Questions:

1. Why is NiceHash QuickMiner started with administrator privileges? 2. What happens when DAG is being generated? 3. Where can I see number of accepted and rejects shares? 4. Why do some jobs have "clean" suffix and should I do something about it? 5. Does NiceHash QuickMiner overclock my cards by default? 6. How can I limit CPU mining to less cores/load? 7. Does having display connected to the video card have any effect on performance? 8. Why is my speed changing up and down constantly? 9. When I exit NiceHash QuickMiner, are my overclock and fan settings restored?

Answers:

1. Why is NiceHashQuickMiner started with administrator privileges?

Administrator privileges are needed for overclocking. MSI Afterburner (which you'd not need anymore) is started with administrator privileges aswell. Since up to 20% extra performance is possible to achieve with up to 50% reduced power load, we do not believe it is smart to mine without adjusting clocks and power limits which require administrator privileges.

2. What happens when DAG is being generated?

Excavator would set memory overclock to 0 for the time DAG is being generated. This is done to prevent generation of corrupted DAG which causes all future shares to be invalid. Note that this feature only works if you set your overclock with Excavator and it DOES NOT work when using MSI Afterburner for overclocking. With this feature you can clock your card higher and do not need to worry about corrupted DAGs because these cannot happen anymore.

3. Where can I see number of accepted and rejects shares?

You can see number of accepted and rejected shares by calling API method algorithm.list. Note that, to the contrary of other PPLNS pools, for NiceHash, these values are not important. The reason is, because each share has a certain value that may not be the same. NiceHash does not have a fixed difficulty but rather dynamic. Higher difficulty shares have higher value. Since NiceHash has a PPS payout scheme (pay-per-share), it is very important to know the value of the share (share at twice the difficulty is worth twice as much BTC). If you chart down shares with their values, you get accepted/rejected speed. These charts are already available at NiceHash - Rig Manager. Other pools often display accepted speed on their charts as the value that the miner is reporting to the pool - and this value can be cheated-out (sending some extreme large value for example). NiceHash does not support speed reported by miner, rather it calculates accepted/rejected speed out of your shares. Thus, contrary to the other pools, these charts have very high value as they represent direct performance of your miner and your mining payouts are based directly on that.

4. Why do some jobs have "clean" suffix and should I do something about it?

Short answer: No, you cannot do anything about it and it is completely normal. Sometimes there will be more, sometimes there will be less of these jobs.

When job has "clean" suffix, it means that miner needs to drop current job immediately and start working on the new job - all previous work is not valid anymore and would result in a rejected share (job not found - stale share). One of the miner qualities is defined by the amount of how much time it takes for it to drop current job and start working on the new one. The time in between receiving new clean job and start working on the new job is wasted as these found shares always result in rejection as stale shares. This quality is not visible by the reported hashing speed but rather as a calculated speed on server side (NiceHash - accepted speed -> your actual profitability) or rather amount of stale shares (also your high latency to server increase amount of stale shares). Excavator has this switching time in between 1-3 milliseconds on modern CPUs of latest generation (Intel 10th gen, AMD Ryzen, Threadripper). It can be also observed and calculated from logs (when full detailed logging with -f 0 is enabled). This task is not so simple to optimize, because NVIDIA kernel launches are non preemptive, which means, once kernel is started, it cannot be terminated. Unfortunately, time-short kernel result in reduced speed because time is wasted managing kernel launch and finish. So, usually a certain balance is needed so that kernels do not take too long and cause a lot of wasted tame when jobs are switched and that also don't last too short time to waste mining time due to excessive kernel launch management. Of course, any miner developer can use various tricks to solve this issue and it is not only about tweaking these two values. Anyway... this is off topic now already. Back to "clean" jobs.

When job is not "clean" it means that miner does not have to drop current job, because previous job is still valid. Therefore when you see a job that isn't "clean" you know that it won't reduce your miner speed consequently. Excavator is made to simply ignore non-clean jobs (these only get printed out, but that's all).

So, now you want to get only jobs that are not clean, because then your miner does not have to be interrupted and you get higher performance. You do not have any control over that - NiceHash servers are sending jobs and these depends on buyers of hashpower.

5. Does NiceHash QuickMiner overclock my cards by default?

NO! There is no overclocking done without explicit command from the user.

6. How can I limit CPU mining to less cores/load?

By default, NiceHash QuickMiner starts XMRig with 50% load hint. This can be easily changed to 100% or any other number in nhqm.conf by modifying extra launch parameters and providing hint for whatever load you wish. If you provide 25, then XMRig will try to load 25% of your CPU, 50 then 50% etc.

...
"CPUMinerELP":"--cpu-max-threads-hint 50 --print-time 15",
...

7. Does having display connected to the video card have any effect on performance?

Yes! When you have display connected to a GPU, there is some performance penalty and your GPU will not hash with max possible speed. How much you lose depends on many factors such as number of displays connected, output resolution, number and intensity of various applications that utilize your GPU (NiceHash QuickMiner is not the only application utilizing your video card). Sometimes the performance penalty can be very minimal and perhaps even hardly to notice. But it can also be severe - 10%, 15% or even 25% of your max hashrate may be lost due to this fact. There are number of possible alleviations to make the penalty less severe:

• Use integrated GPU for rendering display.
• Turn off visual effects in Windows.
• Turn off Hardware acceleration in applications that use GPU such as Website browsers.
• Turn off/disable unneeded applications that utilize GPU.
• Reduce resolution and/or refresh rate.
• Reduce number of displays.
• Turn on Hardware-accelerated GPU scheduling.

8. Why is my speed changing up and down constantly?

Consider following facts:

• For RTX 3080 and 3090 VRAM temperatures have big effect on your hashing speed. When temperature of GDDR6X VRAM goes above 80, there are already signs of slight throttling which gets much more intense over 105 and extreme when it approaches 110 degrees Celsius. Make sure to properly cool your VRAM to avoid this issue.

• Is your card connected to the display? Resolution, refresh rate, number of monitors, activity on display, hardware acceleration (enabled/disabled)... are all the factors that affect your hashing speed. Excavator is made with mining set to low priority, so you can do various tasks on your PC and you do not notice any lag or jitter. If you want high speed on your primary video card then close all windows and just leave it be - you will see how hashing speed climbs up to the max. If you can afford it (you do not need high processing power for primary display output), you should switch display to be rendered by integrated GPU.

• Your actual speed in Rig Manager may dance up and down - that is normal. Check accepted speed over longer period of time (6 hours or more) and it should average out to your speed reported by the video card. You can read more about this here.

IMPORTANT For possible solution/improvement check this tip.

9. When I exit NiceHash QuickMiner, are my overclock and fan settings restored?

Yes. If you either apply OPTIMIZE profiles or set custom overclock using OCTune, after you exit NiceHash QuickMiner, the overclock settings and fan profile settings are restored to previous values before NiceHash QuickMiner was launched.