kingpincooling.com

Go Back   kingpincooling.com > Overclocking & Benching > Shamino's Lair...

Shamino's Lair... The one, the only, the master; Shamino...

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 05-16-2010, 06:36 PM
TiN's Avatar
TiN TiN is offline
Happy engineer
 
Join Date: Jan 2010
Location: Taipei
Posts: 1,217
Send a message via ICQ to TiN Send a message via Skype™ to TiN
Talking [EE] Untouchables Rev0.0 : usage

I hope Shammy would not mind if this thread appear. If any issues with it - feel free to delete, I would not publish any non-public data about these stuff on purpose, thats for sure.

So I've received my sample after month of customs clearing, and now doing first steps with it. So most things described here by me are lame, stupid and beginner trash. Hope things will clarify in future and i will get new knowledge later

I've assembled next rig:

i7 920 stock, box cooler
ASUS P6T Dlx reflashed to P6T6
3x1GB DRAMs
Reference GeForce GTX 285
Shammy's Untouchables, set to initial voltage 1.2V & 2.37V
FIVE "Pci-express" power connectors for VGA hooked to Enermax Revo 1250W
Kingpincooling.com Tek9 6.66 LN2 pot

As for tools: I've used:

Fluke 87V DMM
Tektronix 2246-Y 100MHz scope
xDevs.com ES HC1 device prototype for digital control to Untouchable
xDevs.com VARM 2-channel voltage meter

-----------------
Please take a notice, that I've previously used external VRMs on VGA's, so
had some positive and successful experience from that kind of things.
I've tried and benched:

1st: 7800GTX + 2-phase + 1-phase uPI-based VRM from radeon 4850
2nd: 8600GT + same radeon 4850 VRM
3rd: 9500GT + same radeon 4850 VRM
4th: GTX285 + GPU powered from mixed Volterra 1165MF 3-phase VRMs from 4870X2

And now...



I think k|ngp|n should now know how real Tek9 6.66 look like :-D
Better is only FAT pot with untouchabled GTX480 maybe



I've hooked extra VRM with usual technique, removing stock chokes and putting volts from external VRM into power plane inputs. Now I used 7 solid copper wires for VGPU power and 3 same wires for Vmemory power.
I've never used such type solid copper wires, only thick "audiophile-type" multiwired cables with thick insulation.



Also 10 GND wires was used as interconnect. I've hooked 2-channel voltage meter to out pads on EVGA card.
Videocard have added tantalum capacitors on memory and core VRM, just in points where wires joints.
Ripple and noise was measured by oscilloscope probe on these capacitors pads.



The untouchables was cooled by high-cfm 80mm fan, and VGA NVIO area was cooled by 120mm fan. I've used LN2 pot with temps -20 to -70C, because it's the only cooler i have now, that fits this card. Further testing will be done with chiller unit.



All PCI-E power connectors was populated with cables from single Enermax Revolution 1250W PSU. TWO was hooked to VGA itself and three for EVGA VRM.

Total look w/o fans:



Before going windows with this rig, i've applied 1450mV voltage for main 10-channel power VRM.
It was done digitally from my ES device, I think same way as EVbot does.
So, i've booted and run 3dmark03 nature, on stock clocks for VGA and 1

Idle volts:



Load volts:



Drop of voltage is huge, almost 100mV. I think I should use much more wires for such type of VGAs. And maybe better use multiwire cables, to reduce impedance and skin-effect?

During test and transients I've noticed high-pitched noise from VRM (usual stuff) and heavy horisontal bars flickering fast on screen. Tried to capture that with next photo. Horisontal lines more visible with heavy loads, and less with lighter, but present always in any 3D test and appear even during 3dmark03 loading in windows.



With lower volts (stock for GTX285 are near 1.1V), e.g. 1.25V card could not even do GT1 of 3d03.
It halts like this:



Then I powered on my scope to see what happen on power lines.

During idle everything was very nice.



20mV peak-peak ripple, it's very good. My stock GeForce 8800GTX have 70mV peak-peak idle noise.

Then I've run Nature from 3d03. On stock clocks, and 1.45vgpu and 2.3Vmem applied from EVGA The Untouchables.

VGPU line:



VMEM line:



Remember, these signals was aquired directly from bulk tantalum capacitors (total capacitance >3200uF VGPU, >1000uF Vmem) placed nearby stock VRM chokes location on VGA PCB.

OMG, Is what i say during test. 0.6V peak-peak noise is more than enough to forget about any overclocking completely
Memory was not better, 336mV peak-peak noise.

So looks like i have new experience.

Ideas to do next time:

1. Add large bulk electrolyte capacitors as close as possible to memory chips and gpu.
2. Triple amount of wires from VRM to VGA PCB.
3. Use multiwire cables for interconnect, not solid copper ones.
4. Add oscilloscope probe connection input directly below GPU on bottom side of VGA PCB, for most accurate measurement.

If nothing help then

5. Ask Shammy for help stupid Tinny

When I've used Radeon 4870X2 Volterra VT1165MF-based VRMs image from this GTX285 didn't flicker, and there was no such big noise. But I've used my own wires during that tests:



Also there was more caps (extra electrolytic 4x1000uF 4V and 2x680 6.3V's)



P.s. thanks for watching for those who saw my livestream session with this stuff.
__________________

Last edited by TiN; 05-16-2010 at 06:44 PM.
Reply With Quote
  #2  
Old 05-16-2010, 08:20 PM
Shammy Shammy is offline
Liquid Nitrogen
 
Join Date: Aug 2009
Posts: 848
Default

due to the distance away there will definitely be droop , you have to tune volts to the load volts.
connect vsense + and vsense - to the actual gpu +/- behind the gpu core will also help.

i prefer the solid wires, if all your current on MB / VGA uses this to flow to the core in your inductors, they work good and always have

the solder joints doesnt seem thorough, you did scrape off insulative layer?, maybe front and end both add solder?

Last edited by Shammy; 05-16-2010 at 08:28 PM.
Reply With Quote
  #3  
Old 05-16-2010, 09:56 PM
Hondacity's Avatar
Hondacity Hondacity is offline
Worries Too Much About User Title
 
Join Date: Oct 2009
Posts: 405
Default

are the solid cables insulated?

extra low esr polymer caps around 5mohms might help...

what tantalum caps are you using? looks like kemet stuff... got specs of it?
Reply With Quote
  #4  
Old 05-17-2010, 01:12 AM
Raja@ASUS Raja@ASUS is offline
Dry Ice
 
Join Date: Sep 2009
Posts: 288
Default

The cable is polyestermide/polyurethane insulated - so needs scraping slightly. Maybe bad joints. Multi strand wire won't help really (i don't think skin-effect is causing any kind of problem). I have my UT half connected up to a board here, when i get time I'll complete the mod and see what happens.

Later
Raja

Last edited by Raja@ASUS; 05-17-2010 at 01:19 AM.
Reply With Quote
  #5  
Old 05-17-2010, 05:43 AM
TiN's Avatar
TiN TiN is offline
Happy engineer
 
Join Date: Jan 2010
Location: Taipei
Posts: 1,217
Send a message via ICQ to TiN Send a message via Skype™ to TiN
Default

Shammy

Quote:
connect vsense + and vsense - to the actual gpu +/- behind the gpu core will also help.
Vsense+ and Vsense- are that lines where VR-mod on masterchip?

I've scraped both ends, but now see I could do work better. Anyway, will add more multistrand wires (thanks for word, Raja, I speak english not natively for now )
__________________
Reply With Quote
  #6  
Old 05-17-2010, 09:34 AM
Raja@ASUS Raja@ASUS is offline
Dry Ice
 
Join Date: Sep 2009
Posts: 288
Default

Quote:
Originally Posted by TiN View Post
Shammy



Vsense+ and Vsense- are that lines where VR-mod on masterchip?

I've scraped both ends, but now see I could do work better. Anyway, will add more multistrand wires (thanks for word, Raja, I speak english not natively for now )
No problem. I think if you add more wires it will help.
Reply With Quote
  #7  
Old 05-19-2010, 07:54 AM
TiN's Avatar
TiN TiN is offline
Happy engineer
 
Join Date: Jan 2010
Location: Taipei
Posts: 1,217
Send a message via ICQ to TiN Send a message via Skype™ to TiN
Default

Added more wires. Situation improved twice.
Now addin even more

Sham, what about my #5 post? Hook feedback line to that points (where VR suggested)?

I DMMed them, one seems Vcore, second GND, but want to be sure with these volterras.

UPDATE:

Testing done.

Ripple on memory voltage (measurement same point, VRM out capacitor on VGA PCB) reduced from ~300+mV to near 90-120mV. It's now acceptable (as stock VRM on such cards).
Ripple on core voltage improved from ~600mV shi(f)t to mere 200-220mV on stock clocks and 1.4V (dropping to 1.33-1.36) and 240-260mV with 850MHz clocks and near zero GPU monitoring temp.

Horisontal banding flicker still exist under load, by looks like less?

MUCH better
Besides adding wires, i've also added caps, 2 x 1000uF 2.5V chemicons, 680uF chemicon, 2700uF 6.3V MFZ for core. For memory added 3300uF 6.3V KZE and 2700uF 6.3 MFZ.

Ramped Vmemory to 2.4V as my friend Vince told me.

Now card ABLE to do 850/1440MHz with near zero temp. NO WAY it was possible with stock VRM, even with -140C GPU temp. Instant halt in 3D with such core and memory clocks together.

Will do insulation on card, hook up MAGNUM pot to my CPU (920), and see how it go. If things go up, i will test this card with some hexcore this weekend (and maybe QHEX+REX for 3d01).

Pics:

Solder works





back



Banding. These horisontal lines should not be there



Memory ripple:



Passed nature at 848/1944/1440 with +14C monitoring temp



Ripple and volts during test



Ripple with 900MHz test (frozen in middle of test, but that because temp too high, i guess, near +10C)

__________________

Last edited by TiN; 05-19-2010 at 09:11 AM.
Reply With Quote
  #8  
Old 05-19-2010, 09:33 AM
cyclone's Avatar
cyclone cyclone is offline
Ambient
 
Join Date: Jan 2010
Posts: 5
Send a message via ICQ to cyclone Send a message via Skype™ to cyclone
Default

Damn long wires for that current loads :/
Reply With Quote
  #9  
Old 05-19-2010, 02:42 PM
carpo93 carpo93 is offline
Sub-Ambient
 
Join Date: Aug 2009
Posts: 94
Default

saw you on live broadcasting, very nice equipement you got there
Reply With Quote
  #10  
Old 05-20-2010, 05:13 AM
Raja@ASUS Raja@ASUS is offline
Dry Ice
 
Join Date: Sep 2009
Posts: 288
Default

Try some HF (MLCC bypassed with silvered mica in picofarad range) decoupling after the wires on the card side Tin - maybe the banding is due to noise pickup in the high KHz region.

Last edited by Raja@ASUS; 05-20-2010 at 04:06 PM.
Reply With Quote
Reply

Tags
even more crazy stuff, r&d


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:26 PM.

Contact Us - www.kingpincooling.com - Archive - Top
Powered by vBulletin® Version 3.8.3 Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.