Update: LukSticks, and Higher Perf…

Good news up front

1. I finally made some new luksticks (I’ll write about that separately), and
2. I managed to get quite a good performance boost for v4r last night
   (from 1700ish to 2200ish on my 7210, and from 1900ish to 2350ish on my 7250)

Man, what a day, yesterday.

First had a long, gruelling long hike with my dogs, and thought I could hardly lift a finger after that any more, I did finally get in the mood of locking myself in my with 7250 workstation and doing some serious coding (because with the lukSticks finally done – see below – I finally did have some time left to do that!).

Locked myself away from everybody else, got some uninterrupted coding time (oh, so rare), and got to work. Got on a roll, finally found the time to do a lot of the code re-orgs that I’ve been talking about for ages – much better vectorization – and managed to constantly chip away on hash rate, one instruction at a time. In fact, that entire process worked so well that I eventually worked way into the night (it’s so hard to stop while more perf seems to lie around the corner!) until finally, at about 1am I called it a day (or called it a night?) – having manged to bump performance on my 7250 workstation from about 1900H/s to nearly 2400. Wonderful. Now just build a release, quickly test it on my 7210, and finally get to bed.

Not so. First, building the release took a while, so I had to stay up til about 2 watching the build to run through – which, when dead tired and at 2am – is about as thrilling as watching paint dry…. in particular if it literally takes an hour.

But finally, release is done, so just quickly download onto my 7210 Asrock machine for final perf measurement (because most people on this blog are more interested in 7210s than in what my workstation can do!), then just write a quick note on the blog, and finally get to bed, after a nice and satisfying day’s achievement. Right?

Not so. Downloaded the baked release, put it on a lukstick, went to my garage, popped it in, booted …. and saw no difference. None. Nada. Zilch. Of course, first thought was “oh, those darn luksticks again – probably messed up the miner upgrade”… but no, miner shows new version number, just as it should. Still, no difference. Reboot, try again. Nothing. Try another node, same thing. Conclusion: Apparently all my work was for nothing – maybe it did work on a 7250, but not on a 7210? Argh. Went to bed, totally devastated. What a bummer.

Except. Of course, that story just didn’t make sense, it simply couldn’t be… and in fact, my wife had the right idea from the start, as soon as I whined about my experience this mornin: “maybe you still ran the old code, and it just wrongly showed the new version?”. Doesn’t sound plausible, except that’s exactly what happened: Since 7250s are not exactly the fastest at compiling and linking I do bake my releases on a different machine, so before doing that I have to commit and push on my workstation, then pull on the baking machine, bake there, and wait for the goodness to happen. And since I had forgotten to bump the version number before committing (yes, I was tired) I didn’t actually bump the version number until I was on the baking node – and since git had apparently had some conflict when pulling the latest release (which I had completely overlooked – yes, I was tired) I had never actually pulled the new code at all. So I did in fact bake the old code with the new version number. Yay. (If you learned anyhing: Don’t bake releases when you’re dead tired – it can wait a day).

Anyway – just had another look this morning after at least a few hours’ sleep; found the git pull that hadn’t gone through, baked a mini-release for testing, put that on a lukstick, and ta-daaa: 2200 H/s on my 7210. A second node I tested was slightly slower – say 2100 – but even that is a massive speedup over the 1700ish from just yesterday morning.

All in all, a few weeks ago we were down to less than 30 cents/kH at 1700 kH (the first v4r version even had less than 1kH/s!) …. and today, we’re up to 2200ish kH/s, and that at today’s nearly 50 cent kH … that’s quite a difference. $1/day is a far cry from the $20/day in the crazy times – but it sure beats 30 cents/a day!

Aaaanyway – that was a long story just to say: Performance is up! I’ll be doing some more testing soon, just to make sure that I didn’t accidentally disable CPU version, MPSS version, or other coins like haven again (I actually do that during development to keep compile times low…), and will then bake a “real” release. No more optimizing today – today will be all about testing, and releasing.

Anyway – it’s all good news; I’ll write a bit more about the new lukSticks, soon, too (and that was a real nightmare!), but for now, back to making this release!

With that – happy mining!