+1

these boards are actually quite interesting/strange to work with. I had a poor performance chip recently start working almost like new (went tfrom effective 0.4GH to 1.7GH). These boards can be modified for 40% gains with good airflow and some small heatsinks (~35Ghash) and annecdotal reports indicate that the chips can handle some heat and the converter presumably has even more headroom.

i would not be surprised if october h-boards were manufactured to run at 30GHash by default

Im using bitminter with difficulty of 16 for a starter and it works great. The card has a hashrate of 36.5GH  with the noncerate (and pool reported) being 33.25GHash.
help requested:

1) chip 6 is producing a few miso-errors (about 4%) plus the same number of hardware/stale errors. its pretty low, and only 2 other chips report miso-errors (1% and 2% rates). should i be concerned/fixing this?
2) a chip (varies time to time) has stopped a few times recently, usually in the first 5 minutes from reboot (if they start at all). Its running okay now after using stop miner/start miner via web gui, but is there a known reason for the issue or a solution? the chip is manually tuned at 54?
3) when tuning, what error rate should we go for to get the best result? Generally, ive tuned anything with <10% to run at 55, and over 10% i tuned to 54 or even 53. In most cases, tuning down to 54 seems to barely increase the effective noncerate from the drop in both hashrate and error rate. Is 10% errors a good threshold for tuning, or should i use lower (ie 5% or maybe 7%)?

The card is cooled somewhat aggressively, with tiny heatsinks on each chip (same size as chip) plus 5 slightly larger heatsinks (about 4x the surface area) centered on the back of the board, opposite the capacitor banks (that way, each sink is centered for the 4 nearest chips). a 120mm fan is aimed normal to the board about 5" away. nothing gets hot, just reasonably warm

I tuned down to 1.165k, getting around 35Ghash, and 33Ghash/noncerate at the pool. Amazingly, chip #13 which was running at ~300mhash with tons of errors now works just fine.

watch bitfury. they have some good headroom to overclock and are power efficient enough to battle many gen2 designs

it did, haha! Id love to get a few of these, but the price needs to be slightly lower i think, more in line with ~0.65 BTC for orders of 10+

if the 30A converter is the limiting factor on chip power (presumably up to about 0.84V), does setting a poor-performance chip (<0.6Ghash) "free up" ~6% more power headroom for the other chips to use? (for example, pushing them to 0.88V with added cooling)

i noticed that in the last 2 days at some point they changed the accounts page and removed the ability to set a difficulty. perhaps that is related?

hey what pool(s) are people using for bitfury?

Slush's is my [previous] preference, and has a 30day luck >100%
Bitminter has fewer fees + namecoin (this is about a 4% bonus, correct?), but the luck recently has been around 90%

my slush pool with bitfury is reporting only about 1000Mh per worker (3Ghash) why?

did the accounts page just get modified? I no longer see any namecoin info, and it does not seem to show the difficulty/suggested difficulty anymore...?

^That looks good

what sort of heatsinks, tiny individual ones or larger plate(s)?

1       AIfDSo  55      1.532   1.807   107     5       0       0       171    $
2       AIfDSo  55      1.890   1.871   132     8       0       0       177    $
3       AIfDSo  55      1.747   1.807   122     7       0       0       171    $
4       AIfDSo  55      1.460   1.691   102     14      0       0       160    $
5       AIfDSo  55      1.417   1.829   99      14      0       0       173    $
6       AIfDSo  55      1.518   1.797   106     3       0       0       170    $
7       AIfDSo  55      1.661   1.871   116     14      0       0       177    $
8       AIfDSo  55      1.546   1.733   108     16      0       0       164    $
9       AIfDSo  55      1.947   1.850   136     8       0       0       175    $
10      AIfDSo  55      1.904   1.871   133     6       0       0       177    $
11      AIfDSo  55      1.718   1.776   120     13      0       0       168    $
12      AIfDSo  55      1.589   1.744   111     12      0       0       165    $
13      AiFDso  55      0.172   0.486   12      11      0       0       46     $
14      AIfDSo  55      1.603   1.797   112     5       0       0       170    $
15      AIfDSo  55      1.632   1.765   114     8       0       0       167    $
16      AIfDSo  55      1.475   1.755   103     10      0       0       166    $
speed:825 noncerate[GH/s]:24.811 (1.551/chip) hashrate[GH/s]:27.449 good:1733 e$
0:      825     24.811  27.449  1733    154     0       0       15      1      $

suggested tweaks? Obviously #13 is a poorly performing chip, should i disable it?

yeah, downloaded the full image, redid the SD card, edited the ip setting using VMware ubuntu system and the following:

sudo sed -i 's/10.10.11.249/192.168.1.249/' etc/network/interfaces
sudo sed -i 's/255.0.0.0/255.255.255.0/' etc/network/interfaces
sudo sed -i 's/10.1.1.1/192.168.1.1/' etc/network/interfaces

bitfury page reports 25ghash +/-2    and im waiting to see how slushs pool handles it

got the full image now, and am working at 15+ Ghash and climbing. ill report back once it stabilizes at slushes pool

up and running now   15Ghash and climbing

on further inspection, it seems dropbox connection got lost mid-download, resulting in what appeared to be a full .img file but only 1.6GB. Ive redownloaded and now have a 3.63GB file that is formatting now. crossing my fingers.

perhaps a secondary upload location (particularly with the 'correct' ip settings) would be a good idea?

well i finally got a liveusb ubuntu going, sudo edited the ip fields (confirmed with explorer) and no luck. wiped the card and reinstalled the image with the bad ip - still no luck.

i am re-downloading the image as a final resort, but this is really starting to bug me...

edit: looks like i cant get a stable download. my first image file was only 1.6GB (expanded to about 3.69GB on the SD) and my re-download 'completed' at only 548mb. whats up with that? can someone post a different link maybe?

I redid it twice now. my card appears to be supported for use (PNY 8GB microSDHC 10), and i am using win32diskimager

its all about the resale for these, personal use will never turn a profit sadly.

I bought 8 of them for about 1.3 BTC (after tax, shipping, etc), and just resold 3 of them for a total 0.8 BTC, putting me at a relative cost of 0.1BTC per unit i still have. These have each mined almost 0.01BTC and are still up for sale

bringing my tech problems back to this thread (i got some fast replies last time):

i got a monitor and keyboard now to manually get the rpi running, and cannot even login.

It appears to load the entire code, and gets to

"(none) login:"

I enter pi as the username and get this response:

"unable to determine your tty name.
Debian GNU/Linux 7 (none) ttyl

(none) login: "


whats going on?

ps: i apologize for harassing multiple threads. the bitfury US guide thread is the best place to reply, i just want to get my error seen so that someone can help me fix it. Its been over 24hrs that ive been unable to mine with my bitfury system because of this

bringing my tech problems back to this thread (i got some fast replies last time):

i got a monitor and keyboard now to manually get the rpi running, and cannot even login.

It appears to load the entire code, and gets to

"(none) login:"

I enter pi as the username and get this response:

"unable to determine your tty name.
Debian GNU/Linux 7 (none) ttyl

(none) login: "


whats going on?