Overclock.net › Forums › Volt Mods › General Volt Mods › Graphics Cards Volt Mods › HD5870 Voltmod Issues...
New Posts  All Forums:Forum Nav:

HD5870 Voltmod Issues... - Page 2

post #11 of 19
IMO that voltage for the sapphire card on stock cooling is WAY too much. And you shouldn't need more than 1,3v for 950 on the clock

You could have controlled it's voltage throught sapphire TRIXX software, no need to pen mod it.

As for the XFX, I wouldn't flash it because you might actually damage the card if you flash it to a model that works completly different
post #12 of 19
ty cl3p thumb.gif
 
Thuban Powah!
(14 items)
 
 
CPUMotherboardGraphicsRAM
Xeon X5650 Asus P6X58D-E Sapphire HD 7950 G.Skill Trident-X 2600 CL10 
Hard DriveCoolingPowerCase
Samsung 840 pro Bong cooler / RASA waterblock Rosewill Capstone Gold 750 None 
MouseMouse PadAudio
cheap! Newegg box panel ibeats with onboard. 
CPUMotherboardGraphicsRAM
AMD Phenom II X6 1075T w/2 cores locked @ 4.2+ M4a89GTD-Pro XFX Radeon HD 5870 8gb Samsung ddr3 1600 11-11-11-28@ 8-8-8-24 
Hard DriveHard DriveOptical DriveCooling
OCZ Agility2 40gb WD Blue 500GB Lite-On RASA waterblock 
OSMonitorKeyboardPower
Windows & Linux Samsung 1080p 2 ms Dell Thermaltake TR2-800 
CaseMouse
Cooler Master Elite 330 (was) cheap 
  hide details  
Reply
 
Thuban Powah!
(14 items)
 
 
CPUMotherboardGraphicsRAM
Xeon X5650 Asus P6X58D-E Sapphire HD 7950 G.Skill Trident-X 2600 CL10 
Hard DriveCoolingPowerCase
Samsung 840 pro Bong cooler / RASA waterblock Rosewill Capstone Gold 750 None 
MouseMouse PadAudio
cheap! Newegg box panel ibeats with onboard. 
CPUMotherboardGraphicsRAM
AMD Phenom II X6 1075T w/2 cores locked @ 4.2+ M4a89GTD-Pro XFX Radeon HD 5870 8gb Samsung ddr3 1600 11-11-11-28@ 8-8-8-24 
Hard DriveHard DriveOptical DriveCooling
OCZ Agility2 40gb WD Blue 500GB Lite-On RASA waterblock 
OSMonitorKeyboardPower
Windows & Linux Samsung 1080p 2 ms Dell Thermaltake TR2-800 
CaseMouse
Cooler Master Elite 330 (was) cheap 
  hide details  
Reply
post #13 of 19
Thread Starter 
thanks for replies :-)

About Trixx: I've tried ALL! versions available on sapphire's website and the unofficial beta 4.21 but with no one voltage adjustment is working for me so the pencil mod was necassary to raise the voltage. Also i still think there are no programmable voltage regulators that would allow software side changes on gpu voltage on non reference sapphire cards.

About the Asus flash: It was just a question just because the BIOS of the MSI card was also possible :-)

@Drewmeister: Since i'm running the MSI BIOS on my XFX card i allready can set voltages using afterburner, as i wrote above: when i'm using trixx i can't but thanks for the tip. maybe it helps someone else.

@CL3P20: Lot's of thanks for your advise. Just because something went terribble wrong while testing all the AMD drivers(Desktop freezes after every reboot when eyefinity was enabled) i reinstalled my windows today. I'm gonna check overclocking abilities now again and respond here when i'm done.
About hardmodding the sapphire card: To raise the voltage i had to lower the resistance of the right resitor. This was done by adding graphite on its surface. When i solder a 10k potentiometer parallel to the ressitor the resulting resistance would be to low and i'd toast my gpu.
According to my measurement things are that way:
original resistance: 5.95kOhm -->1.2V
lowered resistance to 4.75kOhm --> 1.3xV

@EduFurtado: I may be all alone with my opinion but i think a cooling solution is always suitable as long components doesn't become to hot. Even if it's a stock cooler. Target clocks are around 1GHz, so i'll need high voltages and maybe another cooler for the sapphire card but i don't want to spend lots of money for a high end cooler as long as i don't know if the gpu(s) will reach those clocks.
post #14 of 19

*you would need to clean off pencil mod first.. then solder ... voltage control is much more stable with VR and you dont have to worry about volts "moving" over time as pencil wears off.

post #15 of 19
Thread Starter 
it's obvious that i'd have to clean the penciled resistor but soldering a trimmer parallel would be to much!

Just calculate it: R=(1/R1)+(1/R2)
resistor only-->5.95kOhm
resistor-pot(10kOhm) parallel--> 0.268kOhm
resistor-pot(5kOhm) parallel --> 0.368kOhm
resistor-pot(1kOhm) parallel --> 1.1.68kOhm
-->very huge ammount of voltage^^

That's why i think replacing would be the better solution...Or is there a mistake in my calculations?

Actual progress in my efforts: seems running 950MHz is stable @ 1.3V using CCC 12.3(8.95) Pre-Certified and AB 2.2 Beta 14 but figured out there's something weird with my memory...driver instant crashes when i raise memory clocks, no matter if i add 1 or 100MHz. So the fresh windows installation seems to be helpful but denies any memory tuning :-(

Priority is raising GPU clocks so i'm going to check if it's possible to go above 950MHz...

Update: Tried 975MHz, causes gamecrash when running Crysis TD. Still not sure wich of both cards is limiting :-(
Maybe anyone has got an idea:
GPU 1: Voltage drops from load value to idle value, GPU load drops to zero
GPU 2: Voltage value stays at load value and GPU keeps on 100% load in AB monitoring
OCP-Mod ftw?
Edited by uk3k - 2/22/12 at 7:25am
post #16 of 19

if stock resistance is already 5k ohms.. you would need a 100k to hard mod... not 10k 

 

VR = 20x stock 'R'

post #17 of 19
Thread Starter 
got the feeling we're talking not about the same resistor biggrin.gif

There's this one resistor that has to be penciled to lower it's resistance. Lower resistance means higher voltage. It's stock resistance is 5.95 kOhm so it has to been replaced by an 10kOhm trimmer. When it's done restistance can be lowered with the potentiometer below 5.95KOhm so voltage increases.

Actually i've decided to accept my 950Mhz, had some OCP resets running higher voltages on the XFX card. When there are new Kepler chips available i'll continue right here but until then i won't go any further like OCP mods.

I'd like to thank you all for your advise :-)

best regards
post #18 of 19

lowering resistance always = higher voltage   [only in rare cases is there reverse FB mod where decreasing resistance = decreased voltage]

 

 If you resistor is 5.9k ohms at stock... you DO NOT need to replace it at all.

You CAN solder a 100k ohm resistor inline and you will have the ability to set stock value again... or go lower for increased power output.

 

*The formula for calculating any VR size for a mod is as follows: 

 

[stock resistance *20 = starting resistance for VR size ]

 

 That said - you will fry your GPU using a 10k resistor/trimmer... as this will NOT be sufficient resistance when in line.

 

**Remember - you are not measuring the resistance of that actual resistor - you are measuring the total resistance of the circuit with that resistor inline. If you use 10k you will be sorry.. 

post #19 of 19
Thread Starter 
Got it now, thanks for your patience. Didn't had in mind that the whole circuit is measured.

To get a summary for further work in a few weeks/months depending on Nvidia's success with Kepler performance chips...Just don't want to f*ck up my cards as long as there is no really faster alternative available...those HD7970 are much to expensive atm as i need two of them to run my eyefinity setup properly xD

For the Sapphire card(pic also borrowed from radeon3d.org) OCP + VGPU mod:
lvslccjv.jpg

For the XFX card OCP mod:
4tt6resd.jpg

Is this correct now?
Where to hard mod for VGPU increase on the XFX card using a VR?
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Graphics Cards Volt Mods
Overclock.net › Forums › Volt Mods › General Volt Mods › Graphics Cards Volt Mods › HD5870 Voltmod Issues...