ZTEX voltmod

[rupy]

@nyana Did you get around to mod all your FPGAs?

[Andows]

What voltages have you guys ended up using on long term? Have you experienced any hardware failures or performance degradation?

Xilinx suggests (in the Spartan-6 FPGA Data Sheet: DC and Switching Characteristics -document) using 1.14-1.26V for V_CCINT and lists the 1.32V as absolute maximum.
I suspect that 1.26V would probably be the safest maximum for long-term use, but I would love to hear more about your experiences.

[nyana]

@ rupy: not yet...

@ Andows: Im on 1,34-1,36v - no temperature issues, no stability problems, ~240-248MHZ

[kakobrekla]

Been runin at 1.4v for weeks now... 

[rupy]

@ rupy: not yet...

@ Andows: Im on 1,34-1,36v - no temperature issues, no stability problems, ~240-248MHZ

Why not? Is there something your not satisfied with?

I'm really considering doing this since it's not much left of 50 BTC blocks... can just revert to lower voltage after!

[nyana]

@ rupy

working ~65 hrs a week atm and building a house too...not much time for "btc-work".

2-ztex modded today...

[goligo]

I tried the voltmod today on my 1.15y. Works like a charm. Went from 216 to 232 after raising the voltage to 1.32V. Also tried 1.4V for a short time, which gave me

001-0: ztex_ufm1_15y1-04A36E42D1-4: f=248.00MHz,  errorRate=0.00%,  maxErrorRate=0.00%,  hashRate=248.0MH/s,  submitted 13 new nonces,  luckFactor=0.66

Now I am thinking about watercooling, also because of the noise reduction and about recompiling BTCMiner to allow higher frequencies ;-)

[BR0KK]

I think of water cooling my boards as well

I have a simple NB cooler from Watercool called "HEat killer - Micro" here that would fit.