Litecoin Mining – HIS Radeon R9 280X Sweet Spot for 730KHash/sec
Keeping up with the R9 280X cards, this time i will share my configurations for the HIS R9 280X card. Previously, i have mentioned that CGMiner version 3.7.2 with the latest drivers would give you a higher hashrate as the R9 cards would be classified properly as 200 series cards. With the updated driver, R9 280X cards would run much cooler and most could reach above 700KHash/sec.
Another important condition to note when tweaking with the R9 280X is the BIOS. All the R9 280X GPUs that i came across can cross the 700KHash/sec mark. Some cards will get a higher hashrate with updated mining software drivers while others need an updated BIOS. HIS R9 280X will only reach 670KHash/sec on stock BIOS, and the hashrate is around 730KHash/sec with the updated BIOS.
How to optimize HIS R9 280X for Litecoin mining
Since the 280X is a rebranded 7970, it is possible to undervolt the cards using the VBE7 method that i have outlined in the previous tutorial: How to modify video BIOS to undervolt GPU in Linux. There is an additional step before you attempt to undervolt the BIOS though.
In my testing, HIS R9 280X will only pass the 700KHash/sec mark after updating the BIOS. If you are experiencing the same issue as mine, you can try to update with this BIOS and use VBE7 to load this instead:
After flashing the BIOS, HIS runs completely stable at 1100mV, so if you are using my undervolting method, simply replace the 1081mV that i have recommended with 1100mV.
For this test, i am using BAMT version 1.1 with the latest AMD Catalyst drivers installed and CGMiner 3.7.2. You may learn more about setting up BAMT in my tutorial: Litecoin BAMT version 1.1 – Easy USB Linux mining distro.
I get the best result from this CGMiner configuration:
-g 2 -w 256 -I 13 --lookup-gap 2 --thread-concurrency 8192 --gpu-engine 1050 --gpu-memclock 1500
This configuration gets me around 730KHash/sec on each card with a low reject ratio. Most brands of R9 280X can reach hashrate of above 700KHash/sec. I will try to spend some time and post the configurations for each and every R9 280X i can get my hands on.