-04-18 12:31:32] CL Platform 1 version: OpenCL 1.2 AMD-APP (1084.4)
[2013-04-18 12:31:32] Platform 1 devices: 2
[2013-04-18 12:31:32] 0 Turks
[2013-04-18 12:31:32] 1 Turks
[2013-04-18 12:31:32] Failed to ADL_Adapter_ID_Get. Error -1
[2013-04-18 12:31:32] Failed to ADL_Adapter_ID_Get. Error -1
[2013-04-18 12:31:32] Failed to ADL_Adapter_ID_Get. Error -1
[2013-04-18 12:31:32] Failed to ADL_Adapter_ID_Get. Error -1
[2013-04-18 12:31:32] Failed to ADL_Adapter_ID_Get. Error -1
[2013-04-18 12:31:32] Failed to ADL_Adapter_ID_Get. Error -1
[2013-04-18 12:31:32] ADL found less devices than opencl!
[2013-04-18 12:31:32] There is possibly more than one display attached to a GPU
[2013-04-18 12:31:32] Use the gpu map feature to reliably map OpenCL to ADL
[2013-04-18 12:31:32] WARNING: Number of OpenCL and ADL devices did not match!
[2013-04-18 12:31:32] Hardware monitoring may NOT match up with devices!
[2013-04-18 12:31:32] 2 GPU devices max detected
[2013-04-18 12:31:32] USB all: found 12 devices - listing known devices
[2013-04-18 12:31:32] No known USB devices
On PL 1: #0 is HD 6670, #1 is HD 6570
The screen is on nVidia; AMD cards are headless, used solely for mining.
Now that you have the reference speeds, here is what I experience with CGMiner, and Scrypt. I am trying things out on the HD6570 card, so as to see how things turn out and to not impact the ongoing BTC mining too much. I also see
here that HD6570 can be pushed to give ~55Khs
When I run cgminer with almost all default setting, targeting this card, I get ~16Khs:
-T -l 1 --scrypt -g 2 -w 256 --lookup-gap 2 -I d --gpu-platform 1 -d 1
Adding --auto-gpu --thread-concurrency 5760 --gpu-memclock900 I get a whopping 18Khs, which is nowhere near the expected 55
The same story is on the other cards - they perform way below what I would expect to see, based on the tables in the link above.
Am I missing something? To me it looks like it is more profitable to use the cards for BTC mining and leave LTC to my CPUs...