All About BTC, LTC, ETH mining as well as other alternative crypto currencies
When looking for the best settings for GPUs that will be used for crypto currency mining it is often considered a good practice to optimize them for better efficiency and not for maximum performance. Going for the maximum performance often results is overclocking and thus higher power usage for the extra few hashes, not to mention the additional heat and as a result the overall efficiency may not be as good. If you are looking for the optimal efficiency you will most likely try to reduce the power usage of the GPU to decrease the power usage and heat output and not sacrifice any or at the cost of just a little performance drop. This is exactly what we are going to be doing now with the recently announced Nvidia GeForce GTX 1080 Ti Founders Edition video card, trying to find the sweet spot in terms of efficient (best hashrate per Watt of power used)…
For the purpose of our tests we are using the latest NiceHash Excavator v1.1.4a miner running on the Equihash algorithm used by Zcash (ZEC). Do note that other algorithms may need different settings for reaching better efficiency than the one tested here. Currently the Equihash algorithm is among the most profitable to mine on Nvidia CUDA GPUs, so we are focusing on it. Since all recent GPUs from Nvidia have both a base operating frequency and a boost operating frequency and the video card is managing the optimal one based on factors such as TDP and temperature it is easy to look for better efficiency just by lowering the TDP limit. This will essentially result in lowering the maximum boost frequency of the GPU and is an easy and very good thing to start from, if you wan to dig deeper you may also try to lower the operating voltage of the GPU in order to further improve the efficiency by lowering the power usage.
In the table above we start with the GTX 1080 Ti running at the maximum TDP level that is allowed with the +20% increase of the Power Limit meaning 250W default TDP + 50W increase or a total of 300W allowed. At this maximum allowed level you cannot expect to be anywhere near the optimum efficiency, not to mention that the GPU may not be able to reach that power usage anyway without further overclocking. We are however going to stay at the default settings and not overclock, playing only with the boost frequency of the GPU by lowering the TDP. The final result showed that the optimum efficiency in terms of hashrate per Watt is with around 60% TDP or about 150W for the GTX 1080 Ti… that is for the Equihash algorithm used by Zcash (ZEC). With that setting the operating frequency of the GPU stays at just a bit shy of 1500 MHz, or to be more precise at the 1480 MHz base operating frequency. What essentially this means is that while the extra Boost frequency may rise the performance you get, the more it scales up, the less efficient the GPU becomes in terms of performance per Watt of power used. No wonder Nvidia has chosen this particular operating frequency as the base one for the GTX 1080 Ti, and the GPU manages to keep it up with a TDP of just 150W for mining the Equihash algorithm. Do note however that other mining algorithms, especially more GPU dependent, may need more power for their efficiency sweet spot on the GTX 1080 Ti.
Time for another group of tests of the newly released GeForce GTX 1080 Ti Founders Edition video card by Nvidia. This time we have used the latest released of the ccMiner 2.0 RC2 fork by Tpruvot in order to test how all of the supported algorithms perform on the new GPU. Do note that not all of the supported crypto algorithms by this miner may be performing the fastest, so you should use the results as a reference if comparing results from 2.0 RC2 release only. We have managed to successfully test the hashrate on most of the supported algorithms by this miner, though we still did have trouble making some of them work, but that is to be expected with a new GPU release…
We have used ccMiner 2.0 RC2 by tpruvot in benchmark mode with all of the default settings for intensity on all algorithms supported by the miner. The GeForce GTX 1080 Ti GPU was running at the default 100% TDP or with other words a Power Limiter at 250W, though on the Founders Edition GPUs you can increase it by up to 20% all the way to 300W (mind the cooling though). The tests were performed on stock operating frequencies of the video card with the fan set at 100% in order to keep the GPU cool and prevent thermal throttling (dropping of the boost frequency) because of high temperature that might be reached with auto fans.
As you can see in the table with performance results above we have posted the hashrate and the power usage for each algorithm tested (if the test has successfully passed). The power usage values are the ones reported by the video card itself only and are based on its TDP limit, not the actual values measured at the wall (these will be higher). The algorithms pushing the 250W TDP limit might be able to benefit from a power limit increase, though you might want to be careful with that in terms of being able to properly cool down the card. On the other hand forcing the TDP limited down might bring significant power reduction with a little sacrifice in terms of hashrate thus giving you better performance per Watt than the stock settings.
With the BMW algorithm we got an error at the default intensity of 21, and we’ve had to decrease it down to 15 in order to make it work, resulting in very low hashrate. With Cryptonight we got an error at the default intensity of 10.75, but down to 10.25 it worked and you can see the result in the table. With the Jackpot algorithm we also got an error at the default intensity of 20, however lowering it did not seem to help at all and the same thing also applies to the Quark algorithm. With the Wildkeccak algorithm we had trouble making it work properly in benchmark mode due to the specifics of the algorithm needing a scratchpad file.
The GeForce GTX 1080 Ti is the latest addition in Nvidia’s lineup of high-end gaming GPUs, but here we are more interested in another aspect for using these video cards – crypto mining. Tomorrow, March 10th, the sales of the new Nvidia GeForce GTX 1080 Ti should start priced at $699 USD, though initially there will be only Founders Edition models only with availability of non-reference designs expected to start showing for sale in April. The GeForce GTX 1080 Ti is based on GDDR5X memory clocked at 11 GHz, so the memory timings might not be the best for memory-based crypto algorithms, but the serious number of CUDA cores is there to compensate in terms of performance. Do note that the TDP of the new cards is set at 250W, though we expect that you should be able to lower the Power Limit a bit and get a better results than at stock settings.
Nvidia GeForce GTX 1080 Ti Specifications:
– Graphics Processing Clusters: 6
– Streaming Multiprocessors: 28
– CUDA Cores (single precision): 3584
– Texture Units: 224
– ROP Units: 88
– Base Clock: 1480 MHz
– Boost Clock: 1582 MHz
– Memory Clock: 5505 MHz
– Memory Data Rate: 11 Gbps
– L2 Cache Size: 2816K
– Total Video Memory: 11264MB GDDR5X
– Memory Interface: 352-bit
– Total Memory Bandwidth: 484 GB/s
– Texture Rate (Bilinear): 331.5 GigaTexels/sec
– Fabrication Process: 16 nm
– Transistor Count: 12 Billion
– Connectors: 3 x DisplayPort, 1 x HDMI
– Form Factor: Dual Slot
– Power Connectors: One 6-pin, One 8-pin
– Recommended Power Supply: 600 Watts
– Thermal Design Power (TDP): 250 Watts
– Thermal Threshold: 91° C
We have managed to do some quick testing of the new GTX 1080 Ti and the results do seem promising. Starting with the currently more profitable algorithms on NiceHash and benchmarking with their NiceHash Miner that uses various fast performing miners (the miner used is noted after the algorithm). Not all of the latest and highest performing miners may be included, so we also ran some additional tests using the Claymore ETH miner that managed to provide a stable hashrate of about 31.8 MHS with stock settings of the card as well as the latest EWBF CUDA miner that managed to squeeze a bit more at about 625 H/s from the GTX 1080 Ti.
You can use these numbers as a reference, including the expected daily profitability if selling the hashrate form a GTX 1080 Ti on NiceHash that their miner also reports. Hopefully we are going to be able to run some more benchmarks in the next couple of days and play around to see what the GPU is capable in terms of overclocking, though with the pretty high boost frequency and a TDP of 250W you should not be expecting a lot more at least from the Founders Edition version that is launching first. Do note that properly powering and cooling six of these GPUs in a mining rig is not going to be as easy as with GTX 1070 Founders Edition for example that consume much less power and are a much more popular choice by miners using Nvidia GPUs.
Do note that with the launch of the GTX 1080 Ti, Nvidia is also going to have a new pricing for the GeForce GTX 1080 Founders Edition and GeForce GTX 1080 partner boards that will get a bit more cheaper. There is no word on reducing the prices of the GTX 1070 as well however. Furthermore two new models with higher clocked video memory should be available soon, the GeForce GTX 1080 with 11 Gbps along with the already available 10 Gbps model as well as GeForce GTX 1060 9 Gbps along the already available 8 Gbps versions. The faster memory variants might be of interest especially for the miners that are into mining crypto currencies based on algorithms that are more memory dependent such as ZEC or ETH for example.