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Topic: ZTEX voltmod (Read 5044 times)

hero member
Activity: 784
Merit: 500
September 20, 2012, 04:29:56 PM
#28
I think of water cooling my boards as well Smiley

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

newbie
Activity: 25
Merit: 0
September 19, 2012, 07:07:16 PM
#27
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 ;-)
member
Activity: 81
Merit: 10
August 31, 2012, 01:29:40 PM
#26
@ rupy

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

2-ztex modded today...
hero member
Activity: 725
Merit: 500
August 27, 2012, 12:02:18 PM
#25
@ 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!
hero member
Activity: 714
Merit: 500
Psi laju, karavani prolaze.
August 27, 2012, 11:16:43 AM
#24
Been runin at 1.4v for weeks now...  Smiley
member
Activity: 81
Merit: 10
August 27, 2012, 07:48:28 AM
#23
@ rupy: not yet...

@ Andows: Im on 1,34-1,36v - no temperature issues, no stability problems, ~240-248MHZ
newbie
Activity: 3
Merit: 0
August 27, 2012, 05:39:12 AM
#22
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 VCCINT 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.
hero member
Activity: 725
Merit: 500
August 01, 2012, 02:30:18 PM
#21
@nyana Did you get around to mod all your FPGAs?
legendary
Activity: 2128
Merit: 1065
July 29, 2012, 05:07:38 PM
#20
is it possible to messure the temperature of the chip?
Not directly. But when push comes to shove people do this by building some sort of multivibrator circuit involving the I/O pads and external analog components. Then the temperature can be measured indirectly by counting up the time it takes for some capacitor to charge/discharge through some internal resistance. Calibration can be difficult for such circuits.
hero member
Activity: 784
Merit: 500
July 29, 2012, 04:29:09 PM
#19
As far as i know they dont have an Inbuild temp Sensor.
legendary
Activity: 2856
Merit: 1518
Bitcoin Legal Tender Countries: 2 of 206
July 29, 2012, 09:09:05 AM
#18
is it possible to messure the temperature of the chip?
hero member
Activity: 714
Merit: 500
Psi laju, karavani prolaze.
July 29, 2012, 07:55:51 AM
#17
Quote
Can't you just unsolder the R13 and replace it instead of all these ghetto cables?

You can, but having the ability to fine-tune and change voltage on the fly is very handy.
And by using a big multiturn VR in parallel with the existing R, you can tune the voltage very precisely. (I also have off/on switch).

Quote
Can you bump it to 1.320v without adding heatsinks etc.?

Prolly yes, depends on the ambient temp, HS-chip contact, etc...

Quote
What are the specs of the trimmer ?

I started with 50k VR, but then I broke one pin and changed it to 25k VR + 3k R. I'd recommend at least 25k or higher.
legendary
Activity: 1022
Merit: 1000
BitMinter
July 29, 2012, 01:48:29 AM
#16
What are the specs of the trimmer ?

Edit: Found above Tongue
hero member
Activity: 725
Merit: 500
July 28, 2012, 07:17:36 PM
#15
Can't you just unsolder the R13 and replace it instead of all these ghetto cables?

How much warmer does the chip become? Can you bump it to 1.320v without adding heatsinks etc.?
legendary
Activity: 924
Merit: 1004
Firstbits: 1pirata
July 28, 2012, 08:18:22 AM
#14
hero member
Activity: 714
Merit: 500
Psi laju, karavani prolaze.
July 28, 2012, 08:10:25 AM
#13
Nice work, nice pics Smiley
member
Activity: 81
Merit: 10
July 28, 2012, 07:24:35 AM
#12
Hey all,

the Voltmod works for me very well too.

I measured a deafult voltage of 1,23v on my "lazyest" ztex Module.

The Resistor R13 (2,4kohm) was original @ 885 ohms (dont know why and i dont know much about elecronics). after soldering the Trimmer i "regulated" it to 818 Ohms and a Voltage of 1,37.

The Results on 18 degree Celsius

Stock:
1,230v / 204mhz / 885 Ohm@R13 / 0,10% Error

Modded:
1,375v / 240mhz / 818 Ohm@R13 / 0,00% Error

Im very happy with these results, after a few days of testing i will mod all my 22 ztex Modules!

attached some Pics from "work"


By daki123 at 2012-07-28

By daki123 at 2012-07-28

By daki123 at 2012-07-28

By daki123 at 2012-07-28



hero member
Activity: 784
Merit: 500
July 24, 2012, 05:25:08 PM
#11
Anny extremcooling attempts planed. Like dry ice or ln2 Cheesy?
hero member
Activity: 714
Merit: 500
Psi laju, karavani prolaze.
July 24, 2012, 05:20:12 PM
#10
I just love me some ghetto modding!!!  Congrats mate. Grin

My tex doesn't look that ghetto anymore after seeing this :p




A little update on the tex. Ran 276 mhash at 1.48v with TML (X:276 C:182,182,188) today with minimal invalids. Next step is to mount a waterblock on in and try to go past 1.5v.
rph
full member
Activity: 176
Merit: 100
July 02, 2012, 01:10:28 PM
#9
And Xilinx told me that 45nm performance was not strongly voltage-sensitive.. Roll Eyes

-rph
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