Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 5 Sep 2013 05:08:11 +0100
From: Rafael Waldo Delgado Doblas <lord.rafa@...il.com>
To: john-dev@...ts.openwall.com
Subject: Re: Parallella: Litecoin mining

Hello Alexander,

2013/9/4 Solar Designer <solar@...nwall.com>

> I don't know what you mean by "the work is discarded" here.  What
> component do you think discards the work, and why?
>
> You should get your modified cgminer to run to a point where the pool
> does accept a share.
>

I mean that if there is a block found on the network, the miner stops
working on old data and begins to hash the next block. I'm getting a lot of
longpolls then is it possible that cgminer never finds a share because
doesn't mine fast enough?.


> Wrong conclusions.  Please re-read:
>
> http://www.openwall.com/lists/john-dev/2013/08/29/4
>
> "Slow" is non-informative.  IMADD has high latency (you'd call this
> "slow"), but it also has high throughput (we may call this "fast").
> This means that with proper instruction scheduling it can be fast.  When
> you use inline asm for just one rotate operation, you make the IMADD and
> its latency opaque to gcc.  As a result, gcc is not enabled to produce
> good instruction scheduling.  Additionally, your use of just one
> register for the temporary value does not allow for multiple rotate
> operations to overlap (mixing their instructions), but clearly with this
> inline asm approach gcc would not perform this optimization anyway
> because, once again, the piece of inline asm is opaque to it (as far as
> gcc is aware, it's just a string, not a piece of code that gcc could
> possibly inter-mix with another piece of code).
>

Sorry I didn't know it I will work on this. The current performance is 0.9
Khash/s

Today I use the option -mfp-mode=int to set the mode and the instructions
IMADD started to work as supposed to do. I fix a couple of bugs that I
found and now everything looks fine. Also I implemented a better way to
check if epiphany scrypt works fine, just compile with EPIPHANY_TEST
defined.

Regards,
Rafael.

[ CONTENT OF TYPE text/html SKIPPED ]

Powered by blists - more mailing lists

Your e-mail address:

Powered by Openwall GNU/*/Linux - Powered by OpenVZ