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todxx / teamredminer

AMD GPU Optimized Cryptocurrency Miner
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Enable C Mode on RX 6800+ ? #581

Open AlbyGNinja opened 2 years ago

AlbyGNinja commented 2 years ago

I ran 6800xt for a while on A Mode and I just look into amd-info and seen TRM allocate only 5.ish gb of space in vram, which is so low compared to 16gb of total space. So, because B and C are made to allocate more space for those gpus with more Vram I used at first the B mode, and because the autotune, TRM used B900+ which is massive, pumping up the space allocated to 8gb as expected. Then I tried to use the C mode, made for Radeon VII because of the 16gb but TRM starts tuning with B mode instead of C. Why this? Why C mode is not implemented on high mem space like 6800-6900?

On Radeon VII moving from B to C mode increase the hashrate from 80-82 up to 100+! This is massive improvement! 6800-6900 can do much better than this little 62mh compared to other same level gpus! image

gongdao123 commented 2 years ago

The reason why rx6800 is using A mode is explained in ETHASH_TUNING_GUIDE.txt

Navi21 (6800/6800XT/6900XT)

TRM v0.8.1 added basic support for Big Navi cards (Navi21). This section will be expanded as we do more work for this gpu generation. For now, the suggested tuning process is quite simple: 1) Big Navis should run in A-mode (it's chosen by default). While the B-mode is available, the value of the 128MB cache is degraded with a larger memory footprint.`