Difficulty > 1 share adoption suggestion for pool operators. - page 2.

racerguy

sr. member

Activity: 270

Merit: 250

Quote from: kano on June 22, 2012, 08:12:06 AM

Quote from: Meni Rosenfeld on June 22, 2012, 08:01:08 AM

Perhaps this is a good opportunity to review sections 7.5 and 7.6 of AoBPMRS. Having different difficulty shares for different miners is fairly straightforward from the reward method perspective.

Quote from: kano on June 22, 2012, 06:57:46 AM

Will be interesting to see the affect on stale shares - since each stale is worth n times what they were before.
e.g if your difficulty goes up 10 times but your stale rate doesn't go down 10 times, you lose by having a higher difficulty.

Stale rate is measured as a percentage, and as long as the percentage remains the same it doesn't matter what difficulty the share are.

And, the share difficulty should have absolutely no effect on the stale rate.

Except that with higher difficulty it takes longer to find a share thus the amount of work lost due to a stale increases ......
So no.

mathfail

kano

legendary

Activity: 4592

Merit: 1851

Linux since 1997 RedHat 4

Quote from: Meni Rosenfeld on June 22, 2012, 08:01:08 AM

Perhaps this is a good opportunity to review sections 7.5 and 7.6 of AoBPMRS. Having different difficulty shares for different miners is fairly straightforward from the reward method perspective.

Quote from: kano on June 22, 2012, 06:57:46 AM

Will be interesting to see the affect on stale shares - since each stale is worth n times what they were before.
e.g if your difficulty goes up 10 times but your stale rate doesn't go down 10 times, you lose by having a higher difficulty.

Stale rate is measured as a percentage, and as long as the percentage remains the same it doesn't matter what difficulty the share are.

And, the share difficulty should have absolutely no effect on the stale rate.

Except that with higher difficulty it takes longer to find a share thus the amount of work lost due to a stale increases ......
So no.

organofcorti

donator

Activity: 2058

Merit: 1007

Poor impulse control.

Increasing D for pooled share submissions would increase variance for miners.

The variance in time between share submissions at a constant hashrate will increase by the square of the ratio of the greater difficulty to the lesser one. Increase D from 1 to 10 and the variance of the time in between share submissions increases one hundred fold.

Meni Rosenfeld

donator

Activity: 2058

Merit: 1054

Perhaps this is a good opportunity to review sections 7.5 and 7.6 of AoBPMRS. Having different difficulty shares for different miners is fairly straightforward from the reward method perspective.

Quote from: kano on June 22, 2012, 06:57:46 AM

Will be interesting to see the affect on stale shares - since each stale is worth n times what they were before.
e.g if your difficulty goes up 10 times but your stale rate doesn't go down 10 times, you lose by having a higher difficulty.

Stale rate is measured as a percentage, and as long as the percentage remains the same it doesn't matter what difficulty the share are.

And, the share difficulty should have absolutely no effect on the stale rate.

-ck

legendary

Activity: 4088

Merit: 1631

Ruu \o/

It's also worth mentioning this would make things very interesting for the proxy pools out there if they start passing work to pools set up for higher difficulty shares Wink

-ck

legendary

Activity: 4088

Merit: 1631

Ruu \o/

Quote from: kano on June 22, 2012, 06:57:46 AM

Will be interesting to see the affect on stale shares - since each stale is worth n times what they were before.
e.g if your difficulty goes up 10 times but your stale rate doesn't go down 10 times, you lose by having a higher difficulty.

Indeed, back to that chance debate I've seen many times before in different forms. Whether the random nature of shares scattered about and when they fall relative to block changes will even out compared to many many small shares. Mathematically to me it would seem to be exactly the same as current shares based on chance: It will fluctuate visibly more but even out long term to be identical.

kano

legendary

Activity: 4592

Merit: 1851

Linux since 1997 RedHat 4

Will be interesting to see the affect on stale shares - since each stale is worth n times what they were before.
e.g if your difficulty goes up 10 times but your stale rate doesn't go down 10 times, you lose by having a higher difficulty.

Graet

vip

Activity: 980

Merit: 1001

We have been discussing higher diff shares going forward
Initially we will offer miners a choice of 2 difficulties.
Over time we will code up some way to do dynamic difficulty as suggested and ensure payouts work correctly with dynamic share difficulties

-ck

legendary

Activity: 4088

Merit: 1631

Ruu \o/

With the upcoming HUGE hashing hardware starting to hit, now would be a good time to consider supporting higher than 1 difficulty shares for bigger miners which would allow pools to scale without as much increase in bandwidth and server resource requirements as the increase in hashrates. I'd suggest initially making an optional difficulty multiplier switch for workers on the website, which would scale with the miners' hashrate. Enabling it by default would surprise and confuse many miners, and also some mining software may not support it so they'll just get high rejects unexpectedly. As a rough guess, I'd recommend increasing difficulty by 1 for every 1GH of hashing power. This will not dramatically change getwork rates, but it would change share submission rate and processing of them which is bandwidth and CPU intensive. There would be issues with fluctuating hashrates and difficulty targets when precisely on the 1GH boundaries, and this could be worked around by the user setting their own target or by using some hysteresis for the change up and down of targets to avoid frequently flicking between difficulties.

Topic: Difficulty > 1 share adoption suggestion for pool operators. - page 2. (Read 3712 times)